# Copyright 2020 The HuggingFace Team Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a clone of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


import collections
import copy
import gc
import inspect
import random
import tempfile
import unittest
import warnings
from pathlib import Path

import numpy as np
import pytest
from parameterized import parameterized

from transformers import (
    AutoConfig,
    AutoProcessor,
    AutoTokenizer,
    PreTrainedModel,
    is_torch_available,
    logging,
    pipeline,
    set_seed,
)
from transformers.testing_utils import (
    CaptureLogger,
    is_flaky,
    require_accelerate,
    require_flash_attn,
    require_flash_attn_3,
    require_flash_attn_4,
    require_optimum_quanto,
    require_torch,
    require_torch_accelerator,
    require_torch_gpu,
    require_torch_greater_or_equal,
    require_torch_multi_accelerator,
    set_config_for_less_flaky_test,
    set_model_for_less_flaky_test,
    slow,
    torch_device,
)
from transformers.utils import is_sklearn_available
from transformers.utils.generic import is_flash_attention_requested


if is_torch_available():
    import torch
    import torch.nn.functional as F
    from torch.nn.attention import SDPBackend, sdpa_kernel

    from transformers import (
        AutoModelForCausalLM,
        AutoModelForImageTextToText,
        AutoModelForSeq2SeqLM,
        AutoModelForSpeechSeq2Seq,
        BartForConditionalGeneration,
        BartTokenizer,
        DataCollatorWithFlattening,
        GPT2LMHeadModel,
        GPT2Tokenizer,
        ImageGPTForCausalImageModeling,
        SpeechEncoderDecoderModel,
    )
    from transformers.cache_utils import (
        Cache,
        DynamicCache,
        EncoderDecoderCache,
        LinearAttentionAndFullAttentionLayer,
        LinearAttentionLayer,
        QuantoQuantizedLayer,
        StaticCache,
    )
    from transformers.generation import (
        CompileConfig,
        GenerateBeamDecoderOnlyOutput,
        GenerateBeamEncoderDecoderOutput,
        GenerateDecoderOnlyOutput,
        GenerateEncoderDecoderOutput,
        GenerationConfig,
        LogitsProcessorList,
        MaxLengthCriteria,
        MinLengthLogitsProcessor,
        PromptLookupCandidateGenerator,
        StoppingCriteria,
        StoppingCriteriaList,
        SynthIDTextWatermarkingConfig,
        WatermarkDetector,
        WatermarkingConfig,
    )
    from transformers.generation.candidate_generator import (
        AssistedCandidateGenerator,
        AssistedCandidateGeneratorDifferentTokenizers,
    )
    from transformers.generation.utils import _speculative_sampling

from unittest.mock import patch


def is_moe_model(config):
    return getattr(config, "_experts_implementation", None) is not None


class GenerationTesterMixin:
    input_name = "input_ids"
    model_tester = None
    max_new_tokens = 3

    def prepare_config_and_inputs_for_generate(self, batch_size=2):
        config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()

        # We don't want a few model inputs in our model input dictionary for generation tests
        input_keys_to_ignore = [
            # we don't want encoder-decoder models to start from filled decoder ids
            "decoder_input_ids",
            "decoder_attention_mask",
            # we'll set cache use in each test differently
            "use_cache",
            # Ignore labels if it is in the input dict
            "labels",
            # model-specific exceptions should overload/overwrite this function
        ]
        filtered_inputs_dict = {
            k: v[:batch_size, ...] if isinstance(v, torch.Tensor) else v
            for k, v in inputs_dict.items()
            if k not in input_keys_to_ignore
        }

        # It is important set `eos_token_id` to `None` to avoid early stopping (would break for length-based checks)
        text_gen_config = config.get_text_config(decoder=True)
        if text_gen_config.eos_token_id is not None and text_gen_config.pad_token_id is None:
            text_gen_config.pad_token_id = (
                text_gen_config.eos_token_id
                if isinstance(text_gen_config.eos_token_id, int)
                else text_gen_config.eos_token_id[0]
            )
        text_gen_config.eos_token_id = None
        text_gen_config.forced_eos_token_id = None

        return config, filtered_inputs_dict

    def _get_logits_processor_kwargs(self, do_sample=False, config=None):
        logits_processor_kwargs = {
            "bad_words_ids": [[1, 0]],
            "repetition_penalty": 1.2,
            "remove_invalid_values": True,
        }
        if do_sample:
            logits_processor_kwargs.update(
                {
                    "top_k": 10,
                    "top_p": 0.7,
                    "temperature": 0.7,
                }
            )
        # TODO (joao, raushan): see this comment for a long-term fix
        # https://github.com/huggingface/transformers/pull/33593#issuecomment-2361824264)
        # This is a band-aid for VLM models, to ensure they don't generate image/video tokens which would cause them
        # to crash. On pretrained models this isn't a risk, as they are trained to not generate these tokens.
        if config is not None:
            for key in [
                "image_token_id",
                "video_token_id",
                "audio_token_id",
                "vision_start_token_id",
                "audio_start_token_id",
                "audio_end_token_id",
                "vision_end_token_id",
                "image_start_token_id",
                "image_end_token_id",
            ]:
                token_index = getattr(config, key, None)
                if token_index is None and hasattr(self, "model_tester"):
                    token_index = getattr(self.model_tester, key, None)
                if token_index is not None and token_index < config.get_text_config().vocab_size:
                    logits_processor_kwargs["bad_words_ids"].append([token_index])

        return logits_processor_kwargs

    def _get_beam_kwargs(self, num_return_sequences=1):
        beam_kwargs = {
            "early_stopping": False,
            "length_penalty": 2.0,
            "num_beams": 2,
            "num_return_sequences": num_return_sequences,
        }
        return beam_kwargs

    def _greedy_generate(
        self,
        model,
        inputs_dict,
        output_scores=False,
        output_logits=False,
        output_attentions=False,
        output_hidden_states=False,
        return_dict_in_generate=False,
        use_cache=True,
    ):
        logits_processor_kwargs = self._get_logits_processor_kwargs(do_sample=False, config=model.config)
        output_generate = model.generate(
            do_sample=False,
            num_beams=1,
            max_new_tokens=self.max_new_tokens,
            min_new_tokens=self.max_new_tokens,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            output_scores=output_scores,
            output_logits=output_logits,
            return_dict_in_generate=return_dict_in_generate,
            use_cache=use_cache,
            **logits_processor_kwargs,
            **inputs_dict,
        )

        return output_generate

    def _sample_generate(
        self,
        model,
        inputs_dict,
        num_return_sequences,
        output_scores=False,
        output_logits=False,
        output_attentions=False,
        output_hidden_states=False,
        return_dict_in_generate=False,
        use_cache=True,
    ):
        set_seed(42)
        logits_processor_kwargs = self._get_logits_processor_kwargs(do_sample=True, config=model.config)
        output_generate = model.generate(
            do_sample=True,
            num_beams=1,
            max_new_tokens=self.max_new_tokens,
            min_new_tokens=self.max_new_tokens,
            num_return_sequences=num_return_sequences,
            output_scores=output_scores,
            output_logits=output_logits,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict_in_generate=return_dict_in_generate,
            use_cache=use_cache,
            **logits_processor_kwargs,
            **inputs_dict,
        )

        return output_generate

    def _beam_search_generate(
        self,
        model,
        inputs_dict,
        beam_kwargs,
        output_scores=False,
        output_logits=False,
        output_attentions=False,
        output_hidden_states=False,
        return_dict_in_generate=False,
        use_cache=True,
    ):
        logits_processor_kwargs = self._get_logits_processor_kwargs(do_sample=False, config=model.config)
        output_generate = model.generate(
            do_sample=False,
            max_new_tokens=self.max_new_tokens,
            min_new_tokens=self.max_new_tokens,
            output_scores=output_scores,
            output_logits=output_logits,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict_in_generate=return_dict_in_generate,
            use_cache=use_cache,
            **beam_kwargs,
            **logits_processor_kwargs,
            **inputs_dict,
        )

        return output_generate

    def _beam_sample_generate(
        self,
        model,
        inputs_dict,
        beam_kwargs,
        output_scores=False,
        output_logits=False,
        output_attentions=False,
        output_hidden_states=False,
        return_dict_in_generate=False,
        use_cache=True,
    ):
        set_seed(42)
        logits_processor_kwargs = self._get_logits_processor_kwargs(do_sample=True, config=model.config)
        output_generate = model.generate(
            do_sample=True,
            max_new_tokens=self.max_new_tokens,
            min_new_tokens=self.max_new_tokens,
            output_scores=output_scores,
            output_logits=output_logits,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict_in_generate=return_dict_in_generate,
            use_cache=use_cache,
            **beam_kwargs,
            **logits_processor_kwargs,
            **inputs_dict,
        )

        return output_generate

    @pytest.mark.generate
    def test_greedy_generate(self):
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()

            model = model_class(config).to(torch_device).eval()
            output_generate = self._greedy_generate(model=model, inputs_dict=inputs_dict)

            if model.config.is_encoder_decoder:
                self.assertTrue(output_generate.shape[1] == self.max_new_tokens + 1)
            else:
                self.assertTrue(output_generate.shape[1] == self.max_new_tokens + inputs_dict["input_ids"].shape[1])

    @pytest.mark.generate
    def test_greedy_generate_dict_outputs(self):
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()
            if self.has_attentions:
                config._attn_implementation = "eager"  # can't output attentions otherwise

            model = model_class(config).to(torch_device).eval()
            output_generate = self._greedy_generate(
                model=model,
                inputs_dict=inputs_dict,
                output_scores=True,
                output_logits=True,
                output_hidden_states=True,
                output_attentions=self.has_attentions,
                return_dict_in_generate=True,
                use_cache=False,
            )

            if model.config.is_encoder_decoder:
                self.assertTrue(output_generate.sequences.shape[1] == self.max_new_tokens + 1)
                self.assertIsInstance(output_generate, GenerateEncoderDecoderOutput)
            else:
                self.assertTrue(
                    output_generate.sequences.shape[1] == self.max_new_tokens + inputs_dict["input_ids"].shape[1]
                )
                self.assertIsInstance(output_generate, GenerateDecoderOnlyOutput)

            self._check_generate_outputs(output_generate, model.config)

    @pytest.mark.generate
    def test_greedy_generate_dict_outputs_use_cache(self):
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()
            if self.has_attentions:
                config._attn_implementation = "eager"  # can't output attentions otherwise

            if not hasattr(config.get_text_config(), "use_cache"):
                self.skipTest(reason=f"{model_class.__name__} doesn't support caching")
            if any(model_name in model_class.__name__.lower() for model_name in ["rwkv"]):
                self.skipTest(reason="Won't fix: model with non-standard dictionary output shapes")

            config.is_decoder = True
            model = model_class(config).to(torch_device).eval()
            output_generate = self._greedy_generate(
                model=model,
                inputs_dict=inputs_dict,
                output_scores=True,
                output_logits=True,
                output_hidden_states=True,
                output_attentions=self.has_attentions,
                return_dict_in_generate=True,
                use_cache=True,  # Enable cache
            )

            if model.config.is_encoder_decoder:
                self.assertTrue(output_generate.sequences.shape[1] == self.max_new_tokens + 1)
            else:
                self.assertTrue(
                    output_generate.sequences.shape[1] == self.max_new_tokens + inputs_dict["input_ids"].shape[1]
                )

            self._check_generate_outputs(output_generate, model.config, use_cache=True)

    @pytest.mark.generate
    def test_sample_generate(self):
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()

            model = model_class(config).to(torch_device).eval()
            output_generate = self._sample_generate(model=model, inputs_dict=inputs_dict, num_return_sequences=1)

            if model.config.is_encoder_decoder:
                self.assertTrue(output_generate.shape[1] == self.max_new_tokens + 1)
            else:
                self.assertTrue(output_generate.shape[1] == self.max_new_tokens + inputs_dict["input_ids"].shape[1])

    @pytest.mark.generate
    def test_sample_generate_dict_output(self):
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()
            if self.has_attentions:
                config._attn_implementation = "eager"  # can't output attentions otherwise

            model = model_class(config).to(torch_device).eval()
            output_generate = self._sample_generate(
                model=model,
                inputs_dict=inputs_dict,
                num_return_sequences=2,
                output_scores=True,
                output_logits=True,
                output_hidden_states=True,
                output_attentions=self.has_attentions,
                return_dict_in_generate=True,
                use_cache=False,
            )

            if model.config.is_encoder_decoder:
                self.assertTrue(output_generate.sequences.shape[1] == self.max_new_tokens + 1)
                self.assertIsInstance(output_generate, GenerateEncoderDecoderOutput)
            else:
                self.assertTrue(
                    output_generate.sequences.shape[1] == self.max_new_tokens + inputs_dict["input_ids"].shape[1]
                )
                self.assertIsInstance(output_generate, GenerateDecoderOnlyOutput)

            self._check_generate_outputs(output_generate, model.config, num_return_sequences=2)

    @pytest.mark.generate
    def test_beam_search_generate(self):
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()

            model = model_class(config).to(torch_device).eval()

            beam_kwargs = self._get_beam_kwargs()
            output_generate = self._beam_search_generate(model=model, inputs_dict=inputs_dict, beam_kwargs=beam_kwargs)

            if model.config.is_encoder_decoder:
                self.assertTrue(output_generate.shape[1] == self.max_new_tokens + 1)
            else:
                self.assertTrue(output_generate.shape[1] == self.max_new_tokens + inputs_dict["input_ids"].shape[1])

    @pytest.mark.generate
    def test_beam_search_generate_dict_output(self):
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()
            if self.has_attentions:
                config._attn_implementation = "eager"  # can't output attentions otherwise

            model = model_class(config).to(torch_device).eval()
            beam_kwargs = self._get_beam_kwargs()
            output_generate = self._beam_search_generate(
                model=model,
                inputs_dict=inputs_dict,
                beam_kwargs=beam_kwargs,
                output_scores=True,
                output_logits=True,
                output_hidden_states=True,
                output_attentions=self.has_attentions,
                return_dict_in_generate=True,
                use_cache=False,
            )
            if model.config.is_encoder_decoder:
                self.assertTrue(output_generate.sequences.shape[1] == self.max_new_tokens + 1)
                self.assertIsInstance(output_generate, GenerateBeamEncoderDecoderOutput)
            else:
                self.assertTrue(
                    output_generate.sequences.shape[1] == self.max_new_tokens + inputs_dict["input_ids"].shape[1]
                )
                self.assertIsInstance(output_generate, GenerateBeamDecoderOnlyOutput)

            self._check_generate_outputs(
                output_generate,
                model.config,
                num_return_sequences=beam_kwargs["num_return_sequences"],
                num_beams=beam_kwargs["num_beams"],
            )

    @pytest.mark.generate
    def test_beam_search_generate_dict_outputs_use_cache(self):
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()

            if not hasattr(config.get_text_config(), "use_cache"):
                self.skipTest(reason=f"{model_class.__name__} doesn't support caching")
            if any(model_name in model_class.__name__.lower() for model_name in ["rwkv"]):
                self.skipTest(reason="Won't fix: model with non-standard dictionary output shapes")

            if self.has_attentions:
                config._attn_implementation = "eager"  # can't output attentions otherwise
            model = model_class(config).to(torch_device).eval()
            beam_kwargs = self._get_beam_kwargs()

            config.is_decoder = True
            model = model_class(config).to(torch_device).eval()
            output_generate = self._beam_search_generate(
                model=model,
                inputs_dict=inputs_dict,
                beam_kwargs=beam_kwargs,
                output_scores=True,
                output_logits=True,
                output_hidden_states=True,
                output_attentions=self.has_attentions,
                return_dict_in_generate=True,
                use_cache=True,  # Enable cache
            )

            if model.config.is_encoder_decoder:
                self.assertTrue(output_generate.sequences.shape[1] == self.max_new_tokens + 1)
            else:
                self.assertTrue(
                    output_generate.sequences.shape[1] == self.max_new_tokens + inputs_dict["input_ids"].shape[1]
                )

            self._check_generate_outputs(
                output_generate,
                model.config,
                use_cache=True,
                num_return_sequences=beam_kwargs["num_return_sequences"],
                num_beams=beam_kwargs["num_beams"],
            )

    @require_accelerate
    @require_torch_multi_accelerator
    @pytest.mark.generate
    def test_model_parallel_beam_search(self):
        for model_class in self.all_generative_model_classes:
            if model_class._no_split_modules is None:
                continue

            config, inputs_dict = self.prepare_config_and_inputs_for_generate()

            model = model_class(config).eval()
            with tempfile.TemporaryDirectory() as tmp_dir:
                model.cpu().save_pretrained(tmp_dir)
                new_model = model_class.from_pretrained(tmp_dir, device_map="auto")
                if not hasattr(new_model, "hf_device_map") or len(set(new_model.hf_device_map.values())) == 1:
                    self.skipTest(reason="Model is not distributed across multiple devices")

                new_model.generate(
                    max_new_tokens=self.max_new_tokens,
                    num_beams=2,
                    **inputs_dict,
                )

    @pytest.mark.generate
    def test_beam_sample_generate(self):
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()

            model = model_class(config).to(torch_device).eval()
            beam_kwargs = self._get_beam_kwargs()
            output_generate = self._beam_sample_generate(
                model=model,
                inputs_dict=inputs_dict,
                beam_kwargs=beam_kwargs,
            )

            if model.config.is_encoder_decoder:
                self.assertTrue(output_generate.shape[1] == self.max_new_tokens + 1)
            else:
                self.assertTrue(output_generate.shape[1] == self.max_new_tokens + inputs_dict["input_ids"].shape[1])

    @pytest.mark.generate
    def test_beam_sample_generate_dict_output(self):
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()
            if self.has_attentions:
                config._attn_implementation = "eager"  # can't output attentions otherwise

            model = model_class(config).to(torch_device).eval()
            beam_kwargs = self._get_beam_kwargs()

            output_generate = self._beam_sample_generate(
                model=model,
                inputs_dict=inputs_dict,
                beam_kwargs=beam_kwargs,
                output_scores=True,
                output_logits=True,
                output_hidden_states=True,
                output_attentions=self.has_attentions,
                return_dict_in_generate=True,
                use_cache=False,
            )

            if model.config.is_encoder_decoder:
                self.assertTrue(output_generate.sequences.shape[1] == self.max_new_tokens + 1)
                self.assertIsInstance(output_generate, GenerateBeamEncoderDecoderOutput)
            else:
                self.assertTrue(
                    output_generate.sequences.shape[1] == self.max_new_tokens + inputs_dict["input_ids"].shape[1]
                )
                self.assertIsInstance(output_generate, GenerateBeamDecoderOnlyOutput)

            self._check_generate_outputs(
                output_generate,
                model.config,
                num_return_sequences=beam_kwargs["num_return_sequences"],
                num_beams=beam_kwargs["num_beams"],
            )

    @pytest.mark.generate
    def test_generate_without_input_ids(self):
        config, _ = self.prepare_config_and_inputs_for_generate()

        # if no bos token id => cannot generate from None
        if config.get_text_config(decoder=True).bos_token_id is None:
            self.skipTest(reason="bos_token_id is None")

        # hack in case they are equal, otherwise the attn mask will be [0]
        if config.get_text_config(decoder=True).bos_token_id == config.get_text_config(decoder=True).pad_token_id:
            config.get_text_config(decoder=True).pad_token_id = None

        for model_class in self.all_generative_model_classes:
            model = model_class(config).to(torch_device)
            model.eval()

            output_ids_generate = model.generate(
                do_sample=False, max_new_tokens=self.max_new_tokens, remove_invalid_values=True
            )
            self.assertIsNotNone(output_ids_generate)

    @parameterized.expand([("random",), ("same",)])
    @pytest.mark.generate
    def test_assisted_decoding_matches_greedy_search(self, assistant_type):
        # This test ensures that the assisted generation does not introduce output changes over greedy search.
        # See https://github.com/huggingface/transformers/issues/25420#issuecomment-1775317535 for more info.
        # NOTE: It breaks the pattern in the tests above, for multiple reasons:
        # - assisted_decoding, contrarily to the other methods, can't be called on its own (e.g. needs to
        # prepare the assistant encoder outputs in the main generate body);
        # - assisted_decoding does not support `use_cache = False`
        # - assisted_decoding does not support `batch_size > 1`

        for model_class in self.all_generative_model_classes:
            if model_class._is_stateful:
                self.skipTest(reason="Stateful models don't support assisted generation")
            if any(model_name in model_class.__name__.lower() for model_name in ["reformer"]):
                self.skipTest(reason="Won't fix: old model with different cache format")
            if any(
                model_name in model_class.__name__.lower()
                for model_name in [
                    "moshi",
                    "git",
                    "prophetnet",
                    "mllama",  # special cache sizes
                    "blip2",  # overridden `generate()` all BLIP models
                    "instructblip",
                    "instructblipvideo",
                ]
            ):
                self.skipTest(reason="May fix in the future: need model-specific fixes")

            # Set seed for deterministic test - ensures reproducible model initialization and inputs
            set_seed(42)
            # enable cache
            config, inputs_dict = self.prepare_config_and_inputs_for_generate(batch_size=1)
            set_config_for_less_flaky_test(config)

            # force eager attention to support output attentions
            if self.has_attentions:
                config._attn_implementation = "eager"

            # NOTE: assisted generation only works with cache on at the moment.
            if not hasattr(config.get_text_config(), "use_cache"):
                self.skipTest(reason=f"{model_class.__name__} doesn't support caching")

            config.is_decoder = True
            model = model_class._from_config(config, attn_implementation="eager").to(torch_device).eval()
            set_model_for_less_flaky_test(model)
            config = model.config
            # Sets assisted generation arguments such that:
            # a) no EOS is generated, to ensure generation doesn't break early
            # b) the assistant model always generates two tokens when it is called, to ensure the input preparation of
            #    the assistant model is correct
            # c) there are at least two forward passes in the main model, to ensure the input preparation of
            #    the main model is correct
            # d) use a cache type compatible with rollbacks (only dynamic cache atm). Otherwise, there may be
            #     differences vs model-specific default cache
            generation_kwargs = {
                "eos_token_id": -1,  # see a)
                "max_new_tokens": 4,  # see c)
                "num_beams": 1,
                "do_sample": False,
                "output_scores": True,
                "output_logits": True,
                "output_hidden_states": True,
                "output_attentions": self.has_attentions,
                "return_dict_in_generate": True,
                "use_cache": True,
                "cache_implementation": "dynamic_full",  # see d)
            }
            logits_processor_kwargs = self._get_logits_processor_kwargs(config=model.config)

            output_greedy = model.generate(**generation_kwargs, **inputs_dict, **logits_processor_kwargs)

            # test with the same assistant model or randomly init one
            # in the first case all candidate tokens are accepted, in the second none is accepted
            # case when some are accepted and some not is hard to reproduce, so let's hope this catches most errors :)
            if assistant_type == "random":
                assistant_model = model_class(config).to(torch_device).eval()
            else:
                assistant_model = model
            assistant_model.config._attn_implementation = "eager"
            assistant_model.generation_config.num_assistant_tokens = 2  # see b)
            assistant_model.generation_config.num_assistant_tokens_schedule = "constant"  # see b)
            generation_kwargs.update({"assistant_model": assistant_model})
            output_assisted = model.generate(**generation_kwargs, **inputs_dict, **logits_processor_kwargs)

            # some models requires larger tolerance
            if model.config.model_type in ["vibevoice_asr"]:
                atol = rtol = 5e-3
            elif is_moe_model(config):
                atol = rtol = 1e-3
            else:
                atol = rtol = 1e-5

            # The two outputs must match and their shape must be as expected
            assert_similar_generate_outputs(output_greedy, output_assisted, atol=atol, rtol=rtol)
            for output in (output_greedy, output_assisted):
                self._check_generate_outputs(output, model.config, use_cache=True)

    @pytest.mark.generate
    @is_flaky
    def test_prompt_lookup_decoding_matches_greedy_search(self):
        # This test ensures that the prompt lookup generation does not introduce output changes over greedy search.
        # This test is mostly a copy of test_assisted_decoding_matches_greedy_search

        for model_class in self.all_generative_model_classes:
            if model_class._is_stateful:
                self.skipTest(reason="Stateful models don't support assisted generation")
            old_models = [  # models that we won't commit resources fixing because they are old and have little usage
                # reformer: has a different cache format
                "reformer",
                # imagegpt: the output lm head uses `vocab_size - 1` tokens, so the `NoBadWordsLogitsProcessor` used
                # by prompt lookup may fail
                "imagegpt",
            ]
            if any(model_name in model_class.__name__.lower() for model_name in old_models):
                self.skipTest(reason="Won't fix: old model")
            if any(
                model_name in model_class.__name__.lower()
                for model_name in [
                    "moshi",
                    "git",
                    "prophetnet",
                    "mllama",  # special cache sizes
                    "blip2",  # overridden `generate()` for all BLIP models
                    "instructblip",
                    "instructblipvideo",
                ]
            ):
                self.skipTest(reason="May fix in the future: need model-specific fixes")

            # Set seed for deterministic test - ensures reproducible model initialization and inputs
            set_seed(42)
            # enable cache
            config, inputs_dict = self.prepare_config_and_inputs_for_generate(batch_size=1)

            # force eager attention to support output attentions
            if self.has_attentions:
                config._attn_implementation = "eager"

            # NOTE: assisted generation only works with cache on at the moment.
            if not hasattr(config.get_text_config(), "use_cache"):
                self.skipTest(reason=f"{model_class.__name__} doesn't support caching")

            config.is_decoder = True
            model = model_class(config).to(torch_device).eval()
            # Sets assisted generation arguments such that:
            # a) no EOS is generated, to ensure generation doesn't break early
            # b) the prompt lookup tries to give the model 2 tokens, to ensure the input preparation of
            #    prompt lookup is correct
            # c) there are at least two forward passes in the main model, to ensure the input preparation of
            #    the main model is correct
            # d) use a cache type compatible with rollbacks (only dynamic cache atm). Otherwise, there may be
            #     differences vs model-specific default cache
            generation_kwargs = {
                "eos_token_id": -1,  # see a)
                "max_new_tokens": 4,  # see c)
                "num_beams": 1,
                "do_sample": False,
                "output_scores": True,
                "output_logits": True,
                "output_hidden_states": True,
                "output_attentions": self.has_attentions,
                "return_dict_in_generate": True,
                "use_cache": True,
                "cache_implementation": "dynamic_full",  # see d)
            }
            logits_processor_kwargs = self._get_logits_processor_kwargs(config=model.config)

            output_greedy = model.generate(**generation_kwargs, **inputs_dict, **logits_processor_kwargs)

            generation_kwargs.update({"prompt_lookup_num_tokens": 2})  # see b)
            output_prompt_lookup = model.generate(**generation_kwargs, **inputs_dict, **logits_processor_kwargs)

            # The two outputs must match and their shape must be as expected
            if is_moe_model(config):
                atol = rtol = 1e-3
            else:
                atol = rtol = 1e-5
            assert_similar_generate_outputs(output_greedy, output_prompt_lookup, atol=atol, rtol=rtol)
            for output in (output_greedy, output_prompt_lookup):
                self._check_generate_outputs(output, model.config, use_cache=True)

    @pytest.mark.generate
    def test_assisted_decoding_sample(self):
        # In this test we don't check assisted vs non-assisted output -- seeded assisted decoding with sample will not
        # match sample for the same seed, as the forward pass does not return the exact same logits (due to matmul with
        # different shapes, see https://github.com/huggingface/transformers/issues/25420#issuecomment-1775317535).
        for model_class in self.all_generative_model_classes:
            if model_class._is_stateful:
                self.skipTest(reason="Stateful models don't support assisted generation")
            if any(model_name in model_class.__name__.lower() for model_name in ["reformer"]):
                self.skipTest(reason="Won't fix: old model with different cache format")
            if any(
                model_name in model_class.__name__.lower()
                for model_name in [
                    "moshi",
                    "git",
                    "prophetnet",
                    "mllama",  # special cache sizes
                    "blip2",  # overridden `generate()` for all BLIP models
                    "instructblip",
                    "instructblipvideo",
                ]
            ):
                self.skipTest(reason="May fix in the future: need model-specific fixes")

            # enable cache
            config, inputs_dict = self.prepare_config_and_inputs_for_generate(batch_size=1)

            # force eager attention to support output attentions
            if self.has_attentions:
                config._attn_implementation = "eager"

            # NOTE: assisted generation only works with cache on at the moment.
            if not hasattr(config.get_text_config(), "use_cache"):
                self.skipTest(reason=f"{model_class.__name__} doesn't support caching")

            config.is_decoder = True
            model = model_class._from_config(config, attn_implementation="eager").to(torch_device).eval()
            config = model.config
            # Sets assisted generation arguments such that:
            # a) no EOS is generated, to ensure generation doesn't break early
            # b) the assistant model always generates two tokens when it is called, to ensure the input preparation of
            #    the assistant model is correct
            # c) there are at least two forward passes in the main model, to ensure the input preparation of
            #    the main model is correct
            # d) use a cache type compatible with rollbacks (only dynamic cache atm). Otherwise, there may be
            #     differences vs model-specific default cache
            assistant_model = model
            assistant_model.generation_config.num_assistant_tokens = 2  # see b)
            assistant_model.generation_config.num_assistant_tokens_schedule = "constant"  # see b)
            generation_kwargs = {
                "eos_token_id": -1,  # see a)
                "max_new_tokens": 4,  # see c)
                "num_beams": 1,
                "do_sample": True,
                "assistant_model": assistant_model,
                "output_scores": True,
                "output_logits": True,
                "output_hidden_states": True,
                "output_attentions": self.has_attentions,
                "return_dict_in_generate": True,
                "use_cache": True,
                "cache_implementation": "dynamic_full",  # see d)
            }
            logits_processor_kwargs = self._get_logits_processor_kwargs(config=model.config)
            output_assisted = model.generate(**generation_kwargs, **inputs_dict, **logits_processor_kwargs)

            self._check_generate_outputs(output_assisted, config, use_cache=True)

    @pytest.mark.generate
    def test_prompt_lookup_decoding_stops_at_eos(self):
        # This test ensures that the prompt lookup generation stops at eos token and does not suggest more tokens
        # (see https://github.com/huggingface/transformers/pull/31301)

        # The main idea is to have an ngram (unigram in our case) that is repeated twice in the input ids.
        # First time at the very end, so input ends with the unigrams, and second any arbitrary location.
        # Also, we need an EOS token which will be injected just after the arbitrary located ngram.
        # We verify that PLD will not copy and propose candidated that contain an EOS token, even if there are overlapping ngrams
        # in input ids. Otherwise a proposed EOS along with the trailing (ngrams-1) tokens might be accepted by the target model.
        # That seems as if the model "generated" and EOS but didn't stop from user's perspective

        input_ids = torch.randint(1, 50, (1, 10), device=torch_device)  # generate inputs in range from 1-50
        arbitrary_ngram = 51  # this is the arbitrary ngram, specifically chosen OOV to prevent flaky tests
        input_ids[:, 3] = arbitrary_ngram  # set pre-eos to arbitrary_ngram which is for sure not present in inputs
        input_ids[:, -1] = arbitrary_ngram  # put arbitrary_ngram in the end for the necessary match to happen

        eos_token_id = torch.tensor([0], device=torch_device)
        input_ids[:, 4] = eos_token_id  # inject eos-token-id in input ids so that it is located after arbitrary_ngram

        # init cand geenerator with max_matching_ngram_size=1 to match per-token
        candidate_generator = PromptLookupCandidateGenerator(
            eos_token_id=eos_token_id, num_output_tokens=4, max_matching_ngram_size=1
        )
        output_prompt_lookup = candidate_generator.get_candidates(input_ids)[0]

        # PLD shouldn't propose any new tokens based on eos-match
        self.assertTrue(output_prompt_lookup.shape[-1] == 10)

    @pytest.mark.generate
    def test_left_padding_compatibility(
        self, unpadded_custom_inputs: dict | None = None, padded_custom_inputs: dict | None = None
    ):
        """
        Tests that adding left-padding yields the same logits as the original input. Exposes arguments for custom
        inputs for overwrites, to prevent full rewrites of the test when all we need is model-specific input handling.

        ! If you overwrite this test, make sure to document why you need to overwrite it !

        NOTE: left-padding results in small numerical differences. This is expected.
        See https://github.com/huggingface/transformers/issues/25420#issuecomment-1775317535

        Args:
            unpadded_custom_inputs (`dict`, *optional*):
                Used in test overwrites. Custom inputs to add/overwrite over the default test inputs.
            padded_custom_inputs (`dict`, *optional*):
                Used in test overwrites. Custom inputs to add/overwrite over the padded test input handcrafted in this
                test. Commonly used e.g. with multimodal cross attention masks.
        """

        # First, filter out models that don't support left padding
        # 1. The model must support padding
        if not self.has_attentions:
            self.skipTest(reason="This model doesn't support padding.")
        # 2. [encoder-decoder] The model must be a decoder-only architecture. Encoder-based architectures can use
        # right-padding in their (encoder) inputs. Encoder-decoder may use left-padding on their decoder inputs
        # [TODO: lift this restriction? technically, we can test padding the decoder inputs.]
        decoder_only_classes = []
        for model_class in self.all_generative_model_classes:
            config, _ = self.prepare_config_and_inputs_for_generate()
            if config.is_encoder_decoder:
                continue
            else:
                decoder_only_classes.append(model_class)
        if len(decoder_only_classes) == 0:
            self.skipTest(reason="No decoder-only architecture available for this model.")
        # 3. [old models] Decoder-only architectures derived from encoder-decoder models could support it in theory,
        # but we haven't added support for it yet. We skip these models for now.
        has_encoder_attributes = any(
            attr_name
            for attr_name in config.to_dict()
            if attr_name.startswith("encoder") and attr_name != "encoder_no_repeat_ngram_size"
        )
        if has_encoder_attributes:
            self.skipTest(
                reason="The decoder-only derived from encoder-decoder models are not expected to support left-padding."
            )

        # Now we can start testing
        unpadded_custom_inputs = unpadded_custom_inputs or {}
        padded_custom_inputs = padded_custom_inputs or {}

        def _prepare_model_kwargs(model_inputs, signature):
            model_kwargs = {"input_ids": model_inputs["input_ids"], "attention_mask": model_inputs["attention_mask"]}
            if "position_ids" in signature:
                position_ids = torch.cumsum(model_inputs["attention_mask"], dim=-1) - 1
                position_ids.masked_fill_(model_inputs["attention_mask"] == 0, 1)
                model_kwargs["position_ids"] = position_ids
            # forward all other inputs, if they are in the signature
            model_kwargs.update({k: v for k, v in model_inputs.items() if k not in model_kwargs and k in signature})
            return model_kwargs

        for model_class in decoder_only_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()
            model = model_class(config).to(torch_device).eval()
            signature = inspect.signature(model.forward).parameters.keys()

            # No cache to simplify the test (some models need careful init)
            model.generation_config.use_cache = False
            inputs_dict.update(unpadded_custom_inputs)
            # special case: an inexistent `attention_mask` is a full mask
            inputs_dict["attention_mask"] = inputs_dict.get("attention_mask", None)
            if inputs_dict["attention_mask"] is None:
                inputs_dict["attention_mask"] = torch.ones_like(inputs_dict["input_ids"])

            # Get output logits from inputs without padding
            model_kwargs_wo_padding = _prepare_model_kwargs(inputs_dict, signature)
            next_logits_wo_padding = model(**model_kwargs_wo_padding).logits[:, -1, :]

            # Prepare padding on common inputs (pad length 32)
            input_ids = inputs_dict["input_ids"]
            attention_mask = inputs_dict["attention_mask"]
            pad_token_id = getattr(config.get_text_config(decoder=True), "pad_token_id", None) or 0
            pad_size = (input_ids.shape[0], 32, *input_ids.shape[2:])
            padding = torch.ones(pad_size, dtype=input_ids.dtype, device=torch_device) * pad_token_id

            padded_inputs_dict = copy.deepcopy(inputs_dict)
            padded_inputs_dict["input_ids"] = torch.cat((padding, input_ids), dim=1)
            padded_inputs_dict["attention_mask"] = torch.cat(
                (torch.zeros(pad_size[:2], dtype=input_ids.dtype, device=torch_device), attention_mask), dim=1
            )
            if inputs_dict.get("token_type_ids") is not None:
                padded_inputs_dict["token_type_ids"] = torch.cat(
                    (
                        # Assumption: `0` is a good default value for padding token type ids
                        torch.zeros(pad_size[:2], dtype=input_ids.dtype, device=torch_device),
                        inputs_dict["token_type_ids"],
                    ),
                    dim=1,
                )

            if inputs_dict.get("mm_token_type_ids") is not None:
                padded_inputs_dict["mm_token_type_ids"] = torch.cat(
                    (
                        # `0` is a default value of text-modality type ids
                        torch.zeros(pad_size[:2], dtype=input_ids.dtype, device=torch_device),
                        inputs_dict["mm_token_type_ids"],
                    ),
                    dim=1,
                )

            padded_inputs_dict.update(padded_custom_inputs)

            model_kwargs_with_padding = _prepare_model_kwargs(padded_inputs_dict, signature)
            next_logits_with_padding = model(**model_kwargs_with_padding).logits[:, -1, :]

            # They should result in very similar logits
            torch.testing.assert_close(next_logits_wo_padding, next_logits_with_padding, rtol=1e-5, atol=1e-5)

    @pytest.mark.generate
    def test_past_key_values_format(self):
        """
        Test that the KV cache is formatted correctly.
        Having a standard KV cache format is important for a consistent API (and for advanced generation methods).
        """
        for model_class in self.all_generative_model_classes:
            config, inputs = self.model_tester.prepare_config_and_inputs_for_common()

            # If it doesn't support cache, skip the test
            decoder_config = config.get_text_config(decoder=True)
            if not hasattr(decoder_config, "use_cache"):
                self.skipTest(reason=f"{model_class.__name__} doesn't support caching")

            model = model_class(config).to(torch_device)
            model = model.eval()
            if "use_cache" not in inputs:
                inputs["use_cache"] = True
            outputs = model(**inputs)

            if "past_key_values" not in outputs:
                self.skipTest(reason="This model doesn't return `past_key_values`")

            cache = outputs["past_key_values"]
            if config.is_encoder_decoder:
                batch_size, seq_length = inputs["decoder_input_ids"].shape[:2]
            else:
                batch_size, seq_length = inputs["input_ids"].shape[:2]

            # Check the format
            self._check_past_key_values_for_generate(batch_size, cache, seq_length, decoder_config)

    @pytest.mark.generate
    def test_generate_from_random_inputs_embeds(self):
        """
        Text-only: Tests that different `inputs_embeds` generate different outputs in models with `main_input=="input_ids"`.
        Some models have 'images' as main input and thus can't generate with random text embeddings.
        See `test_generate_from_inputs_embeds` for more general checks.
        """
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()

            if config.is_encoder_decoder:
                continue
            config.is_decoder = True

            model = model_class(config).to(torch_device).eval()
            if "inputs_embeds" not in inspect.signature(model.prepare_inputs_for_generation).parameters:
                continue

            #  No easy fix, let's skip the test for now
            has_complex_embeds_computation = any(
                model_name in model_class.__name__.lower() for model_name in ["moshi"]
            )

            if model_class.main_input_name != "input_ids" or has_complex_embeds_computation:
                self.skipTest(
                    "The model's main input name in not `input_ids` and we need kwargs from input dict as well."
                )

            if hasattr(config, "scale_embedding"):
                config.scale_embedding = False

            generation_kwargs = {
                "return_dict_in_generate": True,
                "output_scores": True,
                "do_sample": False,
                "max_new_tokens": 5,
                "min_new_tokens": 5,  # generate exactly 5 tokens
            }

            input_ids = inputs_dict.pop("input_ids")
            inputs_embeds = model.get_input_embeddings()(input_ids)
            outputs_from_embeds = model.generate(input_ids, inputs_embeds=inputs_embeds, **generation_kwargs)

            # If we pass different inputs_embeds, we should get different outputs (the output text may be the
            # same, but the logits will almost surely be different)
            random_embeds = torch.rand_like(inputs_embeds)
            outputs_from_rand_embeds = model.generate(
                input_ids=input_ids, inputs_embeds=random_embeds, **generation_kwargs
            )
            for i in range(len(outputs_from_rand_embeds.scores)):
                self.assertFalse(torch.allclose(outputs_from_embeds.scores[i], outputs_from_rand_embeds.scores[i]))

    @pytest.mark.generate
    @parameterized.expand([("greedy", 1), ("beam search", 2)])
    def test_generate_from_inputs_embeds(self, _, num_beams):
        """Tests that we can generate from `inputs_embeds` instead of `input_ids` in LLMs, VLMs, etc"""
        # When supported, tests that the decoder model can generate from `inputs_embeds` instead of `input_ids`
        # if fails, you should probably update the `prepare_inputs_for_generation` function
        for model_class in self.all_generative_model_classes:
            # Set seed for deterministic test - ensures reproducible model initialization and inputs
            set_seed(42)
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()

            # This test is for decoder-only models (encoder-decoder models have native input embeddings support in the
            # decoder)
            if config.is_encoder_decoder:
                continue
            config.is_decoder = True

            set_config_for_less_flaky_test(config)
            # Skip models without explicit support
            model = model_class(config).to(torch_device).eval()
            set_model_for_less_flaky_test(model)
            if "inputs_embeds" not in inspect.signature(model.prepare_inputs_for_generation).parameters:
                continue

            # There are a few exception patterns in this test:
            # 1 - Complex `inputs_embeds` computation, i.e. the correct computation of inputs embeds is more complex
            # than calling the embedding layer with `input_ids`. Subcases of this exception:
            #   1.A - Ignore `scale_embedding`, if the model supports it (it is controlled by a model-dependent flag)
            if hasattr(config, "scale_embedding"):
                config.scale_embedding = False
            # HACK - in the case of granite speech, input_features and inputs_embeds are mutually exclusive;
            # this is similar to VLMs and should likely be standardized for similar audio models in the future,
            # then made generic here.
            if "granitespeech" in model_class.__name__.lower():
                inputs_dict.pop("input_features", None)

            #   1.B - No easy fix, let's skip the check that compares the outputs from `input_ids` and `inputs_embeds`
            has_complex_embeds_computation = any(
                model_name in model_class.__name__.lower() for model_name in ["moshi"]
            )
            # 2 - `inputs_dict` doesn't contain `attention_mask`. When `attention_mask` is not passed to generate,
            # we infer it from `input_ids`. The last test case will fail if there is a pad token in the original input.
            missing_attention_mask = "attention_mask" not in inputs_dict

            # Traditional way of generating text
            input_ids = inputs_dict.pop("input_ids")
            generation_kwargs = {
                "return_dict_in_generate": True,
                "output_scores": True,
                "num_beams": num_beams,
                "do_sample": False,
                "max_new_tokens": 5,
                "min_new_tokens": 5,  # generate exactly 5 tokens
                "use_cache": True,
            }
            outputs_from_ids = model.generate(input_ids=input_ids, **generation_kwargs, **inputs_dict)
            self.assertEqual(outputs_from_ids.sequences.shape[:2], (input_ids.shape[0], input_ids.shape[1] + 5))

            # Same thing, but from input embeddings (`input_ids` is passed so the prompt is present in the output).
            # The output of the two calls should be the same.
            inputs_embeds = model.get_input_embeddings()(input_ids)
            outputs_from_embeds = model.generate(
                input_ids=input_ids, inputs_embeds=inputs_embeds, **generation_kwargs, **inputs_dict
            )
            if is_moe_model(config):
                atol = rtol = 1e-3
            else:
                atol = rtol = 1e-5
            if not has_complex_embeds_computation:
                assert_similar_generate_outputs(outputs_from_ids, outputs_from_embeds, atol=atol, rtol=rtol)

            # input_ids is not a required input on most models -- if we don't pass it, the newly generated tokens will
            # be the same
            if not missing_attention_mask:
                outputs_from_embeds_wo_ids = model.generate(
                    inputs_embeds=inputs_embeds, **generation_kwargs, **inputs_dict
                )
                outputs_from_embeds.sequences = outputs_from_embeds.sequences[:, inputs_embeds.shape[1] :]
                assert_similar_generate_outputs(outputs_from_embeds_wo_ids, outputs_from_embeds, atol=atol, rtol=rtol)

    @pytest.mark.generate
    def test_generate_from_inputs_embeds_with_static_cache(self):
        """
        Test that StaticCache can generate from inputs_embeds and calculates max_cache_length
        correctly in `generate()`. We force the model to not stop generation until max-length is reached
        to verify that the cache length is indeed set correctly and we don't run out of index when slicing the cache.
        """
        for model_class in self.all_generative_model_classes:
            # Here, we should ideally not skip any model, and test them all. However, some old models cannot correctly
            # use a static cache because they don't create the causal masks correctly.
            # TODO: cyril -> relax this by adding a `_support_static_cache` attribute
            if not model_class._can_compile_fullgraph:
                self.skipTest(reason="This model does not support the static cache format")

            config, inputs_dict = self.prepare_config_and_inputs_for_generate()

            if config.is_encoder_decoder:
                self.skipTest(reason="This model is encoder-decoder and has Encoder-Decoder Cache")

            model = model_class(config).to(torch_device).eval()
            if "inputs_embeds" not in inspect.signature(model.prepare_inputs_for_generation).parameters:
                self.skipTest(reason="This model does not support `inputs_embeds` in generation")

            input_ids = inputs_dict.pop("input_ids")

            model.generation_config.use_cache = True
            model.config.is_decoder = True
            batch_size = input_ids.shape[0]
            max_new_tokens = 10

            # here we force to not stop at eos and go until max-length
            model.generation_config.eos_token_id = model.config.get_text_config().eos_token_id = -1
            generation_kwargs = {
                "max_new_tokens": max_new_tokens,
                "cache_implementation": "static",
                "return_dict_in_generate": True,  # Required to return `past_key_values`
            }

            inputs_embeds = model.get_input_embeddings()(input_ids)
            outputs = model.generate(inputs_embeds=inputs_embeds, **generation_kwargs, **inputs_dict)

            # we should get `max_length - 1` in shape, not `max_length - embeds_length`.
            # -1 because the last generated token isn't yet in the cache.
            text_config = model.config.get_text_config()
            max_length = max_new_tokens + inputs_embeds.shape[1] - 1
            self.assertIsInstance(outputs.past_key_values, StaticCache)
            self._check_past_key_values_for_generate(batch_size, outputs.past_key_values, max_length, text_config)

    @pytest.mark.generate
    def test_generate_continue_from_past_key_values(self):
        # Tests that we can continue generating from past key values, returned from a previous `generate` call
        for model_class in self.all_generative_model_classes:
            if any(model_name in model_class.__name__.lower() for model_name in ["imagegpt", "mllama"]):
                self.skipTest(reason="Won't fix: old model with unique inputs/caches/other")
            if any(model_name in model_class.__name__.lower() for model_name in ["umt5"]):
                self.skipTest(reason="TODO: needs modeling or test input preparation fixes for compatibility")

            # Set seed for deterministic test - ensures reproducible model initialization and inputs
            set_seed(42)
            config, inputs = self.model_tester.prepare_config_and_inputs_for_common()

            if not hasattr(config.get_text_config(), "use_cache"):
                self.skipTest(reason=f"{model_class.__name__} doesn't support caching")

            # Let's make it always:
            # 1. use cache (for obvious reasons)
            # 2. generate to max length (which can be achieved by setting the eos token to an invalid value), which
            #    would make the test flaky (e.g. EOS is generated on iteration 1 on both generations, but the
            #    continuation would force it to generate beyond an EOS token)
            # 3. ignore `token_type_ids` for simplicity
            # 4. ignore `forced_eos_token_id`, which requires further manipulation of the continuation inputs and is
            #    active by default on some models
            # 5. ignore `encoder_no_repeat_ngram_size`, which is set by default in some encoder-decoder models. When
            #    we use their decoder as a stand-alone model, `encoder_no_repeat_ngram_size` actually prevents
            #    repetition exclusively from the prompt. This test relies on comparing one call vs 2 calls
            #    with cache, what is considered a prompt is different in the two cases.

            if "token_type_ids" in inputs:
                del inputs["token_type_ids"]

            # Ensure left padding in the mask because otherwise position ids will
            # not be consecutive. Randomly mask leftmost tokens
            if (
                (attention_mask := inputs.get("attention_mask")) is not None
                and attention_mask.ndim == 2
                and 0 in attention_mask[:, -1]
            ):
                attention_mask = torch.ones_like(attention_mask)
                attention_mask[0, :1] = 0
                attention_mask[1:, :2] = 0
                inputs["attention_mask"] = attention_mask

            model = model_class(config).to(torch_device)
            model.eval()

            # If "past_key_values" is not returned, skip the test (e.g. RWKV uses a different cache name and format)
            outputs = model(**inputs)
            if "past_key_values" not in outputs:
                self.skipTest(reason="This model doesn't return `past_key_values`")

            generate_kwargs = {
                "pad_token_id": -1,
                "eos_token_id": -1,
                "forced_eos_token_id": None,
                "encoder_no_repeat_ngram_size": 0,
                "use_cache": True,
                "do_sample": False,
                "return_dict_in_generate": True,
                "output_scores": True,
            }

            # Traditional way of generating text, with `return_dict_in_generate` to return the past key values
            outputs = model.generate(**inputs, **generate_kwargs, max_new_tokens=4)

            # Let's generate again, but passing the past key values in between (3 + 1 = 4 tokens). Note that the
            # inputs may need to be tweaked across `generate` calls (like the attention mask).
            outputs_cached = model.generate(**inputs, **generate_kwargs, max_new_tokens=3)

            # Continue from the tokens generated above, preparing the inputs accordingly
            inputs["past_key_values"] = outputs_cached.past_key_values
            new_attention_len = outputs_cached.sequences.shape[-1]
            if config.is_encoder_decoder:
                inputs["decoder_input_ids"] = outputs_cached.sequences
                if "decoder_attention_mask" in inputs:
                    inputs["decoder_attention_mask"] = torch.nn.functional.pad(
                        inputs["decoder_attention_mask"],
                        (0, new_attention_len - inputs["decoder_attention_mask"].shape[1]),
                        mode="constant",
                        value=1,
                    )
            else:
                inputs["input_ids"] = outputs_cached.sequences
                if "attention_mask" in inputs:
                    inputs["attention_mask"] = torch.nn.functional.pad(
                        inputs["attention_mask"],
                        (0, new_attention_len - inputs["attention_mask"].shape[1]),
                        mode="constant",
                        value=1,
                    )
            # Pop multimodal data since they are already cached and we'll raise an error
            # if there are multimodal data which don't belong anywhere inside `text_tokens`
            keys_to_pop = []
            for key in inputs:
                if (
                    "pixel" in key
                    or key in ["image_patches", "input_feature", "input_features", "feature_attention_mask"]
                ) and key != model.main_input_name:
                    keys_to_pop.append(key)
            for key in keys_to_pop:
                inputs.pop(key)

            first_caches_scores = outputs_cached.scores
            outputs_cached = model.generate(**inputs, **generate_kwargs, max_new_tokens=1)
            full_cached_scores = first_caches_scores + outputs_cached.scores
            outputs_cached.scores = full_cached_scores

            # The two sets of generated text and past kv should be equal to each other
            if is_moe_model(config):
                atol = rtol = 1e-3
            else:
                atol = rtol = 1e-5
            assert_similar_generate_outputs(outputs, outputs_cached, atol=atol, rtol=rtol)
            self._check_caches_are_equal(outputs.past_key_values, outputs_cached.past_key_values)

    @pytest.mark.generate
    def test_generate_continue_from_inputs_embeds(self):
        """Tests that we can continue generation from `inputs_embeds` and past key values returned from a previous `generate` call."""
        for model_class in self.all_generative_model_classes:
            if any(model_name in model_class.__name__.lower() for model_name in ["imagegpt"]):
                self.skipTest(reason="Won't fix: old model with unique inputs/caches/other")
            if any(model_name in model_class.__name__.lower() for model_name in ["umt5"]):
                self.skipTest(reason="TODO: needs modeling or test input preparation fixes for compatibility")

            config, inputs_dict = self.prepare_config_and_inputs_for_generate()

            if "token_type_ids" in inputs_dict:
                del inputs_dict["token_type_ids"]

            if config.is_encoder_decoder:
                self.skipTest(reason="This model is encoder-decoder")
            # TODO (joao, raushan): the correct line below is `if not hasattr(config.get_text_config(), "use_cache")`,
            # but it breaks a few models. Fix and then apply `has_similar_generate_outputs` pattern
            if not hasattr(config, "use_cache"):
                self.skipTest(reason=f"{model_class.__name__} doesn't support caching")

            model = model_class(config).to(torch_device).eval()

            if "inputs_embeds" not in inspect.signature(model.prepare_inputs_for_generation).parameters:
                self.skipTest(reason="This model does not support `inputs_embeds` in generation")

            # If "past_key_values" is not returned, skip the test (e.g. RWKV uses a different cache name and format)
            outputs = model(**inputs_dict)
            if "past_key_values" not in outputs:
                self.skipTest(reason="This model doesn't return `past_key_values`")

            input_ids = inputs_dict.pop("input_ids")

            model.generation_config.pad_token_id = model.generation_config.eos_token_id = -1
            model.generation_config.forced_eos_token_id = None
            model.config.is_decoder = True
            model.generation_config.use_cache = True

            generation_kwargs = {
                "return_dict_in_generate": True,
                "do_sample": False,
            }

            # Traditional way of generating text, with `return_dict_in_generate` to return the past key values.
            inputs_embeds = model.get_input_embeddings()(input_ids)
            outputs = model.generate(inputs_embeds=inputs_embeds, max_new_tokens=4, **generation_kwargs)

            # Let's generate again, but passing the past key values in between (3 + 1 = 4 tokens)
            initial_output = model.generate(inputs_embeds=inputs_embeds, max_new_tokens=3, **generation_kwargs)
            continued_embeds = torch.cat(
                [inputs_embeds, model.get_input_embeddings()(initial_output.sequences)], dim=1
            )
            cached_output = model.generate(
                inputs_embeds=continued_embeds,
                max_new_tokens=1,
                past_key_values=initial_output.past_key_values,
                **generation_kwargs,
            )

            # Combine the (3 + 1) generated tokens and verify it matches with full generation.
            combined_output_sequences = torch.concat([initial_output.sequences, cached_output.sequences], axis=1)
            self.assertListEqual(outputs.sequences.tolist(), combined_output_sequences.tolist())
            # The two sets of past kv should be equal to each other
            self._check_caches_are_equal(outputs.past_key_values, cached_output.past_key_values)

    @pytest.mark.generate
    def test_generate_with_static_cache(self):
        """
        Tests that generating with static cache give almost same results as with dynamic cache, and the output cache
        has the expected shapes
        """
        for model_class in self.all_generative_model_classes:
            # Here, we should ideally not skip any model, and test them all. However, some old models cannot correctly
            # use a static cache because they don't create the causal masks correctly.
            # TODO: cyril -> relax this by adding a `_support_static_cache` attribute
            if not model_class._can_compile_fullgraph:
                self.skipTest(reason="This model does not support the static cache format")

            # Set seed for deterministic test - ensures reproducible model initialization and inputs
            set_seed(42)
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()
            set_config_for_less_flaky_test(config)
            main_input = inputs_dict[model_class.main_input_name]

            if config.is_encoder_decoder:
                self.skipTest(reason="This model is encoder-decoder and has Encoder-Decoder Cache")

            config.is_decoder = True
            batch_size = main_input.shape[0]
            seq_length = self.model_tester.seq_length
            max_new_tokens = 20

            for dtype in (torch.float32, torch.float16):
                model = model_class(copy.deepcopy(config)).to(torch_device).to(dtype).eval()
                inputs_dict = {
                    k: v.to(dtype) if isinstance(v, torch.Tensor) and torch.is_floating_point(v) else v
                    for k, v in inputs_dict.items()
                }
                set_model_for_less_flaky_test(model)

                generation_kwargs = {
                    "max_new_tokens": max_new_tokens,
                    "return_dict_in_generate": True,  # Required to return `past_key_values`
                    "output_scores": True,
                    "use_cache": True,
                }

                static_cache_generation = model.generate(
                    **generation_kwargs, **inputs_dict, cache_implementation="static"
                )

                # Check 1: The cache shapes must match the expected shapes
                text_config = model.config.get_text_config()
                max_cache_len = seq_length + max_new_tokens - 1  # cache len = gen len - 1, the last token has no cache
                self.assertTrue(isinstance(static_cache_generation.past_key_values, StaticCache))
                self._check_past_key_values_for_generate(
                    batch_size, static_cache_generation.past_key_values, max_cache_len, text_config
                )

                # Check 2: The outputs must be similar to the case with dynamic cache
                dynamic_cache_generation = model.generate(**generation_kwargs, **inputs_dict)
                if is_moe_model(config):
                    atol = rtol = 1e-3
                else:
                    atol = rtol = 1e-5
                assert_similar_generate_outputs(
                    dynamic_cache_generation, static_cache_generation, atol=atol, rtol=rtol
                )

    @require_optimum_quanto
    @pytest.mark.generate
    def test_generate_with_quant_cache(self):
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()

            if config.is_encoder_decoder or not model_class._supports_default_dynamic_cache():
                self.skipTest(reason="This model does not support the quantized cache format")

            config.is_decoder = True
            model = model_class(config).to(torch_device).eval()
            generation_kwargs = {
                "max_new_tokens": 5,
                "cache_implementation": "quantized",
                # careful with group size, should be divisor of model's hidden size
                "cache_config": {"backend": "quanto", "nbits": 2, "q_group_size": 8, "residual_length": 128},
                "return_dict_in_generate": True,  # Required to return `past_key_values`
                "use_cache": True,
            }

            results = model.generate(**generation_kwargs, **inputs_dict)
            self.assertTrue(all(isinstance(layer, QuantoQuantizedLayer) for layer in results.past_key_values.layers))

            # passing past key values of different type should raise Error
            with self.assertRaises(ValueError):
                model.generate(past_key_valyes=DynamicCache(config=model.config), **generation_kwargs, **inputs_dict)

            # setting incorrect cache_config args should raise an Error, i.e. nbits=60 does not make sense
            generation_kwargs["cache_config"] = {"nbits": 60, "q_group_size": 8, "residual_length": 128}
            with self.assertRaises(ValueError):
                model.generate(**generation_kwargs, **inputs_dict)

    @pytest.mark.generate
    @pytest.mark.torch_compile_test
    @require_torch_greater_or_equal("2.6")  # Uses torch.compiler.set_stance
    def test_generate_compile_model_forward_fullgraph(self):
        """
        Tests that `.generate` is compatible with torch.compile, keeping the same results. Also confirms that
        `.forward` called from `.generate` sees no graph breaks or recompilations when compiled.

        ⚠️ Runs two sequential generations to ensure the cache doesn't get stuck after the first compiled run! ⚠️
        """
        for model_class in self.all_generative_model_classes:
            # 1. Test exclusion criteria
            if not model_class._can_compile_fullgraph:
                self.skipTest("This model doesn't support compilation without graph breaks")

            # 2. Prepares two sets of inputs
            config, inputs_dict = self.prepare_config_and_inputs_for_generate(batch_size=4)
            set_config_for_less_flaky_test(config)
            model = model_class(config).to(torch_device)
            set_model_for_less_flaky_test(model)
            model.eval()  # otherwise `self.training` is `True` -- this flag is used at attn mask creation time

            # Some composite models have a custom generate and will call an inner model's generate -> that inner model
            # is the one that gets compiled.
            # (Note for the future: if BLIP starts causing problems, let's stop testing it)
            if "blip" in model.__class__.__name__.lower():
                model_to_be_compiled = model.language_model
            else:
                model_to_be_compiled = model

            # creates two sets of *different* inputs with the same shape
            main_input = inputs_dict[model.main_input_name].to(torch_device)
            half_batch_size = main_input.shape[0] // 2
            input_1 = {}
            input_2 = {}
            for key, value in inputs_dict.items():
                if isinstance(value, torch.Tensor):
                    input_1[key] = value[:half_batch_size, :].to(torch_device)
                    input_2[key] = value[half_batch_size : half_batch_size * 2, :].to(torch_device)
                else:
                    input_1[key] = value
                    input_2[key] = value
            model_input_sets = [input_1, input_2]
            self.assertTrue(
                model_input_sets[0][model.main_input_name].shape == model_input_sets[1][model.main_input_name].shape
            )

            # 3. compilation-specific setup and generation parameterization
            torch.compiler.reset()  # prevent cached compilation from being used in the test
            has_defined_cache_implementation = model.generation_config.cache_implementation is not None
            compile_config = CompileConfig(fullgraph=True, dynamic=False)  # Error out on dynamic shapes
            compile_config._compile_all_devices = True  # force compilation (e.g. fast CI, CPU)

            generation_kwargs = {
                "use_cache": True,
                "do_sample": False,
                "max_new_tokens": 5,
                "return_dict_in_generate": True,
                "output_scores": True,
                "compile_config": compile_config,
            }

            # 4. get eager + dynamic cache results for future comparison
            dynamic_outputs = []
            # Ignores all `torch.compile` usage, useful to test models that that have non-default compilable caches
            # (who would have used compilation in this section)
            with torch.compiler.set_stance("force_eager"):
                for model_inputs in model_input_sets:
                    gen_out = model.generate(**model_inputs, **generation_kwargs)
                    dynamic_outputs.append(gen_out)
                    # sanity checks for the default cache implementation
                    if not has_defined_cache_implementation:
                        decoder_cache = (
                            gen_out.past_key_values.self_attention_cache
                            if config.is_encoder_decoder
                            else gen_out.past_key_values
                        )
                        self.assertTrue(isinstance(decoder_cache, DynamicCache))
                        self.assertFalse(decoder_cache.is_compileable)
                        # our auto compile should NOT have been called
                        self.assertFalse(hasattr(model_to_be_compiled, "_compiled_call"))

            # 5. get compiled results -- relies on the automatic compilation triggered by specific compilable caches
            if not has_defined_cache_implementation:
                generation_kwargs["cache_implementation"] = "static"

            compiled_outputs = []
            # Uses a context manager to catch recompilation logs. If there is any recompilation, this test fails.
            # Try/Finally is used to ensure that the log options are reset even if an error is raised.
            try:
                torch._logging.set_logs(recompiles_verbose=True)
                logger = logging.get_logger("torch._dynamo.guards")
                with CaptureLogger(logger) as cl:
                    for model_inputs in model_input_sets:
                        # with torch.compiler.set_stance("fail_on_recompile"):
                        gen_out = model.generate(**model_inputs, **generation_kwargs)
                        compiled_outputs.append(gen_out)
                        # sanity checks
                        decoder_cache = (
                            gen_out.past_key_values.self_attention_cache
                            if config.is_encoder_decoder
                            else gen_out.past_key_values
                        )
                        self.assertFalse(isinstance(decoder_cache, DynamicCache))
                        self.assertTrue(decoder_cache.is_compileable)
                        # our auto compile should have been called
                        self.assertTrue(hasattr(model_to_be_compiled, "_compiled_call"))
            finally:
                torch._logging.set_logs()

            # Compilation of sliding layers necessarily has recompiles with `dynamic=False` - however this test
            # still checks that `fullgraph=True` is supported in this case, as compilation with `dynamic=None`
            # is the default and does not actually lead to too many recompiles
            has_sliding_layers = any(decoder_cache.is_sliding)
            has_recompilation = "Recompiling" in cl.out or ("guard" in cl.out and "failure" in cl.out)
            if not has_sliding_layers and has_recompilation:
                raise RuntimeError(
                    f"`torch.compile` recompiled part of the forward pass in {model.__class__.__name__}. "
                    "See the test logs for more details."
                )

            if is_moe_model(config):
                atol = rtol = 1e-3
            else:
                atol = rtol = 1e-5
            for dynamic_result, compiled_result in zip(dynamic_outputs, compiled_outputs):
                assert_similar_generate_outputs(dynamic_result, compiled_result, atol=atol, rtol=rtol)

    @pytest.mark.generate
    def test_generate_compilation_all_outputs(self):
        """
        Tests that all optional outputs are behaving as expected when compilation is triggered.
        In essence, it's the same as `test_greedy_generate_dict_outputs`, but with automatic compilation triggered.
        """
        for model_class in self.all_generative_model_classes:
            # Here, we should ideally not skip any model, and test them all. However, some old models cannot correctly
            # use a static cache because they don't create the causal masks correctly.
            # TODO: cyril -> relax this by adding a `_support_static_cache` attribute
            if not model_class._can_compile_fullgraph:
                self.skipTest(reason="This model does not support the static cache format")

            config, inputs_dict = self.prepare_config_and_inputs_for_generate()
            if self.has_attentions:
                config._attn_implementation = "eager"  # can't output attentions otherwise
            model = model_class(config).to(torch_device).eval()

            # compilation-specific setup
            torch.compiler.reset()  # prevent cached compilation from being used in the test
            has_defined_cache_implementation = model.generation_config.cache_implementation is not None

            # BLIP is the only exception with custom generate which call `self.lm.generate()`
            # We should avoid such calls in all subsequent multimodal models and try to make `generate()`
            # compatible with multimodality
            compile_config = CompileConfig()
            compile_config._compile_all_devices = True
            if "blip" in model.__class__.__name__.lower():
                model.language_model.generation_config.compile_config = compile_config
                if not has_defined_cache_implementation:
                    model.language_model.generation_config.cache_implementation = "static"
            else:
                # force compilation (e.g. fast CI, CPU)
                model.generation_config.compile_config = compile_config
                if not has_defined_cache_implementation:
                    model.generation_config.cache_implementation = "static"

            logits_processor_kwargs = self._get_logits_processor_kwargs(do_sample=False, config=model.config)
            output_generate = model.generate(
                do_sample=False,
                num_beams=1,
                max_new_tokens=self.max_new_tokens,
                min_new_tokens=self.max_new_tokens,
                output_attentions=True,
                output_hidden_states=True,
                output_scores=True,
                output_logits=True,
                return_dict_in_generate=True,
                use_cache=True,
                **logits_processor_kwargs,
                **inputs_dict,
            )

            if "blip" in model.__class__.__name__.lower():
                self.assertTrue(hasattr(model.language_model, "_compiled_call"))
            else:
                self.assertTrue(hasattr(model, "_compiled_call"))  # our auto compile should have been called

            if model.config.is_encoder_decoder:
                self.assertTrue(output_generate.sequences.shape[1] == self.max_new_tokens + 1)
                self.assertIsInstance(output_generate, GenerateEncoderDecoderOutput)
            else:
                self.assertTrue(
                    output_generate.sequences.shape[1] == self.max_new_tokens + inputs_dict["input_ids"].shape[1]
                )
                self.assertIsInstance(output_generate, GenerateDecoderOnlyOutput)

            self._check_generate_outputs(output_generate, model.config, use_cache=True)

    @pytest.mark.generate
    def test_generate_methods_with_logits_to_keep(self):
        for model_class in self.all_generative_model_classes:
            if "logits_to_keep" not in set(inspect.signature(model_class.forward).parameters.keys()):
                self.skipTest(reason="This model does not support `logits_to_keep` argument.")

            config, inputs_dict = self.prepare_config_and_inputs_for_generate()
            config.is_decoder = True

            model = model_class(config).to(torch_device).eval()
            model.generation_config.use_cache = True
            # All generation methods (except assisted decoding) rely on always extracting the last token logits of the
            # full logits matrix, so testing out only greedy search and assisted decoding is enough (if it works,
            # other methods will work as well)
            generation_kwargs = {
                "max_new_tokens": 10,
                "do_sample": False,
            }

            # Setting logits_to_keep at 0 keeps all logits (old behavior)
            with_all_logits = model.generate(**generation_kwargs, **inputs_dict, logits_to_keep=0)
            # By default, logits_to_keep is automatically set to 1 if not provided (new behavior)
            without_all_logits = model.generate(**inputs_dict, **generation_kwargs)
            self.assertEqual(with_all_logits.tolist(), without_all_logits.tolist())

    @pytest.mark.generate
    def test_inherits_generation_mixin(self):
        """
        Tests that the model class directly inherits `GenerationMixin`, as opposed to relying on `PreTrainedModel`
        to inherit it.
        """
        for model_class in self.all_generative_model_classes:
            self.assertTrue("GenerationMixin" in str(model_class.__bases__))

    @pytest.mark.generate
    def test_prepare_inputs_for_generation_kwargs_forwards(self, **extra_kwargs):
        """Tests that prepare_inputs_for_generation forwards arbitrary kwargs."""
        for model_class in self.all_generative_model_classes:
            config, _ = self.prepare_config_and_inputs_for_generate()

            model = model_class(config).to(torch_device).eval()

            input_ids = torch.tensor([[1, 2, 3], [4, 5, 6]]).to(torch_device)

            input_args = {
                "input_ids": input_ids,
                "position_ids": torch.tensor([[0, 1, 2], [0, 1, 2]]).to(torch_device),
            }
            arbitrary_kwargs = {
                "output_attentions": True,
                "output_hidden_states": True,
                "custom_arg": "test_value",
                "numeric_arg": 42,
            }

            model_inputs = model.prepare_inputs_for_generation(**input_args, **arbitrary_kwargs, **extra_kwargs)

            # Verify that input_ids has proper name
            if config.is_encoder_decoder:
                self.assertTrue("decoder_input_ids" in model_inputs)
            else:
                self.assertTrue("input_ids" in model_inputs)

            # Verify that arbitrary kwargs are forwarded
            for key, value in arbitrary_kwargs.items():
                self.assertTrue(key in model_inputs)
                self.assertTrue(model_inputs[key] == value)

    def _test_attention_implementation(self, attn_implementation):
        """
        Compares the output of generate with the eager attention implementation against other implementations.
        NOTE: despite the test logic being the same, different implementations actually need different decorators, hence
        this separate function.
        """
        max_new_tokens = 3
        support_flag = {
            "sdpa": "_supports_sdpa",
            "flash_attention_2": "_supports_flash_attn",
            "flash_attention_3": "_supports_flash_attn",
            "flash_attention_4": "_supports_flash_attn",
        }

        for model_class in self.all_generative_model_classes:
            if attn_implementation != "eager" and not getattr(model_class, support_flag[attn_implementation]):
                self.skipTest(f"{model_class.__name__} does not support `attn_implementation={attn_implementation}`")

            config, original_inputs_dict = self.prepare_config_and_inputs_for_generate()
            inputs_dict = {}
            for input_name, input_data in original_inputs_dict.items():
                if isinstance(input_data, torch.Tensor) and input_data.dtype in [torch.float32, torch.bfloat16]:
                    inputs_dict[input_name] = input_data.to(torch.float16)
                else:
                    inputs_dict[input_name] = input_data
            main_input = inputs_dict[model_class.main_input_name]

            # FA doesn't accept masking in the middle of the sequence for now. We usually generate right-padded
            # attention masks at test time and, with generate, the mask will be appended with 1s on the right,
            # resulting in a mask with holes (not supported properly by FA).
            if is_flash_attention_requested(requested_attention_implementation=attn_implementation):
                for input_name in ("attention_mask", "decoder_attention_mask", "encoder_attention_mask"):
                    if input_name in inputs_dict:
                        inputs_dict[input_name] = torch.ones_like(inputs_dict[input_name])

            # make sure that all models have enough positions for generation
            if hasattr(config, "max_position_embeddings"):
                config.max_position_embeddings = max_new_tokens + main_input.shape[1] + 1

            set_config_for_less_flaky_test(config)
            model = model_class(config)

            # If not all sub-models support flex, skip the test. We could potentially set not supported backbones
            # to "eager" attention, leaving it for future updates on multimodality tests
            sub_models_supporting_attn = [
                getattr(module, support_flag[attn_implementation])
                for name, module in model.named_modules()
                if isinstance(module, PreTrainedModel) and name != ""
            ]
            if not all(sub_models_supporting_attn) and len(sub_models_supporting_attn) > 0:
                self.skipTest(
                    f"One of {model_class.__name__}'s backbones does not support `attn_implementation={attn_implementation}`"
                )

            with tempfile.TemporaryDirectory() as tmpdirname:
                model.save_pretrained(tmpdirname)
                del model
                gc.collect()

                generate_kwargs = {
                    "max_new_tokens": max_new_tokens,
                    "do_sample": False,
                    "return_dict_in_generate": True,
                    "output_scores": True,
                    "use_cache": True,
                }

                model_eager = model_class.from_pretrained(
                    tmpdirname,
                    dtype=torch.float16,
                    attn_implementation="eager",
                ).to(torch_device)
                set_model_for_less_flaky_test(model_eager)
                res_eager = model_eager.generate(**inputs_dict, **generate_kwargs)
                del model_eager
                gc.collect()

                model_attn = model_class.from_pretrained(
                    tmpdirname,
                    dtype=torch.float16,
                    attn_implementation=attn_implementation,
                ).to(torch_device)
                set_model_for_less_flaky_test(model_attn)
                res_attn = model_attn.generate(**inputs_dict, **generate_kwargs)
                del model_attn
                gc.collect()

                assert_similar_generate_outputs(res_eager, res_attn, atol=1e-3, rtol=1e-3)

    @pytest.mark.generate
    @slow
    def test_eager_matches_sdpa_generate(self):
        """Tests that generate has equivalent outputs with SDPA and eager attention implementations."""
        self._test_attention_implementation("sdpa")

    @pytest.mark.flash_attn_test
    @require_flash_attn
    @require_torch_accelerator
    @slow
    def test_eager_matches_fa2_generate(self):
        """Tests that generate has equivalent outputs with FA2 and eager attention implementations."""
        self._test_attention_implementation("flash_attention_2")

    @pytest.mark.flash_attn_3_test
    @require_flash_attn_3
    @require_torch_gpu
    @slow
    def test_eager_matches_fa3_generate(self):
        """Tests that generate has equivalent outputs with FA3 and eager attention implementations."""
        self._test_attention_implementation("flash_attention_3")

    @pytest.mark.flash_attn_4_test
    @require_flash_attn_4
    @require_torch_gpu
    @slow
    def test_eager_matches_fa4_generate(self):
        """Tests that generate has equivalent outputs with FA4 and eager attention implementations."""
        self._test_attention_implementation("flash_attention_4")

    @require_flash_attn
    @require_torch_accelerator
    @pytest.mark.flash_attn_test
    def test_flash_attention_2_continue_generate_with_position_ids(self):
        """
        Tests whether flash attention can continue its generation from given position ids.

        NOTE: This serves as regression check as we had instances where flash attention entered the varlen
        path here. It should now always enter the base `flash_fn`.
        """

        max_new_tokens = 2
        for model_class in self.all_generative_model_classes:
            if not model_class._supports_flash_attn:
                self.skipTest(f"{model_class.__name__} does not support Flash Attention.")

            config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
            if config.is_encoder_decoder:
                self.skipTest("Model is an encoder-decoder")

            if not hasattr(config.get_text_config(), "use_cache"):
                self.skipTest(f"{model_class.__name__} doesn't support caching")

            if "input_ids" not in inputs_dict or inputs_dict["input_ids"].ndim != 2:
                self.skipTest("Model dummy inputs should contain text input ids")

            # make sure that all models have enough positions for generation
            dummy_input_ids = inputs_dict["input_ids"]
            if hasattr(config, "max_position_embeddings"):
                config.max_position_embeddings = max_new_tokens + dummy_input_ids.shape[1] + 1

            model = model_class(config)
            if not all(
                getattr(submodel, "_supports_flash_attn")
                for submodel in model.modules()
                if isinstance(submodel, PreTrainedModel)
            ):
                self.skipTest(f"At least some parts of {model_class.__name__} don't support flash attention")

            if "position_ids" not in inspect.signature(model.forward).parameters:
                self.skipTest("Model does not support position_ids")

            with tempfile.TemporaryDirectory() as tmpdirname:
                model.save_pretrained(tmpdirname)
                model = (
                    model_class.from_pretrained(
                        tmpdirname,
                        dtype=torch.bfloat16,
                        attn_implementation="flash_attention_2",
                    )
                    .to(torch_device)
                    .eval()
                )

                # Drop all keys except for `input_ids`. Hard to manipulate with multimodals etc
                dummy_input_ids = inputs_dict["input_ids"]
                dummy_position_ids = torch.arange(dummy_input_ids.shape[1], device=torch_device)
                dummy_position_ids = dummy_position_ids.unsqueeze(0).repeat(dummy_input_ids.shape[0], 1)

                # Store cache for the input prompt
                output = model(dummy_input_ids, position_ids=dummy_position_ids, use_cache=True)
                if "past_key_values" not in output:
                    self.skipTest("This model doesn't return `past_key_values`")

                # create new input_ids and position_ids to continue generation re-using the cache
                new_input_ids = output.logits[:, -1, :].float().argmax(-1)[:, None]
                past_length = dummy_input_ids.shape[1]
                position_ids = torch.arange(past_length, past_length + new_input_ids.shape[1], device=torch_device)
                position_ids = position_ids.unsqueeze(0).repeat(new_input_ids.shape[0], 1)

                output = model(
                    input_ids=new_input_ids,
                    past_key_values=output.past_key_values,
                    position_ids=position_ids,
                    use_cache=True,
                )
                next_token_logits = output.logits[:, -1, :].float()

                generate_kwargs = {
                    "pad_token_id": -1,
                    "eos_token_id": -1,
                    "forced_eos_token_id": None,
                    "use_cache": True,
                    "do_sample": False,
                    "return_dict_in_generate": True,
                    "output_logits": True,
                    "max_new_tokens": max_new_tokens,
                }
                generation_out = model.generate(dummy_input_ids, **generate_kwargs)
                next_token_logits_from_generate = generation_out.logits[-1]

                # acceptable numerical instability
                tol = torch.finfo(torch.bfloat16).eps
                torch.testing.assert_close(next_token_logits_from_generate, next_token_logits, rtol=tol, atol=tol)

    def attention_mask_padding_matches_padding_free_with_position_ids(
        self, attn_implementation: str, fa_kwargs: bool = False
    ):
        """
        Tests that the given attention implementation can work with packed sequences and infers the mask
        from position ids. This test requires the model to use new attention mask API which handles packing.
        """
        if not self.has_attentions:
            self.skipTest(reason="Model architecture does not support attentions")

        max_new_tokens = 30
        support_flag = {
            "sdpa": "_supports_sdpa",
            "flash_attention_2": "_supports_flash_attn",
            "flash_attention_3": "_supports_flash_attn",
            "flash_attention_4": "_supports_flash_attn",
        }

        for model_class in self.all_generative_model_classes:
            if attn_implementation != "eager" and not getattr(model_class, support_flag[attn_implementation]):
                self.skipTest(f"{model_class.__name__} does not support {attn_implementation}")

            # can't infer if new attn mask API is supported by assume that only model with attention backend support it
            if not model_class._supports_attention_backend:
                self.skipTest(f"{model_class.__name__} does not support new attention mask API")

            if model_class._is_stateful:  # non-transformer models most probably have no packing support
                self.skipTest(f"{model_class.__name__} doesn't support packing!")

            config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
            if config.is_encoder_decoder:
                self.skipTest("Model is an encoder-decoder")

            if "input_ids" not in inputs_dict or inputs_dict["input_ids"].ndim != 2:
                self.skipTest("Model dummy inputs should contain text input ids")

            if 0 not in inputs_dict.get("attention_mask", []) or "attention_mask" not in inputs_dict:
                self.skipTest("Model dummy inputs should contain padding in their attention mask")

            # make sure that all models have enough positions for generation
            dummy_input_ids = inputs_dict["input_ids"]
            if hasattr(config, "max_position_embeddings"):
                config.max_position_embeddings = max_new_tokens + dummy_input_ids.shape[1] + 1

            model = model_class(config)
            if attn_implementation != "eager":
                if not all(
                    getattr(submodel, support_flag[attn_implementation])
                    for submodel in model.modules()
                    if isinstance(submodel, PreTrainedModel)
                ):
                    self.skipTest(f"At least some parts of {model_class.__name__} don't support {attn_implementation}")

            if "position_ids" not in inspect.signature(model.forward).parameters:
                self.skipTest("Model does not support position_ids")

            if (not fa_kwargs) and "position_ids" not in inspect.signature(model.forward).parameters:
                continue  # this model doesn't accept position ids as input

            with tempfile.TemporaryDirectory() as tmpdirname:
                model.save_pretrained(tmpdirname)

                # Drop all keys except for the minimal set. Hard to manipulate with multimodals etc
                inputs_dict = {k: v for k, v in inputs_dict.items() if k in ["input_ids", "attention_mask"]}

                # Ensure left padding, to adapt for some models
                if 0 in inputs_dict["attention_mask"][:, -1]:
                    inputs_dict["attention_mask"] = inputs_dict["attention_mask"].flip(1)
                dummy_attention_mask = inputs_dict["attention_mask"]
                dummy_input_ids[~dummy_attention_mask.bool()] = config.get_text_config().pad_token_id

                # We need to prepare position ids according to the attention mask as we use it to extract embeddings that
                # rely on the correct position - naively increasing sequences do not suffice anymore atp. The solution here
                # calculates an increasing sequences for all 1s and puts 0s else.
                inputs_dict["position_ids"] = ((inputs_dict["attention_mask"] == 1).long().cumsum(dim=1) - 1) * (
                    inputs_dict["attention_mask"] == 1
                ).long()

                model = (
                    model_class.from_pretrained(
                        tmpdirname,
                        dtype=torch.bfloat16,
                        attn_implementation=attn_implementation,
                    )
                    .to(torch_device)
                    .eval()
                )

                if fa_kwargs:
                    # flatten
                    features = [
                        {"input_ids": i[a.bool()].tolist()} for i, a in zip(dummy_input_ids, dummy_attention_mask)
                    ]

                    # add position_ids + fa_kwargs
                    data_collator = DataCollatorWithFlattening(return_tensors="pt", return_flash_attn_kwargs=True)
                    batch = data_collator(features)
                    padfree_inputs_dict = {
                        k: t.to(torch_device) if torch.is_tensor(t) else t for k, t in batch.items()
                    }
                    padfree_inputs_dict.pop("labels", None)  # can lead to silent upcasts on logits
                else:
                    # create packed position_ids
                    position_ids = (
                        torch.cat([torch.arange(length) for length in dummy_attention_mask.sum(1).tolist()])
                        .long()
                        .unsqueeze(0)
                        .to(torch_device)
                    )
                    padfree_inputs_dict = {
                        "input_ids": dummy_input_ids[dummy_attention_mask.bool()].unsqueeze(0),
                        "position_ids": position_ids,
                    }

                # We need to do simple forward without cache in order to trigger packed SDPA/flex/eager attention path
                res_padded = model(**inputs_dict, use_cache=False)
                res_padfree = model(**padfree_inputs_dict, use_cache=False)

                logits_padded = res_padded.logits[dummy_attention_mask.bool()]
                logits_padfree = res_padfree.logits[0]

                # acceptable numerical instability
                tol = torch.finfo(torch.bfloat16).eps
                torch.testing.assert_close(logits_padded, logits_padfree, rtol=tol, atol=tol)

    def test_eager_padding_matches_padding_free_with_position_ids(self):
        self.attention_mask_padding_matches_padding_free_with_position_ids(attn_implementation="eager")

    def test_sdpa_padding_matches_padding_free_with_position_ids(self):
        self.attention_mask_padding_matches_padding_free_with_position_ids(attn_implementation="sdpa")

    @require_flash_attn
    @require_torch_accelerator
    @pytest.mark.flash_attn_test
    @slow
    def test_flash_attention_2_padding_matches_padding_free_with_position_ids(self):
        self.attention_mask_padding_matches_padding_free_with_position_ids(attn_implementation="flash_attention_2")

    @require_flash_attn
    @require_torch_accelerator
    @pytest.mark.flash_attn_test
    @slow
    def test_flash_attention_2_padding_matches_padding_free_with_position_ids_and_fa_kwargs(self):
        self.attention_mask_padding_matches_padding_free_with_position_ids(
            attn_implementation="flash_attention_2", fa_kwargs=True
        )

    @require_flash_attn_3
    @require_torch_gpu
    @pytest.mark.flash_attn_3_test
    @slow
    def test_flash_attention_3_padding_matches_padding_free_with_position_ids(self):
        self.attention_mask_padding_matches_padding_free_with_position_ids(attn_implementation="flash_attention_3")

    @require_flash_attn_3
    @require_torch_gpu
    @pytest.mark.flash_attn_3_test
    @slow
    def test_flash_attention_3_padding_matches_padding_free_with_position_ids_and_fa_kwargs(self):
        self.attention_mask_padding_matches_padding_free_with_position_ids(
            attn_implementation="flash_attention_3", fa_kwargs=True
        )

    @require_flash_attn_4
    @require_torch_gpu
    @pytest.mark.flash_attn_4_test
    @slow
    def test_flash_attention_4_padding_matches_padding_free_with_position_ids(self):
        self.attention_mask_padding_matches_padding_free_with_position_ids(attn_implementation="flash_attention_4")

    @require_flash_attn_4
    @require_torch_gpu
    @pytest.mark.flash_attn_4_test
    @slow
    def test_flash_attention_4_padding_matches_padding_free_with_position_ids_and_fa_kwargs(self):
        self.attention_mask_padding_matches_padding_free_with_position_ids(
            attn_implementation="flash_attention_4", fa_kwargs=True
        )

    def _get_custom_4d_mask_test_data(self):
        # Sequence in which all but the last token is the same
        input_ids = torch.tensor(
            [[10, 11, 12, 13], [10, 11, 12, 14], [10, 11, 12, 15]], device=torch_device, dtype=torch.int64
        )
        position_ids = torch.tensor([[0, 1, 2, 3]] * 3, device=torch_device, dtype=torch.int64)

        # Combining common prefix with the unique ending tokens:
        input_ids_shared_prefix = torch.cat([input_ids[0][:-1], input_ids[:, -1]]).unsqueeze(0)

        # Creating a 4D mask where each of the last 3 tokens do not attend to each other.
        mask_shared_prefix = torch.tensor(
            [
                [
                    [
                        [1, 0, 0, 0, 0, 0],
                        [1, 1, 0, 0, 0, 0],
                        [1, 1, 1, 0, 0, 0],
                        [1, 1, 1, 1, 0, 0],
                        [1, 1, 1, 0, 1, 0],
                        [1, 1, 1, 0, 0, 1],
                    ]
                ]
            ],
        )
        # inverting the attention mask
        mask_dtype = torch.float32
        min_dtype = torch.finfo(mask_dtype).min
        mask_shared_prefix = (mask_shared_prefix.eq(0.0)).to(dtype=mask_dtype, device=torch_device) * min_dtype

        # Creating a position_ids tensor. note the repeating figures in the end.
        position_ids_shared_prefix = torch.tensor([[0, 1, 2, 3, 3, 3]], device=torch_device, dtype=torch.int64)

        return input_ids, position_ids, input_ids_shared_prefix, mask_shared_prefix, position_ids_shared_prefix

    def test_custom_4d_attention_mask(self):
        if not self.has_attentions:
            self.skipTest(reason="Model architecture does not support attentions")

        for model_class in self.all_generative_model_classes:
            if not model_class._can_compile_fullgraph:
                self.skipTest(f"{model_class.__name__} is not guaranteed to work with custom 4D attention masks")
            config, _ = self.model_tester.prepare_config_and_inputs_for_common()
            set_config_for_less_flaky_test(config)
            if getattr(config, "sliding_window", 0) is not None and getattr(config, "sliding_window", 0) > 0:
                self.skipTest(f"{model_class.__name__} with sliding window attention is not supported by this test")
            model = model_class(config).to(device=torch_device, dtype=torch.float32).eval()
            set_model_for_less_flaky_test(model)
            if "position_ids" not in inspect.signature(model.forward).parameters:
                continue  # model doesn't accept position ids and probably has special way to model positions

            (
                input_ids,
                position_ids,
                input_ids_shared_prefix,
                mask_shared_prefix,
                position_ids_shared_prefix,
            ) = self._get_custom_4d_mask_test_data()

            logits = model.forward(input_ids, position_ids=position_ids).logits
            # logits.shape == torch.Size([3, 4, ...])

            logits_shared_prefix = model(
                input_ids_shared_prefix,
                attention_mask=mask_shared_prefix,
                position_ids=position_ids_shared_prefix,
            )[0]
            # logits_shared_prefix.shape == torch.Size([1, 6, ...])

            out_last_tokens = logits[:, -1, :]  # last tokens in each batch line
            out_shared_prefix_last_tokens = logits_shared_prefix[0, -3:, :]  # last three tokens

            # comparing softmax-normalized logits:
            normalized_0 = F.softmax(out_last_tokens, dim=-1)
            normalized_1 = F.softmax(out_shared_prefix_last_tokens, dim=-1)
            torch.testing.assert_close(normalized_0, normalized_1, rtol=1e-3, atol=1e-3)

    def test_forward_with_logits_to_keep(self):
        for model_class in self.all_generative_model_classes:
            if "logits_to_keep" not in set(inspect.signature(model_class.forward).parameters.keys()):
                self.skipTest(reason="This model does not support `logits_to_keep` argument.")

            config, inputs = self.model_tester.prepare_config_and_inputs_for_common()
            batch_size, sequence_length = inputs["input_ids"].shape[:2]
            vocab_size = config.get_text_config().vocab_size
            model = model_class(config).to(device=torch_device).eval()
            # some models have labels but `logits_to_keep` should not be used in train mode
            _ = inputs.pop("labels", None)

            # logits_to_keep=0 is a special case meaning "keep all logits"
            all_logits = model(**inputs, logits_to_keep=0).logits
            last_token_logits = model(**inputs, logits_to_keep=1).logits

            # Assert all shapes are correct
            self.assertEqual(tuple(all_logits.shape), (batch_size, sequence_length, vocab_size))
            self.assertEqual(tuple(last_token_logits.shape), (batch_size, 1, vocab_size))

            # Assert the last tokens are actually the same (except for the natural fluctuation due to order of FP ops)
            torch.testing.assert_close(all_logits[:, -1:, :], last_token_logits, rtol=1e-5, atol=1e-5)

    def test_generate_with_and_without_position_ids(self):
        ran_any_model = False
        for model_class in self.all_generative_model_classes:
            config, inputs_dict = self.prepare_config_and_inputs_for_generate()
            model = model_class(config).to(torch_device).eval()
            model_forward_args = inspect.signature(model.forward).parameters

            has_3d_rope_positions = any(
                hasattr(module, "get_rope_index")
                for module in (
                    model,
                    getattr(model, "model", None),
                    getattr(model, "language_model", None),
                    getattr(model, "text_model", None),
                )
            )
            if has_3d_rope_positions:
                continue

            if "position_ids" not in model_forward_args or "input_ids" not in inputs_dict:
                self.skipTest("This model doesn't use `position_ids`")

            if config.is_encoder_decoder:
                self.skipTest("This model doesn't prepare `position_ids` in generate")

            ran_any_model = True
            input_ids = inputs_dict["input_ids"]
            seq_length = input_ids.shape[1]
            # ensure left padding
            if "attention_mask" in inputs_dict and 0 in inputs_dict["attention_mask"][:, -1]:
                inputs_dict["attention_mask"] = inputs_dict["attention_mask"].flip(1)
            else:
                generation_config = copy.deepcopy(model.generation_config)
                model._prepare_special_tokens(generation_config)
                inputs_dict["attention_mask"] = model._prepare_attention_mask_for_generation(
                    input_ids, generation_config, model_kwargs={}
                )

            out_wo_positions = model.generate(**inputs_dict, max_new_tokens=5, use_cache=True, do_sample=False)

            # infer position ids from attn mask and generate again
            attention_mask = inputs_dict["attention_mask"]
            position_ids = attention_mask.long().cumsum(-1) - 1
            position_ids = position_ids.masked_fill(attention_mask == 0, 0)
            position_ids = position_ids[..., -seq_length:].view(-1, seq_length)

            out_w_positions = model.generate(
                **inputs_dict, position_ids=position_ids, max_new_tokens=5, use_cache=True, do_sample=False
            )

            # The two sets of generated sequences must match, if generate can infer position ids correctly
            # and can continue adding new ids to the already passed position ids
            self.assertListEqual(out_wo_positions.tolist(), out_w_positions.tolist())

        if not ran_any_model:
            self.skipTest(
                "All model classes in this test use 3D RoPE positions (`get_rope_index`), for which 2D custom "
                "`position_ids` may be accepted but are expected to produce invalid outputs."
            )

    def _check_generate_outputs(self, output, config, use_cache=False, num_return_sequences=1, num_beams=1):
        input_batch_size = int(output.sequences.shape[0] / num_return_sequences)
        internal_batch_size = (
            input_batch_size * num_beams if num_beams > 1 else input_batch_size * num_return_sequences
        )

        prompt_length = getattr(self.model_tester, "seq_length", None)
        prompt_length = getattr(self.model_tester, "encoder_seq_length", prompt_length)
        prompt_length = getattr(self.model_tester, "text_seq_length", prompt_length)

        config = config.text_config if hasattr(config, "text_config") else config

        generated_length = (
            output.sequences.shape[1] - 1 if config.is_encoder_decoder else output.sequences.shape[1] - prompt_length
        )

        cache = getattr(output, "past_key_values", None)
        decoder_past_key_values = cache.self_attention_cache if isinstance(cache, EncoderDecoderCache) else cache

        # in some models we subsample the sequence length in inner layers
        if hasattr(self.model_tester, "get_subsampled_output_lengths"):
            prompt_length = self.model_tester.get_subsampled_output_lengths(prompt_length)

        # scores
        self._check_scores(
            batch_size=internal_batch_size, scores=output.scores, generated_length=generated_length, config=config
        )

        # unprocessed logits
        self._check_logits(batch_size=internal_batch_size, logits=output.logits, config=config)

        # Attentions
        if self.has_attentions:
            if config.is_encoder_decoder:
                # encoder
                self._check_encoder_attention_for_generate(
                    attentions=output.encoder_attentions,
                    batch_size=input_batch_size,
                    config=config,
                    prompt_length=prompt_length,
                )
                # decoder
                self._check_attentions_for_generate(
                    batch_size=internal_batch_size,
                    attentions=output.decoder_attentions,
                    prompt_length=1,  # the BOS token
                    output_length=output.sequences.shape[1],
                    config=config,
                    decoder_past_key_values=decoder_past_key_values,
                )
            else:
                self._check_attentions_for_generate(
                    batch_size=internal_batch_size,
                    attentions=output.attentions,
                    prompt_length=prompt_length,
                    output_length=output.sequences.shape[1],
                    config=config,
                    decoder_past_key_values=decoder_past_key_values,
                )

        # Hidden States
        if config.is_encoder_decoder:
            # encoder
            self._check_encoder_hidden_states_for_generate(
                hidden_states=output.encoder_hidden_states,
                batch_size=input_batch_size,
                config=config,
                prompt_length=prompt_length,
            )
            # decoder
            self._check_hidden_states_for_generate(
                batch_size=internal_batch_size,
                hidden_states=output.decoder_hidden_states,
                prompt_length=1,  # the BOS token
                output_length=output.sequences.shape[1],
                config=config,
                use_cache=use_cache,
            )
        else:
            self._check_hidden_states_for_generate(
                batch_size=internal_batch_size,
                hidden_states=output.hidden_states,
                prompt_length=prompt_length,
                output_length=output.sequences.shape[1],
                config=config,
                use_cache=use_cache,
            )

        # Check the cache shape
        if use_cache:
            cache_length = output.sequences.shape[1] - 1
            self._check_past_key_values_for_generate(
                batch_size=internal_batch_size,
                past_key_values=cache,
                seq_length=cache_length,
                config=config,
            )
        # xlnet has a weird list cache, which is returned even with `use_cache=False`...
        elif "xlnet" not in config.__class__.__name__.lower():
            self.assertTrue(cache is None)

    def _check_scores(self, batch_size, scores, generated_length, config):
        vocab_size = config.get_text_config(decoder=True).vocab_size
        expected_shape = (batch_size, vocab_size)
        self.assertIsInstance(scores, tuple)
        self.assertEqual(len(scores), generated_length)
        self.assertListEqual([iter_scores.shape for iter_scores in scores], [expected_shape] * len(scores))

    def _check_logits(self, batch_size, logits, config):
        vocab_size = config.get_text_config(decoder=True).vocab_size
        self.assertIsInstance(logits, tuple)
        self.assertListEqual([iter_logits.shape[0] for iter_logits in logits], [batch_size] * len(logits))
        # vocabulary difference equal to one (imagegptmodel?) or zero (all other models)
        vocab_diff = vocab_size - logits[0].shape[-1]
        self.assertTrue(vocab_diff in [0, 1])
        self.assertListEqual([vocab_size - score.shape[-1] for score in logits], [vocab_diff] * len(logits))

    def _check_attentions_for_generate(
        self, batch_size, attentions, prompt_length, output_length, config, decoder_past_key_values
    ):
        self.assertIsInstance(attentions, tuple)
        self.assertListEqual(
            [isinstance(iter_attentions, tuple) for iter_attentions in attentions], [True] * len(attentions)
        )
        self.assertEqual(len(attentions), (output_length - prompt_length))

        use_cache = decoder_past_key_values is not None
        has_static_cache = isinstance(decoder_past_key_values, StaticCache)

        # When `output_attentions=True`, each iteration of generate appends the attentions corresponding to the new
        # token(s)
        # NOTE: `StaticCache` may have different lengths on different layers, if this test starts failing add more
        # elaborate checks
        for generated_length, iter_attentions in enumerate(attentions):
            # regardless of using cache, the first forward pass will have the full prompt as input
            if use_cache and generated_length > 0:
                model_input_length = 1
            else:
                model_input_length = prompt_length + generated_length
            query_length = (
                prompt_length + generated_length
                if not has_static_cache
                else decoder_past_key_values.get_max_cache_shape()
            )

            expected_shape = (
                batch_size,
                config.num_attention_heads,
                model_input_length,
                query_length,
            )
            # check attn size
            self.assertListEqual(
                [layer_attention.shape for layer_attention in iter_attentions], [expected_shape] * len(iter_attentions)
            )

    def _check_encoder_attention_for_generate(self, attentions, batch_size, config, prompt_length):
        encoder_expected_shape = (batch_size, config.num_attention_heads, prompt_length, prompt_length)
        self.assertIsInstance(attentions, tuple)
        self.assertListEqual(
            [layer_attentions.shape for layer_attentions in attentions],
            [encoder_expected_shape] * len(attentions),
        )

    def _check_hidden_states_for_generate(
        self, batch_size, hidden_states, prompt_length, output_length, config, use_cache=False
    ):
        self.assertIsInstance(hidden_states, tuple)
        self.assertListEqual(
            [isinstance(iter_hidden_states, tuple) for iter_hidden_states in hidden_states],
            [True] * len(hidden_states),
        )
        self.assertEqual(len(hidden_states), (output_length - prompt_length))

        # When `output_hidden_states=True`, each iteration of generate appends the hidden states corresponding to the
        # new token(s)
        # NOTE: `StaticCache` may have different lengths on different layers, if this test starts failing add more
        # elaborate checks
        for generated_length, iter_hidden_states in enumerate(hidden_states):
            # regardless of using cache, the first forward pass will have the full prompt as input
            if use_cache and generated_length > 0:
                model_input_length = 1
            else:
                model_input_length = prompt_length + generated_length
            expected_shape = (batch_size, model_input_length, config.hidden_size)
            # check hidden size
            self.assertListEqual(
                [layer_hidden_states.shape for layer_hidden_states in iter_hidden_states],
                [expected_shape] * len(iter_hidden_states),
            )

    def _check_encoder_hidden_states_for_generate(self, hidden_states, batch_size, config, prompt_length):
        encoder_expected_shape = (batch_size, prompt_length, config.hidden_size)
        self.assertIsInstance(hidden_states, tuple)
        self.assertListEqual(
            [layer_hidden_states.shape for layer_hidden_states in hidden_states],
            [encoder_expected_shape] * len(hidden_states),
        )

    def _get_conv_state_shape(self, batch_size: int, config):
        # Default conv state shape, for linear attention models - can vary based on models so this function is convenient
        # to easily check caches
        # Note that non-mamba models will NOT have the config fields - it does not matter as they will only use attention
        # cache layers, so the None default values will not be used
        intermediate_size = getattr(config, "intermediate_size", None)
        conv_kernel = getattr(config, "conv_kernel", None)
        return (batch_size, intermediate_size, conv_kernel)

    def _get_recurrent_state_shape(self, batch_size: int, config):
        # Default recurrent state shape, for linear attention models - can vary based on models so this function is convenient
        # to easily check caches
        # Note that non-mamba models will NOT have the config fields - it does not matter as they will only use attention
        # cache layers, so the None default values will not be used
        intermediate_size = getattr(config, "intermediate_size", None)
        state_size = getattr(config, "state_size", None)
        return (batch_size, intermediate_size, state_size)

    def _check_past_key_values_for_generate(self, batch_size, past_key_values, seq_length, config):
        # Raise a useful error, asking to explicitly override the method
        if not isinstance(past_key_values, Cache):
            raise ValueError("The cache is not standard! Please overwrite `_check_past_key_values_for_generate`")

        # In this case, we simply call recursively the function on both internal caches
        if isinstance(past_key_values, EncoderDecoderCache):
            self._check_past_key_values_for_generate(
                batch_size, past_key_values.self_attention_cache, seq_length, config
            )
            # For cross attention cache, the seq_length depends on the model, so we remove that dim
            self._check_past_key_values_for_generate(batch_size, past_key_values.cross_attention_cache, None, config)
            return

        # Use the correct config
        config = config.get_text_config(decoder=True)

        # (batch, kv heads, seq_length, head_dim)
        # Only pure mamba models do not have num_attention_heads defined in config, so it can never be 1 in practice for attention models
        num_attention_heads = getattr(config, "num_attention_heads", 1)
        num_kv_heads = getattr(config, "num_key_value_heads", num_attention_heads)
        hidden_size = getattr(config, "d_model", config.hidden_size)
        head_dim = getattr(config, "head_dim", hidden_size // num_attention_heads)

        # For cross attention cache, the seq_length depends on the model, so we remove that dim
        attention_shape = (
            (batch_size, num_kv_heads, seq_length, head_dim)
            if seq_length is not None
            else (batch_size, num_kv_heads, head_dim)
        )

        # For mamba layers
        conv_shape = self._get_conv_state_shape(batch_size, config)
        recurrent_shape = self._get_recurrent_state_shape(batch_size, config)

        # Check the size is coherent
        num_hidden_layers = config.num_hidden_layers
        if getattr(config, "num_kv_shared_layers", None) is not None:
            num_hidden_layers -= config.num_kv_shared_layers
        self.assertEqual(num_hidden_layers, len(past_key_values))

        # Check each layer has the correct shape
        for layer in past_key_values.layers:
            # Mamba + Attention layer cache
            if type(layer) is LinearAttentionAndFullAttentionLayer:
                # Remove the seq_length dim for cross-attention cache (it changes based on the model)
                keys = layer.keys if seq_length is not None else layer.keys[:, :, 0, :]
                values = layer.values if seq_length is not None else layer.values[:, :, 0, :]
                self.assertEqual(keys.shape, attention_shape)
                self.assertEqual(values.shape, attention_shape)
                self.assertEqual(layer.conv_states.shape, conv_shape)
                # May not be used (e.g. lfm2)
                if layer.is_recurrent_states_initialized:
                    self.assertEqual(layer.recurrent_states.shape, recurrent_shape)
            # Mamba only layer cache
            elif type(layer) is LinearAttentionLayer:
                self.assertEqual(layer.conv_states.shape, conv_shape)
                # May not be used (e.g. lfm2)
                if layer.is_recurrent_states_initialized:
                    self.assertEqual(layer.recurrent_states.shape, recurrent_shape)
            # Attention only layer type
            else:
                # Remove the seq_length dim for cross-attention cache (it changes based on the model)
                keys = layer.keys if seq_length is not None else layer.keys[:, :, 0, :]
                values = layer.values if seq_length is not None else layer.values[:, :, 0, :]
                self.assertEqual(keys.shape, attention_shape)
                self.assertEqual(values.shape, attention_shape)

    def _check_sequence_inside_sequence(self, tensor_1, tensor_2):
        # check if tensor_1 inside tensor_2 or tensor_2 inside tensor_1.
        # set to same device. we don't care what device.

        if not isinstance(tensor_1, list):
            tensor_1 = tensor_1.tolist()
        if not isinstance(tensor_2, list):
            tensor_2 = tensor_2.tolist()

        in_order = len(tensor_1) <= len(tensor_2)
        longer = tensor_2 if in_order else tensor_1
        shorter = tensor_1 if in_order else tensor_2

        flag = False
        chunk_size = len(shorter)
        for chunk_idx in range(len(longer) - chunk_size + 1):
            subseq = longer[chunk_idx : chunk_idx + chunk_size]
            if subseq == shorter:
                flag = True
                break

        self.assertTrue(flag)

    def _check_caches_are_equal(self, cache1: Cache, cache2: Cache):
        if not isinstance(cache1, Cache) or not isinstance(cache2, Cache):
            raise ValueError("The cache is not standard! Please overwrite `_check_caches_are_equal`")

        # In this case, we simply call recursively the function on both internal caches
        if isinstance(cache1, EncoderDecoderCache):
            self._check_caches_are_equal(cache1.self_attention_cache, cache2.self_attention_cache)
            self._check_caches_are_equal(cache1.cross_attention_cache, cache2.cross_attention_cache)
            return

        if not len(cache1) == len(cache2):
            raise ValueError("Both caches do not have the same number of layers.")

        num_layers = len(cache1)
        for idx in range(num_layers):
            self.assertEqual(type(cache1.layers[idx]), type(cache2.layers[idx]))

            # Mamba + Attention layer
            if type(cache1.layers[idx]) is LinearAttentionAndFullAttentionLayer:
                torch.testing.assert_close(cache1.layers[idx].keys, cache2.layers[idx].keys)
                torch.testing.assert_close(cache1.layers[idx].values, cache2.layers[idx].values)
                torch.testing.assert_close(cache1.layers[idx].conv_states, cache2.layers[idx].conv_states)
                # May not be used (e.g. lfm2)
                if cache1.layers[idx].is_recurrent_states_initialized:
                    torch.testing.assert_close(
                        cache1.layers[idx].recurrent_states, cache2.layers[idx].recurrent_states
                    )
            # Mamba layer
            elif type(cache1.layers[idx]) is LinearAttentionLayer:
                torch.testing.assert_close(cache1.layers[idx].conv_states, cache2.layers[idx].conv_states)
                # May not be used (e.g. lfm2)
                if cache1.layers[idx].is_recurrent_states_initialized:
                    torch.testing.assert_close(
                        cache1.layers[idx].recurrent_states, cache2.layers[idx].recurrent_states
                    )
            # Attention layer
            else:
                torch.testing.assert_close(cache1.layers[idx].keys, cache2.layers[idx].keys)
                torch.testing.assert_close(cache1.layers[idx].values, cache2.layers[idx].values)


@require_torch
class UtilsFunctionsTest(unittest.TestCase):
    def test_speculative_sampling(self):
        # assume vocab size 10, input length 5 + 3 generated candidates
        candidate_input_ids = torch.tensor([[8, 0, 3, 9, 8, 1, 4, 5]])  # input tokens
        candidate_logits = torch.tensor(
            [
                [
                    [-10.0, 10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0],  # generated 1
                    [-10.0, -10.0, -10.0, -10.0, 10.0, -10.0, -10.0, -10.0, -10.0, -10.0],  # generated 4
                    [-10.0, -10.0, -10.0, -10.0, -10.0, 10.0, -10.0, -10.0, -10.0, -10.0],  # generated 5
                ]
            ]
        )
        candidate_length = 3
        inf = float("inf")
        new_logits = torch.tensor(
            [
                [
                    [-10.0, 10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0],  # accepts 1
                    [-10.0, -10.0, -10.0, -10.0, 10.0, -10.0, -10.0, -10.0, -10.0, -10.0],  # accepts 4
                    [-inf, -inf, -inf, -inf, -inf, -inf, -inf, -inf, 10.0, -inf],  # rejects 5, accepts 8
                    [-10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0],  # N/A
                ]
            ]
        )
        last_assistant_token_is_eos = False
        validated_tokens, n_matches = _speculative_sampling(
            candidate_input_ids,
            candidate_logits,
            candidate_length,
            new_logits,
            last_assistant_token_is_eos,
        )
        self.assertTrue(n_matches.item() == 2)
        self.assertTrue(validated_tokens.tolist()[0] == [1, 4, 8])

    def test_speculative_sampling_target_distribution(self):
        """
        Asserts that the target distribution is preserved.
        Should help with catching issues like #32867.
        """
        # assume vocab size 10, input length 5 + 3 generated candidates
        candidate_input_ids = torch.tensor([[8, 0, 3, 9, 8, 1, 4, 5]])  # input tokens
        candidate_logits = torch.tensor(
            [
                [
                    [-10.0, 10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0, -10.0],  # generated 1
                    [-10.0, -10.0, -10.0, -10.0, 10.0, -10.0, -10.0, -10.0, -10.0, -10.0],  # generated 4
                    [-10.0, -10.0, -10.0, -10.0, -10.0, 10.0, -10.0, -10.0, -10.0, -10.0],  # generated 5
                ]
            ]
        )
        candidate_length = 3
        inf = float("inf")
        new_logits = torch.tensor(
            [
                [
                    # accepts 1:
                    [-inf, 10.0, -inf, -inf, -inf, -inf, -inf, -inf, -inf, -inf],
                    # accepts 4:
                    [-inf, -inf, -inf, -inf, 10.0, -inf, -inf, -inf, -inf, -inf],
                    # most likely to be 1 or 8, less likely to be 3, then 7, and should never be any other value:
                    [-inf, 2.0, -inf, 1.0, -inf, -inf, -inf, -0.01, 2.0, -inf],
                    # N/A:
                    [-inf, -inf, -inf, -inf, -inf, -inf, -inf, -inf, -inf, -inf],
                ]
            ]
        )
        last_assistant_token_is_eos = False
        last_validated_token = []
        for _ in range(10_000):
            validated_tokens, n_matches = _speculative_sampling(
                candidate_input_ids,
                candidate_logits,
                candidate_length,
                new_logits,
                last_assistant_token_is_eos,
            )
            self.assertTrue(n_matches.item() == 2)
            self.assertTrue(validated_tokens.tolist()[0][0] == 1)
            self.assertTrue(validated_tokens.tolist()[0][1] == 4)
            self.assertTrue(validated_tokens.tolist()[0][2] in [1, 3, 7, 8])
            last_validated_token.append(validated_tokens.tolist()[0][2])
        # check that the most likely tokens are selected more often than the less likely ones
        last_token_counts = collections.Counter(last_validated_token)
        self.assertTrue(last_token_counts[1] > last_token_counts[3] > last_token_counts[7] > 0)
        self.assertTrue(last_token_counts[8] > last_token_counts[3])


global_rng = random.Random()


# Copied from tests.test_modeling_common.ids_tensor
def ids_tensor(shape, vocab_size, rng=None, name=None):
    #  Creates a random int32 tensor of the shape within the vocab size
    if rng is None:
        rng = global_rng

    total_dims = 1
    for dim in shape:
        total_dims *= dim

    values = []
    for _ in range(total_dims):
        values.append(rng.randint(0, vocab_size - 1))

    return torch.tensor(data=values, dtype=torch.long, device=torch_device).view(shape).contiguous()


# Copied from tests.test_modeling_common.floats_tensor
def floats_tensor(shape, scale=1.0, rng=None, name=None):
    """Creates a random float32 tensor"""
    if rng is None:
        rng = global_rng

    total_dims = 1
    for dim in shape:
        total_dims *= dim

    values = []
    for _ in range(total_dims):
        values.append(rng.random() * scale)

    return torch.tensor(data=values, dtype=torch.float, device=torch_device).view(shape).contiguous()


@pytest.mark.generate
@require_torch
class GenerationIntegrationTests(unittest.TestCase):
    def test_generation_config_defaults(self):
        "Tests that we can set config value to a global default. See https://github.com/huggingface/transformers/issues/42762"
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        input_ids = tokenizer("Hello", return_tensors="pt").input_ids.to(torch_device)

        # Set the min/max_length to non-default value
        model.generation_config.min_length = 50
        model.generation_config.max_length = 50

        # Explicit generate with min/max_length set to global default values
        generation_config = GenerationConfig(
            temperature=1.0,
            max_length=20,
            min_length=0,
            do_sample=False,
            eos_token_id=-1,  # don't stop before max length reached
        )

        runtime_generation_config, _ = model._prepare_generation_config(generation_config=generation_config)
        self.assertEqual(runtime_generation_config.max_length, 20)
        self.assertEqual(runtime_generation_config.min_length, 0)

        out = model.generate(input_ids, generation_config=generation_config)
        self.assertTrue(len(out[0]) == 20)  # generated max_length=20 tokens, not 50!

        # Lastly try saving to make sure no errors are raised about
        # "generation params in config" or during config validation (#43175)
        with tempfile.TemporaryDirectory() as tmpdirname:
            model.generation_config.cache_implementation = "dynamic"
            model.generation_config.use_cache = None
            model.save_pretrained(tmpdirname)

    def test_generation_config_deprecation(self):
        import logging as pylogging

        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        input_ids = tokenizer("Hello", return_tensors="pt").input_ids.to(torch_device)

        logger = pylogging.getLogger("transformers")

        class OnWarningHandler(pylogging.Handler):
            def __init__(self):
                super().__init__()
                self.warnings = []

            def emit(self, record):
                msg = record.getMessage()
                if "Passing `generation_config` together with" in msg:
                    self.warnings.append(msg)

        warningHandler = OnWarningHandler()
        logger.addHandler(warningHandler)

        try:
            # Providing generation_config and kwargs is deprecated, so we expect a warning here.
            #
            # We're using logging_once, make sure that we emit this warning in any case by clearing the
            # cache on warning_once
            logging.warning_once.cache_clear()
            generation_config = GenerationConfig(temperature=1.0)
            _ = model.generate(input_ids, generation_config=generation_config, do_sample=False)
            self.assertTrue(len(warningHandler.warnings) == 1)

            # Providing no generation config, only kwargs is not deprecated. No further deprecation warnings
            # should have been sent.
            logging.warning_once.cache_clear()
            _ = model.generate(input_ids, do_sample=False)
            self.assertTrue(len(warningHandler.warnings) == 1)
        finally:
            logger.removeHandler(warningHandler)

    def test_inputs_embeds_warn_without_ids_for_token_based_logit_processors(self):
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2", device_map=torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        inputs = tokenizer("Hello world", return_tensors="pt").to(torch_device)
        ids = inputs["input_ids"]
        embeds = model.get_input_embeddings()(ids)

        # Check that it raises with only embeds
        with self.assertWarnsRegex(UserWarning, "apply the penalty only to newly generated tokens, not to the prompt"):
            _ = model.generate(inputs_embeds=embeds, max_new_tokens=5, repetition_penalty=1.1)

        # Check that it does NOT raise with both ids and embeds
        with warnings.catch_warnings(record=True) as w:
            warnings.simplefilter("always")
            _ = model.generate(input_ids=ids, inputs_embeds=embeds, max_new_tokens=5, repetition_penalty=1.1)
            self.assertFalse(
                any(
                    "apply the penalty only to newly generated tokens, not to the prompt" in str(warn.message)
                    for warn in w
                )
            )

        # Check that it raises with only embeds
        with self.assertWarnsRegex(
            UserWarning, "n-gram constraints only to newly generated tokens, not to the prompt"
        ):
            _ = model.generate(inputs_embeds=embeds, max_new_tokens=5, no_repeat_ngram_size=2)

        # Check that it does NOT raise with both ids and embeds
        with warnings.catch_warnings(record=True) as w:
            warnings.simplefilter("always")
            _ = model.generate(input_ids=ids, inputs_embeds=embeds, max_new_tokens=5, no_repeat_ngram_size=2)
            self.assertFalse(
                any(
                    "n-gram constraints only to newly generated tokens, not to the prompt" in str(warn.message)
                    for warn in w
                )
            )

    @slow
    def test_beam_search_early_stop_heuristic(self):
        """Regression test for #38778 (early stopping needs to be tracked at a batch level)"""
        EXPECTED_OUTPUT = (
            "<|user|>\nWhat is 3+5?\n<|assistant|>\nThe sum of 3 and 5 is 8. \n\nSo, 3 + 5 = 8. \n\n"
            "Let's confirm this using Python code:\n\n```python\n# Define the numbers\nnum1 = 3\nnum2 = 5\n\n"
            "# Calculate the sum\nresult = num1 + num2\n\n# Print the result\nprint(result)\n```\n"
            "```output\n8\n```\nThe sum of 3 and 5 is \\(\\boxed{8}\\)."
        )

        model = AutoModelForCausalLM.from_pretrained("allenai/OLMo-2-0425-1B-Instruct").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("allenai/OLMo-2-0425-1B-Instruct", padding_side="left")
        generation_config = GenerationConfig(
            num_beams=10,
            max_new_tokens=256,
            length_penalty=2,
        )
        # batch of 1
        question = [{"role": "user", "content": "What is 3+5?"}]
        question = tokenizer.apply_chat_template(
            question, tokenize=False, add_generation_prompt=True, return_tensors="pt"
        )
        inputs = tokenizer(question, return_tensors="pt", padding=True).to(torch_device)
        outputs = model.generate(**inputs, generation_config=generation_config)
        responses = tokenizer.batch_decode(outputs, skip_special_tokens=True)
        self.assertEqual(responses[0], EXPECTED_OUTPUT)

        # batch of 2
        question = [{"role": "user", "content": "What is 3+5?"}]
        cot_question = [
            {
                "role": "user",
                "content": "What is 3+5? Explain your reasoning step by step, and provide the final answer at the end.",
            }
        ]
        question = tokenizer.apply_chat_template(
            question, tokenize=False, add_generation_prompt=True, return_tensors="pt"
        )
        cot_question = tokenizer.apply_chat_template(
            cot_question, tokenize=False, add_generation_prompt=True, return_tensors="pt"
        )
        inputs = tokenizer([question, cot_question], return_tensors="pt", padding=True).to(torch_device)

        outputs = model.generate(**inputs, generation_config=generation_config)
        responses = tokenizer.batch_decode(outputs, skip_special_tokens=True)
        self.assertEqual(responses[0], EXPECTED_OUTPUT)

    def test_max_length_if_input_embeds(self):
        article = "Today a dragon flew over Paris."
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        input_ids = tokenizer(article, return_tensors="pt").input_ids.to(torch_device)
        inputs_embeds = model.get_input_embeddings()(input_ids)

        max_length = 20
        input_len = input_ids.shape[-1]
        out_gen = model.generate(input_ids=input_ids, max_length=max_length)
        out_gen_embeds = model.generate(inputs_embeds=inputs_embeds, max_length=max_length)
        self.assertEqual(out_gen.shape[-1], input_len + out_gen_embeds.shape[-1])

    def test_min_length_if_input_embeds(self):
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        input_ids = tokenizer("Today a dragon flew over Paris.", return_tensors="pt").input_ids.to(torch_device)
        inputs_embeds = model.get_input_embeddings()(input_ids)

        min_length = 10
        input_len = input_ids.shape[-1]
        out_gen = model.generate(input_ids=input_ids, min_length=min_length)
        out_gen_embeds = model.generate(inputs_embeds=inputs_embeds, min_length=min_length)
        self.assertEqual(out_gen.shape[-1], input_len + out_gen_embeds.shape[-1])

    def test_custom_stopping_criteria_overload_error(self):
        article = """Justin Timberlake and Jessica Biel, welcome to parenthood."""
        bart_tokenizer = BartTokenizer.from_pretrained("sshleifer/bart-tiny-random")
        bart_model = BartForConditionalGeneration.from_pretrained("sshleifer/bart-tiny-random").to(torch_device)

        input_ids = bart_tokenizer(article, return_tensors="pt").input_ids.to(torch_device)
        stopping_criteria = StoppingCriteriaList()
        stopping_criteria.append(MaxLengthCriteria(max_length=42))
        logger = logging.get_logger("transformers.generation.utils")

        logger.warning_once.cache_clear()
        with CaptureLogger(logger) as cl:
            bart_model.generate(input_ids, stopping_criteria=stopping_criteria)
        self.assertTrue(
            "custom stopping criteria of type <class 'transformers.generation.stopping_criteria.MaxLengthCriteria'> has been passed to `.generate()`, but it was also created in `.generate()`, given its parameterization"
            in cl.out
        )

        logger.warning_once.cache_clear()
        with CaptureLogger(logger) as cl:
            bart_model.generate(input_ids, stopping_criteria=stopping_criteria, max_length=32)
        self.assertTrue(
            "custom stopping criteria of type <class 'transformers.generation.stopping_criteria.MaxLengthCriteria'> has been passed to `.generate()`, but it was also created in `.generate()`, given its parameterization"
            in cl.out
        )

    def test_custom_stopping_criteria(self):
        article = """Justin Timberlake and Jessica Biel, welcome to parenthood."""
        bart_tokenizer = BartTokenizer.from_pretrained("sshleifer/bart-tiny-random")
        bart_model = BartForConditionalGeneration.from_pretrained("sshleifer/bart-tiny-random").to(torch_device)
        input_ids = bart_tokenizer(article, return_tensors="pt").input_ids.to(torch_device)

        class DummyCriteria(StoppingCriteria):
            def __call__(self, input_ids: torch.LongTensor, scores: torch.FloatTensor, **kwargs) -> bool:
                return input_ids.shape[-1] >= 20

        stopping_criteria = StoppingCriteriaList()
        stopping_criteria.append(DummyCriteria())

        self.assertEqual(
            list(bart_model.generate(input_ids, stopping_criteria=stopping_criteria, max_length=22).shape),
            [1, 20],
        )
        self.assertEqual(
            list(bart_model.generate(input_ids, stopping_criteria=stopping_criteria, max_length=18).shape),
            [1, 18],
        )

    # TODO (joao): replace `stop_sequence` in the pipeline by the more recent `generate` functionality
    def test_stop_sequence_stopping_criteria(self):
        prompt = """Hello I believe in"""
        generator = pipeline("text-generation", model="hf-internal-testing/tiny-random-bart")
        output = generator(prompt, max_new_tokens=10, do_sample=False)
        self.assertEqual(
            output,
            [{"generated_text": ("Hello I believe in we we we we we we we we we")}],
        )

        output = generator(prompt, stop_sequence=" we", do_sample=False)
        self.assertEqual(output, [{"generated_text": "Hello I believe in we"}])

    def test_generate_non_nlp_input_ids_as_kwarg(self):
        model = ImageGPTForCausalImageModeling.from_pretrained("hf-internal-testing/tiny-random-imagegpt")
        model = model.to(torch_device)
        input_ids = ids_tensor((3, 5), vocab_size=10)

        output_sequences_kwargs = model.generate(input_ids=input_ids, max_length=10).cpu()
        output_sequences = model.generate(input_ids, max_length=10).cpu()

        self.assertListEqual(output_sequences.tolist(), output_sequences_kwargs.tolist())
        self.assertEqual(output_sequences.shape, (3, 10))

    def test_generate_input_values_as_encoder_kwarg(self):
        input_values = floats_tensor((2, 250))
        model = SpeechEncoderDecoderModel.from_pretrained("hf-internal-testing/tiny-random-speech-encoder-decoder")
        model = model.to(torch_device)
        output_sequences_kwargs = model.generate(input_values=input_values, max_length=5).cpu()
        output_sequences = model.generate(input_values, max_length=5).cpu()

        self.assertListEqual(output_sequences.tolist(), output_sequences_kwargs.tolist())
        self.assertEqual(output_sequences.shape, (2, 5))

    @slow
    def test_generate_inputs_embeds_one_token(self):
        "Tests that we can generate legible text from a single token input embedding. See #41863 for details"
        model = AutoModelForCausalLM.from_pretrained("gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("gpt2")
        inputs_embeds = model.get_input_embeddings()(torch.tensor([[tokenizer.bos_token_id]], device=torch_device))

        output = model.generate(
            inputs_embeds=inputs_embeds, do_sample=False, max_length=15, pad_token_id=tokenizer.eos_token_id
        )
        text = tokenizer.batch_decode(output, skip_special_tokens=True)[0]
        self.assertEqual(text, "\nThe first time I saw the new version of the game, I")

    @slow
    def test_green_red_watermark_generation(self):
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        tokenizer.pad_token_id = tokenizer.eos_token_id
        model_inputs = tokenizer("I will be", return_tensors="pt").to(torch_device)
        input_len = model_inputs["input_ids"].shape[-1]

        # generation should work with both input types: WatermarkingConfig or Dict, so let's check it here :)
        watermark_config = WatermarkingConfig(bias=2.5, seeding_scheme="selfhash")
        _ = model.generate(**model_inputs, watermarking_config=watermark_config, do_sample=False, max_length=15)

        # We will not check watermarked text, since we check it in `logits_processors` tests
        # Checking if generated ids are as expected fails on different hardware
        args = {
            "bias": 2.0,
            "context_width": 1,
            "seeding_scheme": "selfhash",
            "greenlist_ratio": 0.25,
            "hashing_key": 15485863,
        }
        output = model.generate(**model_inputs, do_sample=False, max_length=15)
        output_selfhash = model.generate(**model_inputs, watermarking_config=args, do_sample=False, max_length=15)

        # Check that the detector is detecting watermarked text
        detector = WatermarkDetector(model_config=model.config, device=torch_device, watermarking_config=args)
        detection_out_watermarked = detector(output_selfhash[:, input_len:], return_dict=True)
        detection_out = detector(output[:, input_len:], return_dict=True)

        self.assertListEqual(detection_out_watermarked.prediction.tolist(), [True])
        self.assertListEqual(detection_out.prediction.tolist(), [False])

    """Check the mean bias inserted by the watermarking algorithm."""

    @slow
    def test_synthid_text_watermark_generation_mean_expected_bias(self):
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        tokenizer.pad_token_id = tokenizer.eos_token_id
        model_inputs = tokenizer("I will be", return_tensors="pt").to(torch_device)
        input_len = 5
        batch_size = 200

        # generation should work with both input types: WatermarkingConfig or Dict, so let's check it here :)
        watermark_config = SynthIDTextWatermarkingConfig(keys=[10, 20], ngram_len=5, debug_mode=True)
        logits_processor = watermark_config.construct_processor(model.config.vocab_size, torch_device)
        mean_g_values_repeats = []
        for _ in range(40):
            input_ids = torch.zeros(
                (batch_size, input_len),
                dtype=torch.int64,
                device=torch_device,
            )
            model_inputs = {
                "input_ids": input_ids,
                "attention_mask": torch.ones_like(input_ids, device=torch_device),
            }
            output = model.generate(
                **model_inputs, watermarking_config=watermark_config, do_sample=True, max_length=500, top_k=1000
            )
            g_values = logits_processor.compute_g_values(input_ids=output[:, input_len:])
            context_repetition_mask = logits_processor.compute_context_repetition_mask(
                input_ids=output[:, input_len:],
            ).unsqueeze(dim=2)

            mean_g_values = torch.masked.mean(
                g_values,
                mask=context_repetition_mask,
                dim=0,
                keepdim=True,
                dtype=torch.float64,
            )
            mean_g_values_repeats.append(mean_g_values)

        mean_g_values = torch.concat(mean_g_values_repeats, dim=0).mean(dim=0)
        expected_mean_g_value = logits_processor.expected_mean_g_value(
            vocab_size=model.config.vocab_size,
        )
        atol = 0.03
        is_close = torch.isclose(
            mean_g_values,
            torch.tensor(expected_mean_g_value, dtype=torch.float64),
            atol=atol,
            rtol=0,
        )
        self.assertTrue(torch.all(is_close))

    @slow
    def test_TopH_example_integration(self):
        tokenizer = AutoTokenizer.from_pretrained("Qwen/Qwen2.5-3B")
        model = AutoModelForCausalLM.from_pretrained("Qwen/Qwen2.5-3B")
        tokenizer.pad_token = tokenizer.eos_token
        model.config.pad_token_id = tokenizer.pad_token_id
        encoder_input_str = "Tell me a joke about a monkey."
        input_ids = tokenizer(encoder_input_str, return_tensors="pt")

        set_seed(42)

        outputs = model.generate(
            **input_ids,
            eos_token_id=model.config.eos_token_id,
            do_sample=True,
            temperature=1.0,
            top_h=0.4,
            max_new_tokens=32,
            pad_token_id=tokenizer.pad_token_id,
        )
        outputs = tokenizer.batch_decode(outputs, skip_special_tokens=True)
        self.assertListEqual(
            outputs,
            [
                'Tell me a joke about a monkey. Why did the monkey go to the doctor? Because he was feeling a little "tropic"!'
            ],
        )

    @slow
    def test_beam_search_example_integration(self):
        # exactly the example provided in the docstrings of beam search, which previously
        # failed after directly copying from it. Refer to PR #15555
        tokenizer = AutoTokenizer.from_pretrained("google-t5/t5-base")
        model = AutoModelForSeq2SeqLM.from_pretrained("google-t5/t5-base")

        encoder_input_str = "translate English to German: How old are you?"
        encoder_input_ids = tokenizer(encoder_input_str, return_tensors="pt").input_ids

        # lets run beam search using 3 beams
        num_beams = 3
        # define decoder start token ids
        input_ids = torch.ones((1, 1), device=model.device, dtype=torch.long)
        input_ids = input_ids * model.config.decoder_start_token_id

        # add encoder_outputs to model keyword arguments
        model_kwargs = {"encoder_outputs": model.get_encoder()(encoder_input_ids, return_dict=True)}

        outputs = model.generate(
            input_ids, num_beams=num_beams, min_length=5, eos_token_id=model.config.eos_token_id, **model_kwargs
        )
        outputs = tokenizer.batch_decode(outputs, skip_special_tokens=True)

        self.assertListEqual(outputs, ["Wie alt bist du?"])

    @slow
    def test_cfg_mixin(self):
        model = GPT2LMHeadModel.from_pretrained("openai-community/gpt2").to(torch_device)
        tokenizer = GPT2Tokenizer.from_pretrained("openai-community/gpt2")

        input = tokenizer(["The dragon flew over Paris,"], return_tensors="pt", return_attention_mask=True)
        input["input_ids"] = input["input_ids"].to(torch_device)
        input["attention_mask"] = input["attention_mask"].to(torch_device)

        outputs = model.generate(**input, max_new_tokens=32, guidance_scale=1.5)
        generated_text = tokenizer.batch_decode(outputs, skip_special_tokens=True)

        self.assertListEqual(
            generated_text,
            [
                "The dragon flew over Paris, landing in the Rue de la Bastille. The crowd was so excited "
                'that they had to leave the city.\n\n"We\'re going to Paris!"\n'
            ],
        )

        neg = tokenizer(["France,"], return_tensors="pt", return_attention_mask=True)
        neg["input_ids"] = neg["input_ids"].to(torch_device)
        neg["attention_mask"] = neg["attention_mask"].to(torch_device)
        outputs = model.generate(
            **input,
            max_new_tokens=32,
            guidance_scale=1.5,
            negative_prompt_ids=neg["input_ids"],
            negative_prompt_attention_mask=neg["attention_mask"],
        )
        generated_text = tokenizer.batch_decode(outputs, skip_special_tokens=True)

        self.assertListEqual(
            generated_text,
            [
                'The dragon flew over Paris, landing on the pavement.\n\n"Paris!"\n\n"Paris!"\n\n"'
                'Paris!"\n\n"Paris!"\n\n"Paris!"\n\n'
            ],
        )

    @slow
    def test_per_row_stopping_criteria(self):
        text = [
            "They completed the challenging puzzle, revealing the hidden",
            "Today a dragon flew over France",
            "The aroma of freshly baked pizza filled the kitchen",
        ]
        stop_strings = ["secrets"]

        model = AutoModelForCausalLM.from_pretrained("openai-community/gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("openai-community/gpt2")
        tokenizer.padding_side = "left"
        tokenizer.pad_token_id = tokenizer.eos_token_id
        input_ids = tokenizer(text, return_tensors="pt", padding="longest", add_special_tokens=False).input_ids.to(
            torch_device
        )

        # normal generation with one stopping criteria
        out = model.generate(input_ids, max_length=15)
        out_text = tokenizer.batch_decode(out)
        expected_out = [
            "They completed the challenging puzzle, revealing the hidden secrets of the world.\n",
            "<|endoftext|><|endoftext|><|endoftext|>Today a dragon flew over France and the French government was forced",
            "The aroma of freshly baked pizza filled the kitchen with a sense of freshness",
        ]
        self.assertListEqual(out_text, expected_out)

        # generation should stop at "secrets" for first batch only, filling the rest with eos tokens
        out = model.generate(input_ids, max_length=15, stop_strings=stop_strings, tokenizer=tokenizer)
        out_text = tokenizer.batch_decode(out)
        expected_out = [
            "They completed the challenging puzzle, revealing the hidden secrets<|endoftext|><|endoftext|><|endoftext|><|endoftext|><|endoftext|>",
            "<|endoftext|><|endoftext|><|endoftext|>Today a dragon flew over France and the French government was forced",
            "The aroma of freshly baked pizza filled the kitchen with a sense of freshness",
        ]
        self.assertListEqual(out_text, expected_out)

    def test_batched_decoder_start_id(self):
        articles = [
            "Justin Timberlake and Jessica Biel, welcome to parenthood.",
            "Michael Phelps is arguably the most decorated Olympian of all time.",
        ]
        bart_tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-bart")
        bart_model = BartForConditionalGeneration.from_pretrained("hf-internal-testing/tiny-random-bart").to(
            torch_device
        )
        input_ids = bart_tokenizer(articles, return_tensors="pt", padding=True).input_ids.to(torch_device)
        decoder_start_token_id = bart_model.generation_config.decoder_start_token_id
        decoder_start_token_id_batch = [decoder_start_token_id] * input_ids.shape[0]

        outputs = bart_model.generate(input_ids, decoder_start_token_id=decoder_start_token_id)

        outputs_batched_ids = bart_model.generate(input_ids, decoder_start_token_id=decoder_start_token_id_batch)

        self.assertListEqual(outputs.tolist(), outputs_batched_ids.tolist())

    def test_decoder_start_id_from_config(self):
        # Refer to: (#30899)
        articles = [
            "Justin Timberlake and Jessica Biel, welcome to parenthood.",
            "Michael Phelps is arguably the most decorated Olympian of all time.",
        ]
        bart_tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-bart")
        bart_model = BartForConditionalGeneration.from_pretrained("hf-internal-testing/tiny-random-bart").to(
            torch_device
        )
        input_ids = bart_tokenizer(articles, return_tensors="pt", padding=True).input_ids.to(torch_device)
        decoder_start_token_id = bart_model.generation_config.decoder_start_token_id

        # we should be able to take `decoder_start_token_id` from model's generation config if user passes a `GenerationConfig` type
        outputs = bart_model.generate(input_ids, generation_config=GenerationConfig(do_sample=False))

        # If the generatoin config has no `decoder_start_token_id` or `bos_token_id`, we will raise an error unless user passes it in config
        bart_model.generation_config.decoder_start_token_id = None
        bart_model.generation_config.bos_token_id = None
        outputs_with_user_id = bart_model.generate(
            input_ids,
            generation_config=GenerationConfig(do_sample=False, decoder_start_token_id=decoder_start_token_id),
        )

        self.assertListEqual(outputs.tolist(), outputs_with_user_id.tolist())

        with self.assertRaises(ValueError):
            outputs = bart_model.generate(input_ids, generation_config=GenerationConfig(do_sample=False))

    def test_logits_processor_not_inplace(self):
        article = "Today a dragon flew over Paris."
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        input_ids = tokenizer(article, return_tensors="pt").input_ids.to(torch_device)

        out = model.generate(input_ids, output_logits=True, output_scores=True, return_dict_in_generate=True)
        out_with_temp = model.generate(
            input_ids,
            temperature=0.5,
            do_sample=True,
            output_logits=True,
            output_scores=True,
            return_dict_in_generate=True,
        )

        # if no logits processor is used, scores == logits. Otherwise, the processor has to modify the scores
        self.assertListEqual(out.logits[-1].tolist(), out.scores[-1].tolist())
        self.assertNotEqual(out_with_temp.logits[-1].tolist(), out_with_temp.scores[-1].tolist())

    def test_eos_token_id_int_and_list_top_k_top_sampling(self):
        "Tests that `generate` can run with a list of EOS token ids."
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokens = tokenizer("Hello, my dog is cute and", return_tensors="pt").to(torch_device)

        eos_token_id = 846
        model.generate(**tokens, eos_token_id=eos_token_id)

        eos_token_id = [846, 198]
        model.generate(**tokens, eos_token_id=eos_token_id)

    def test_model_kwarg_encoder_signature_filtering(self):
        bart_tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-bart")
        article = """Hugging Face is a technology company based in New York and Paris."""
        input_ids = bart_tokenizer(article, return_tensors="pt").input_ids.to(torch_device)
        bart_model = BartForConditionalGeneration.from_pretrained("hf-internal-testing/tiny-random-bart").to(
            torch_device
        )
        output = bart_model.generate(input_ids).cpu().numpy()

        # Let's create a fake model that has a different signature. In particular, this fake model accepts "foo" as an
        # argument. Because "foo" is not in the encoder signature and doesn't start with "decoder_", it will be part of
        # the encoder kwargs prior to signature filtering, which would lead to an exception. But filtering kicks in and
        # saves the day.
        class FakeBart(BartForConditionalGeneration):
            def forward(self, decoder_input_ids, foo=None, **kwargs):
                return super().forward(decoder_input_ids=decoder_input_ids, **kwargs)

        bart_model = FakeBart.from_pretrained("hf-internal-testing/tiny-random-bart").to(torch_device)
        fake_output = bart_model.generate(input_ids, foo="bar").cpu().numpy()
        self.assertTrue(np.array_equal(output, fake_output))

        # Encoder signature filtering only kicks in if it doesn't accept wildcard kwargs. The following test will fail
        # because it doesn't do signature filtering.
        class FakeEncoder(bart_model.model.encoder.__class__):
            def forward(self, input_ids, **kwargs):
                # BartEncoder has wildcard kwargs in its signature, so let's raise `TypeError` here
                if "foo" in kwargs:
                    raise TypeError("Foo is not a valid `kwarg`")
                return super().forward(input_ids, **kwargs)

        fake_encoder = FakeEncoder(bart_model.config).to(torch_device)
        bart_model.model.encoder = fake_encoder

        # Normal generation still works (the output will be different because the encoder weights are different)
        fake_output = bart_model.generate(input_ids).cpu().numpy()
        with self.assertRaises(TypeError):
            # FakeEncoder.forward() accepts **kwargs -> no filtering -> type error due to unexpected input "foo"
            bart_model.generate(input_ids, foo="bar")

    def test_default_max_length_warning(self):
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        model.generation_config.pad_token_id = tokenizer.eos_token_id

        text = "Hello world"
        tokenized_inputs = tokenizer([text], return_tensors="pt")
        input_ids = tokenized_inputs.input_ids.to(torch_device)

        # Default generation config value of 20 -> emits warning
        with self.assertWarns(UserWarning):
            model.generate(input_ids)

        # Explicitly setting max_length to 20 -> no warning
        with warnings.catch_warnings(record=True) as warning_list:
            model.generate(input_ids, max_length=20)
            self.assertEqual(len(warning_list), 0)

        # Generation config max_length != 20 -> no warning
        with warnings.catch_warnings(record=True) as warning_list:
            # generation_config is modified -> legacy mode is disabled = generation_config takes precedence
            model.generation_config.max_length = 10
            model.generate(input_ids)
            self.assertEqual(len(warning_list), 0)

    def test_length_warning_assisted_generation(self):
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        assistant = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        model.generation_config.pad_token_id = tokenizer.eos_token_id
        assistant.generation_config.pad_token_id = tokenizer.eos_token_id

        text = "Hello world"
        tokenized_inputs = tokenizer([text], return_tensors="pt")
        input_ids = tokenized_inputs.input_ids.to(torch_device)

        # This should not raise any warning that min length is not feasible in candidate generation
        with warnings.catch_warnings(record=True) as warning_list:
            model.generate(
                input_ids,
                assistant_model=assistant,
                min_new_tokens=10,
                max_length=20,
            )
            self.assertEqual(len(warning_list), 0)

    def test_generated_length_assisted_generation(self):
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        assistant = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        model.generation_config.pad_token_id = tokenizer.eos_token_id
        assistant.generation_config.pad_token_id = tokenizer.eos_token_id

        text = "Hello world"
        tokenized_inputs = tokenizer([text], return_tensors="pt")
        input_ids = tokenized_inputs.input_ids.to(torch_device)
        input_length = input_ids.shape[-1]

        out = model.generate(
            input_ids,
            assistant_model=assistant,
            min_new_tokens=10,
            max_new_tokens=20,
        )
        self.assertTrue((10 + input_length) <= out.shape[-1] <= (20 + input_length))

        out = model.generate(
            input_ids,
            assistant_model=assistant,
            min_new_tokens=10,
        )
        self.assertTrue((input_length + 10) <= out.shape[-1])

        out = model.generate(
            input_ids,
            assistant_model=assistant,
            max_new_tokens=7,
        )
        self.assertTrue(out.shape[-1] <= (input_length + 7))

    def test_model_kwarg_assisted_decoding_decoder_only(self):
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        model.generation_config.pad_token_id = tokenizer.eos_token_id

        text = "Hello world"
        tokenized_inputs = tokenizer([text], return_tensors="pt")
        input_ids = tokenized_inputs.input_ids.to(torch_device)

        with sdpa_kernel([SDPBackend.EFFICIENT_ATTENTION, SDPBackend.MATH]):
            # Traditional way of generating text
            outputs_normal = model.generate(input_ids)
            self.assertEqual(outputs_normal.shape, (1, 20 + input_ids.shape[1]))

            # Should be different with token_type_ids
            outputs_tti = model.generate(
                input_ids,
                token_type_ids=torch.zeros(input_ids.shape, dtype=torch.long).to(torch_device),
            )
            with self.assertRaises(AssertionError):
                self.assertListEqual(outputs_tti.tolist(), outputs_normal.tolist())

            # Assistant model
            assistant = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
            assistant.config.pad_token_id = tokenizer.eos_token_id

            # If assisted generation passes model_kwargs correctly, should be same as previous
            outputs_assisted = model.generate(
                input_ids,
                token_type_ids=torch.zeros(input_ids.shape, dtype=torch.long).to(torch_device),
                assistant_model=assistant,
            )
            self.assertListEqual(outputs_assisted.tolist(), outputs_tti.tolist())

    def test_assisted_decoding_num_assistant_tokens_heuristic_schedule(self):
        # This test ensures that the assisted generation num_assistant_tokens 'heuristic' schedule works properly.

        prompt = "Alice and Bob"
        checkpoint = "EleutherAI/pythia-160m-deduped"
        tokenizer = AutoTokenizer.from_pretrained(checkpoint)
        inputs = tokenizer(prompt, return_tensors="pt")

        model = AutoModelForCausalLM.from_pretrained(checkpoint)

        assistant_model = model
        assistant_model.generation_config.num_assistant_tokens = 5
        assistant_model.generation_config.num_assistant_tokens_schedule = "heuristic"
        generation_kwargs = {
            "eos_token_id": -1,
            "max_new_tokens": 5,
            "do_sample": False,
            "assistant_model": assistant_model,
        }
        model.generate(**inputs, **generation_kwargs)
        self.assertEqual(assistant_model.generation_config.num_assistant_tokens, 11)

    def test_assisted_decoding_num_assistant_tokens_heuristic_transient_schedule(self):
        # This test ensures that the assisted generation num_assistant_tokens 'heuristic' schedule works properly.

        prompt = "Alice and Bob"
        checkpoint = "EleutherAI/pythia-160m-deduped"
        tokenizer = AutoTokenizer.from_pretrained(checkpoint)
        inputs = tokenizer(prompt, return_tensors="pt")

        model = AutoModelForCausalLM.from_pretrained(checkpoint)

        assistant_model = model
        assistant_model.generation_config.num_assistant_tokens = 5
        assistant_model.generation_config.num_assistant_tokens_schedule = "heuristic_transient"
        generation_kwargs = {
            "eos_token_id": -1,
            "max_new_tokens": 5,
            "do_sample": False,
            "assistant_model": assistant_model,
        }
        model.generate(**inputs, **generation_kwargs)
        # update_candidate_strategy is called once but assistant_model.generation_config.num_assistant_tokens should stay 5
        self.assertEqual(assistant_model.generation_config.num_assistant_tokens, 5)

    @slow
    def test_validate_assistant(self):
        # Generate a random sample:
        inputs = np.random.rand(160000)

        # Load a main encoder-decoder model:
        model_id = "openai/whisper-large-v2"
        processor = AutoProcessor.from_pretrained(model_id)
        model = AutoModelForSpeechSeq2Seq.from_pretrained(
            model_id,
            use_safetensors=True,
        )
        model.to(torch_device)

        # process the input:
        features = processor(inputs, return_tensors="pt").to(torch_device)

        # Load an encoder-decoder assistant with same encoder as the main model:
        assistant_distil_model_id = "distil-whisper/distil-large-v2"
        assistant_seq_to_seq = AutoModelForSpeechSeq2Seq.from_pretrained(
            assistant_distil_model_id,
            use_safetensors=True,
        ).to(torch_device)
        self.assertTrue(model.generate(**features, assistant_model=assistant_seq_to_seq).sum())

        # Load its decoder only version:
        assistant_causal_lm = AutoModelForCausalLM.from_pretrained(
            assistant_distil_model_id,
            use_safetensors=True,
        ).to(torch_device)
        self.assertTrue(model.generate(**features, assistant_model=assistant_causal_lm).sum())

        # Load an encoder-decoder assistant with a different encoder than the main model:
        assistant_distil_model_id = "openai/whisper-tiny"
        assistant_seq_to_seq = AutoModelForSpeechSeq2Seq.from_pretrained(
            assistant_distil_model_id,
            use_safetensors=True,
        ).to(torch_device)
        self.assertTrue(model.generate(**features, assistant_model=assistant_seq_to_seq).sum())

        # Load its decoder only version:
        assistant_causal_lm = AutoModelForCausalLM.from_pretrained(
            assistant_distil_model_id,
            use_safetensors=True,
        ).to(torch_device)
        # It will raise an error as the encoder of the main and assistant model are not compatible:
        with self.assertRaises(ValueError):
            model.generate(**features, assistant_model=assistant_causal_lm)

        # Load an encoder-decoder model with a different tokenizer than the main model:
        assistant_distil_model_id = "hf-internal-testing/tiny-random-SeamlessM4Tv2ForSpeechToText"
        assistant_seq_to_seq = AutoModelForSpeechSeq2Seq.from_pretrained(
            assistant_distil_model_id,
        ).to(torch_device)
        # This should raise an error as the main and assistant model don't use the same tokenizer:
        with self.assertRaises(ValueError):
            model.generate(**features, assistant_model=assistant_seq_to_seq)

    def test_compare_unprocessed_logit_scores(self):
        # Get unprocessed logit scores back from model generate function.
        # Assert that unprocessed logits from generate() are same as those from modal eval()

        # tell model to generate text and return unprocessed/unwarped logit scores
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        text = "generate yes or no: "
        input_ids = tokenizer([text], return_tensors="pt").input_ids.to(torch_device)

        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)

        with torch.no_grad():
            # Get logits for the next token from fwd pass
            logits_fwd = model(input_ids).logits[:, -1, :][0]

        # Get logits for the next token from generate function
        outputs = model.generate(
            input_ids=input_ids,
            return_dict_in_generate=True,
            output_logits=True,
            max_new_tokens=1,
            do_sample=True,
        )
        logits_gen = outputs.logits[0][0]

        # assert that unprocessed logits from generate() are same as those from modal eval()
        torch.testing.assert_allclose(logits_fwd.tolist(), logits_gen.tolist())

    def test_return_unprocessed_logit_scores(self):
        "Tests that the returned logits and scores are different, i.e. unprocessed vs processed scores"
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        text = "generate yes or no: "
        input_ids = tokenizer([text], return_tensors="pt").input_ids.to(torch_device)
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)

        outputs = model.generate(
            input_ids=input_ids,
            return_dict_in_generate=True,
            output_logits=True,
            output_scores=True,
            max_new_tokens=3,
            do_sample=False,
            exponential_decay_length_penalty=(0, 4.6),
            bad_words_ids=[[0], [1], [2]],
        )

        for token_logits, token_scores in zip(outputs.logits, outputs.scores):
            self.assertFalse((token_logits == token_scores).all().item())

        # Without logits processor, logits and scores are identical
        outputs = model.generate(
            input_ids=input_ids,
            return_dict_in_generate=True,
            output_logits=True,
            output_scores=True,
            max_new_tokens=3,
            do_sample=False,
        )

        for token_logits, token_scores in zip(outputs.logits, outputs.scores):
            self.assertListEqual(token_logits.tolist(), token_scores.tolist())

    @slow
    @require_torch_multi_accelerator
    def test_assisted_decoding_in_different_accelerator(self):
        device_0 = f"{torch_device}:0" if torch_device != "cpu" else "cpu"
        device_1 = f"{torch_device}:1" if torch_device != "cpu" else "cpu"
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM").to(device_0)
        assistant = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM").to(
            device_1
        )
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")
        model.config.pad_token_id = tokenizer.eos_token_id
        assistant.config.pad_token_id = tokenizer.eos_token_id

        text = "Hello world"
        tokenized_inputs = tokenizer([text], return_tensors="pt")
        input_ids = tokenized_inputs.input_ids.to(torch_device)
        input_length = input_ids.shape[-1]

        out = model.generate(
            input_ids,
            assistant_model=assistant,
            max_new_tokens=20,
        )
        self.assertTrue(input_length <= out.shape[-1] <= input_length + 20)

    @slow
    @require_torch_accelerator
    def test_assisted_decoding_model_in_accelerator_assistant_in_cpu(self):
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM").to(
            torch_device
        )
        assistant = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM").to(
            "cpu"
        )
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")
        model.config.pad_token_id = tokenizer.eos_token_id
        assistant.config.pad_token_id = tokenizer.eos_token_id

        text = "Hello world"
        tokenized_inputs = tokenizer([text], return_tensors="pt")
        input_ids = tokenized_inputs.input_ids.to(torch_device)
        input_length = input_ids.shape[-1]

        out = model.generate(
            input_ids,
            assistant_model=assistant,
            max_new_tokens=20,
        )
        self.assertTrue(input_length <= out.shape[-1] <= input_length + 20)

    def test_special_tokens_fall_back_to_model_default(self):
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM").to(
            torch_device
        )
        test_bos_id = 50

        # Sanity-check: the model has a BOS token set, and the first generated token is a BOS token
        gen_output = model.generate()
        self.assertTrue(model.generation_config.bos_token_id is not None)
        self.assertTrue(model.generation_config.bos_token_id == gen_output[0, 0])

        # If we pass a generation config **with** a BOS token, `generate` will use it
        generation_config = GenerationConfig(bos_token_id=test_bos_id)
        gen_output = model.generate(generation_config=generation_config)
        self.assertFalse(model.generation_config.bos_token_id == gen_output[0, 0])
        self.assertTrue(generation_config.bos_token_id == gen_output[0, 0])
        self.assertTrue(test_bos_id == gen_output[0, 0])

        # If we pass a generation config **without** a BOS token, `generate` will fetch the BOS token from
        # `model.generation_config`
        generation_config = GenerationConfig(bos_token_id=None)
        gen_output = model.generate(generation_config=generation_config)
        self.assertTrue(model.generation_config.bos_token_id == gen_output[0, 0])
        self.assertFalse(test_bos_id == gen_output[0, 0])
        self.assertTrue(generation_config.bos_token_id is None)

        # Changing `model.generation_config` will affect fallback behavior
        model.generation_config.bos_token_id = test_bos_id
        gen_output = model.generate(generation_config=generation_config)
        self.assertTrue(model.generation_config.bos_token_id == gen_output[0, 0])
        self.assertTrue(test_bos_id == gen_output[0, 0])
        self.assertTrue(generation_config.bos_token_id is None)

    def test_speculative_decoding_equals_regular_decoding(self):
        draft_name = "double7/vicuna-68m"
        target_name = "Qwen/Qwen2-0.5B-Instruct"

        # TODO Matt: Slightly flaky (~1%) without set_seed - if anyone wants to do
        #            a deep dive on why, feel free!
        set_seed(42)
        draft_model = AutoModelForCausalLM.from_pretrained(draft_name)
        target_model = AutoModelForCausalLM.from_pretrained(target_name)

        assistant_tokenizer = AutoTokenizer.from_pretrained(draft_name)
        target_tokenizer = AutoTokenizer.from_pretrained(target_name)

        prompt_size = torch.randint(low=20, high=100, size=(1,))
        max_new_tokens = torch.randint(low=10, high=50, size=(1,))
        input_ids = (torch.rand(1, prompt_size[0]) * 100).to(int) + 50

        max_new_tokens_item = max_new_tokens[0].item()
        expected_out = target_model.generate(input_ids, do_sample=False, max_new_tokens=max_new_tokens_item)
        predicted_out = target_model.generate(
            input_ids,
            do_sample=False,
            max_new_tokens=max_new_tokens_item,
            assistant_model=draft_model,
            tokenizer=target_tokenizer,
            assistant_tokenizer=assistant_tokenizer,
        )

        self.assertEqual(expected_out.shape, predicted_out.shape)
        self.assertTrue((expected_out == predicted_out).all().item())

    @pytest.mark.generate
    @require_torch_multi_accelerator
    def test_generate_with_static_cache_multi_accelerator(self):
        """
        Tests if the static cache has been set correctly and if generate works correctly when we are using multi-acceleratorss.
        """
        # need to split manually as auto doesn't work well with unbalanced model
        device_map = {"model.embed_tokens": 0, "model.layers.0": 0, "model.layers.1": 1, "model.norm": 1, "lm_head": 0}
        model = AutoModelForCausalLM.from_pretrained(
            "hf-internal-testing/tiny-random-MistralForCausalLM", device_map=device_map
        )
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")

        text = "Hello world"
        tokenized_inputs = tokenizer([text], return_tensors="pt")
        input_ids = tokenized_inputs.input_ids.to(torch_device)

        generation_kwargs = {
            "max_new_tokens": 20,
            "cache_implementation": "static",
            "return_dict_in_generate": True,  # Required to return `past_key_values`
        }

        results = model.generate(input_ids, **generation_kwargs)
        self.assertTrue(isinstance(results.past_key_values, StaticCache))

        # check device of each layer
        keys_0 = results.past_key_values.layers[0].keys
        values_0 = results.past_key_values.layers[0].values
        self.assertTrue(keys_0.device == values_0.device == torch.device(0))

        keys_1 = results.past_key_values.layers[1].keys
        values_1 = results.past_key_values.layers[1].values
        self.assertTrue(keys_1.device == values_1.device == torch.device(1))

    @pytest.mark.generate
    @require_torch_multi_accelerator
    def test_generate_multi_accelerator_causal_mask(self):
        """
        Tests that cache position device doesn't clash with causal mask device when we are using multi-accelerators.
        In real life happens only when multimodal encoder size is big, so `embed_tokens` gets allocated to the next device.
        The error will be triggered whenever a bacthed input is used, so that `causal_mask` is actually prepared instead of
        being `None`.
        """
        # need to split manually as auto doesn't work well with unbalanced model
        device_map = {
            "visual": 0,
            "model.embed_tokens": 1,
            "model.layers.0": 1,
            "model.layers.1": 1,
            "model.rotary_emb": 1,
            "model.norm.weight": 1,
            "lm_head": 1,
        }
        model = AutoModelForImageTextToText.from_pretrained(
            "hf-internal-testing/tiny-random-Qwen2VLForConditionalGeneration", device_map=device_map
        )
        processor = AutoProcessor.from_pretrained("hf-internal-testing/tiny-random-Qwen2VLForConditionalGeneration")

        text = ["Hello world", "Today I went to the supermarket to buy"]
        inputs = processor(text=text, padding=True, return_tensors="pt").to(torch_device)
        _ = model.generate(**inputs, max_new_tokens=20)

    @pytest.mark.generate
    @require_torch_multi_accelerator
    def test_init_static_cache_multi_accelerator(self):
        """
        Tests if the static cache has been set correctly when we initialize it manually in a multi-accelerator setup.
        """
        # need to split manually as auto doesn't work well with unbalanced model
        device_map = {"model.embed_tokens": 0, "model.layers.0": 0, "model.layers.1": 1, "model.norm": 1, "lm_head": 0}
        model = AutoModelForCausalLM.from_pretrained(
            "hf-internal-testing/tiny-random-MistralForCausalLM", device_map=device_map
        )
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")

        text = "Hello world"
        tokenized_inputs = tokenizer([text], return_tensors="pt")
        input_ids = tokenized_inputs.input_ids.to(torch_device)

        generation_kwargs = {
            "max_new_tokens": 20,
            "return_dict_in_generate": True,  # Required to return `past_key_values`
        }

        # TODO: We need to raise a warning in case the cache is not set correctly
        # with self.assertRaisesRegex(ValueError, "If you are manually initializing the cache"):
        #     past_key_values = StaticCache(
        #         config=model.config, max_batch_size=1, max_cache_len=30, device=torch_device, dtype=model.dtype
        #     )
        #     results = model.generate(input_ids, past_key_values=past_key_values, **generation_kwargs)

        past_key_values = StaticCache(config=model.config, max_cache_len=30)
        results = model.generate(input_ids, past_key_values=past_key_values, **generation_kwargs)

        # check device of each layer
        keys_0 = results.past_key_values.layers[0].keys
        values_0 = results.past_key_values.layers[0].values
        self.assertTrue(keys_0.device == values_0.device == torch.device(0))

        keys_1 = results.past_key_values.layers[1].keys
        values_1 = results.past_key_values.layers[1].values
        self.assertTrue(keys_1.device == values_1.device == torch.device(1))

    def test_prepare_inputs_for_generation_decoder_llm(self):
        """Tests GenerationMixin.prepare_inputs_for_generation against expected usage with decoder-only llms."""

        config = AutoConfig.from_pretrained("hf-internal-testing/tiny-random-LlamaForCausalLM")
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-LlamaForCausalLM")
        model = model.to(torch_device)

        input_ids = torch.tensor([[1, 2, 3], [4, 5, 6]]).to(torch_device)
        attention_mask = torch.tensor([[1, 1, 1], [1, 1, 1]]).to(torch_device)
        dynamic_cache = DynamicCache(config=config)
        position_ids = torch.arange(input_ids.shape[-1], dtype=torch.long).to(torch_device)[None, ...]

        # 1. Sanity check: the model's `prepare_inputs_for_generation` comes from `GenerationMixin`
        self.assertTrue("GenerationMixin" in str(model.prepare_inputs_for_generation))

        # 2. If we pass input ids by themselves, we should get back the same input ids
        model_inputs = model.prepare_inputs_for_generation(input_ids)
        self.assertListEqual(model_inputs["input_ids"].tolist(), input_ids.tolist())

        # 3. `use_cache` (and other kwargs) are forwarded
        self.assertFalse("use_cache" in model_inputs)  # From the previous input, there is no `use_cache`
        model_inputs = model.prepare_inputs_for_generation(input_ids, use_cache=True, foo="bar")
        self.assertTrue(model_inputs["use_cache"] is True)
        self.assertEqual(model_inputs["foo"], "bar")

        # 4. We never discard data from input ids and expect it to be already slice
        init_input_ids = input_ids[:, :2]
        init_dynamic_cache = model(init_input_ids, past_key_values=dynamic_cache).past_key_values
        model_inputs = model.prepare_inputs_for_generation(
            input_ids,
            past_key_values=init_dynamic_cache,
            attention_mask=attention_mask,
            position_ids=position_ids,
        )
        self.assertTrue("past_key_values" in model_inputs)
        self.assertEqual(model_inputs["input_ids"].shape[-1], input_ids.shape[1])
        self.assertEqual(model_inputs["position_ids"].shape[-1], input_ids.shape[1])
        self.assertEqual(model_inputs["attention_mask"].shape[-1], input_ids.shape[1])

        # Data is sliced based on input ids length
        model_inputs = model.prepare_inputs_for_generation(
            init_input_ids,
            past_key_values=init_dynamic_cache,
            attention_mask=attention_mask,
            position_ids=position_ids,
        )
        self.assertTrue("past_key_values" in model_inputs)
        self.assertEqual(model_inputs["input_ids"].shape[-1], init_input_ids.shape[1])
        self.assertEqual(model_inputs["position_ids"].shape[-1], init_input_ids.shape[1])
        self.assertEqual(model_inputs["attention_mask"].shape[-1], 3)  # attn mask is never sliced, we need PAD mask

        # 5. If we pass a `static_cache`, the attention mask will be prepared as a static shape 4D mask
        max_cache_len = 10
        static_cache = StaticCache(config=config, max_cache_len=max_cache_len)
        static_cache = model(init_input_ids, past_key_values=static_cache).past_key_values
        model_inputs = model.prepare_inputs_for_generation(
            init_input_ids,
            past_key_values=static_cache,
            attention_mask=attention_mask,
        )
        self.assertTrue("past_key_values" in model_inputs)
        self.assertListEqual(
            list(model_inputs["attention_mask"].shape), [2, 1, init_input_ids.shape[1], max_cache_len]
        )

        # 6. We can also pass `inputs_embeds` as the embedded prompt. Because `generate` will append its result to
        # `input_ids` and the models will only accept one of the two inputs (`input_ids` or `inputs_embeds`), we
        # a) must use the cache b) must expect `input_ids` after the prompt is processed
        init_inputs_embeds = model.get_input_embeddings()(init_input_ids)

        # Prompt processing, i.e. first iteration
        model_inputs = model.prepare_inputs_for_generation(
            init_input_ids,
            inputs_embeds=init_inputs_embeds,
            is_first_iteration=True,
        )
        self.assertTrue(model_inputs["input_ids"] is None)
        self.assertTrue(model_inputs["inputs_embeds"] is not None)

        # After prompt processing, i.e. decoding loop
        model_inputs = model.prepare_inputs_for_generation(
            input_ids, past_key_values=dynamic_cache, inputs_embeds=init_inputs_embeds
        )
        self.assertTrue(model_inputs["input_ids"] is not None)
        self.assertTrue("inputs_embeds" not in model_inputs)

    def test_prepare_inputs_for_generation_encoder_decoder_llm(self):
        """
        Same as `test_prepare_inputs_for_generation_decoder_llm` but for encoder-decoder models. Main difference: we
        should look for `decoder_input_ids`, instead of `input_ids`.
        """
        model = AutoModelForSeq2SeqLM.from_pretrained("hf-internal-testing/tiny-random-t5")
        model = model.to(torch_device)

        # 1. Sanity check: the model's `prepare_inputs_for_generation` comes from `GenerationMixin`
        self.assertTrue("GenerationMixin" in str(model.prepare_inputs_for_generation))

        # 2. If we pass input ids by themselves, we should get back the same input ids -- with the encoder-decoder key
        decoder_input_ids = torch.tensor([[1, 2, 3], [4, 5, 6]]).to(torch_device)
        model_inputs = model.prepare_inputs_for_generation(decoder_input_ids)
        self.assertTrue(torch.all(model_inputs["decoder_input_ids"] == decoder_input_ids))

        # 3. If we pass the attention mask too, we will get back the attention mask. Encoder-decoder models usually
        # don't use `position_ids`
        decoder_attention_mask = torch.tensor([[1, 1, 1], [1, 1, 1]]).to(torch_device)
        model_inputs = model.prepare_inputs_for_generation(
            decoder_input_ids, decoder_attention_mask=decoder_attention_mask
        )
        self.assertTrue(torch.all(model_inputs["decoder_attention_mask"] == decoder_attention_mask))
        self.assertTrue("position_ids" not in model_inputs)

        # 4. `use_cache` (and other kwargs, like the encoder outputs) are forwarded
        self.assertFalse("use_cache" in model_inputs)  # From the previous input, there is no `use_cache`
        model_inputs = model.prepare_inputs_for_generation(decoder_input_ids, use_cache=True, encoder_outputs="foo")
        self.assertTrue(model_inputs["use_cache"] is True)
        self.assertTrue(model_inputs["encoder_outputs"] == "foo")
        # See the decoder-only test for more corner cases. The code is the same, so we don't repeat it here.

    @slow
    def test_assisted_generation_early_exit(self):
        """
        Tests that assisted generation with early exit works as expected. Under the hood, this has complex cache
        manipulation, which will cause the test to fail if something goes wrong there.
        """
        expected_output = "Alice and Bob are playing a game of poker. Alice has a pair of 8s and Bob has a pair"

        prompt = "Alice and Bob"
        checkpoint = "facebook/layerskip-llama3.2-1B"

        tokenizer = AutoTokenizer.from_pretrained(checkpoint)
        inputs = tokenizer(prompt, return_tensors="pt").to(torch_device)

        model = AutoModelForCausalLM.from_pretrained(checkpoint).to(torch_device)
        with sdpa_kernel([SDPBackend.EFFICIENT_ATTENTION, SDPBackend.MATH]):
            original_outputs = model.generate(**inputs, do_sample=False, max_new_tokens=20)
            original_decoded = tokenizer.batch_decode(original_outputs, skip_special_tokens=True)
            self.assertEqual(original_decoded, [expected_output])

            outputs_assisted = model.generate(**inputs, assistant_early_exit=4, do_sample=False, max_new_tokens=20)
            decoded_assisted = tokenizer.batch_decode(outputs_assisted, skip_special_tokens=True)
            self.assertEqual(decoded_assisted, [expected_output])

    @slow
    def test_beam_search_advanced_stopping_criteria(self):
        """
        Tests that beam search works with a stopping criteria that is not max length or EOS token. Prior to the beam
        search vectorization PR (#35802), beam search was not accepting other stopping criteria. Test inspired on
        the original issue (#34843).
        """
        tokenizer = AutoTokenizer.from_pretrained("Qwen/Qwen2.5-0.5B-Instruct")
        model = AutoModelForCausalLM.from_pretrained("Qwen/Qwen2.5-0.5B-Instruct").to(torch_device)

        prompt = (
            "Natalia sold clips to 48 of her friends in April, and then she sold half as many clips in May. "
            "How many clips did Natalia sell altogether in April and May?"
        )
        tokens = tokenizer(prompt, return_tensors="pt").to(torch_device)
        generation_config = GenerationConfig(num_beams=3, do_sample=False, length_penalty=1.0, max_new_tokens=100)

        # This particular prompt should result in a ":" being present in the answer
        out = model.generate(**tokens, generation_config=generation_config, tokenizer=tokenizer)
        output_text = tokenizer.decode(out[0], skip_special_tokens=True)
        last_non_special_token_decoded = tokenizer.decode(out[out != tokenizer.pad_token_id][-1])
        self.assertTrue(":" in output_text)
        self.assertFalse(":" in output_text[-5:])
        self.assertFalse(":" in last_non_special_token_decoded)

        # Adding an advanced stopping criteria: text generation should stop when a ":" is generated.
        # Note that:
        # 1 - the text up to ":" doesn't have to be the same, it can belong to a different beam
        # 2 - ":" may not be the last char, but it must be in the last non-special token
        generation_config.stop_strings = ":"
        out = model.generate(**tokens, generation_config=generation_config, tokenizer=tokenizer)
        output_text = tokenizer.decode(out[0], skip_special_tokens=True)
        last_non_special_token_decoded = tokenizer.decode(out[out != tokenizer.pad_token_id][-1])
        self.assertTrue(":" in output_text)
        self.assertTrue(":" in output_text[-5:])
        self.assertTrue(":" in last_non_special_token_decoded)

    def test_validate_generation_inputs(self):
        """Tests validation of inputs to `generate`"""
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-t5")
        model = AutoModelForSeq2SeqLM.from_pretrained("hf-internal-testing/tiny-random-t5")

        encoder_input_str = "Hello world"
        input_ids = tokenizer(encoder_input_str, return_tensors="pt").input_ids

        # typos are quickly detected (the correct argument is `do_sample`)
        with self.assertRaisesRegex(ValueError, "do_samples"):
            model.generate(input_ids, do_samples=True)

        # arbitrary arguments that will not be used anywhere are also not accepted
        with self.assertRaisesRegex(ValueError, "foo"):
            fake_model_kwargs = {"foo": "bar"}
            model.generate(input_ids, **fake_model_kwargs)

        # however, valid model_kwargs are accepted
        valid_model_kwargs = {"attention_mask": torch.tensor(np.zeros_like(input_ids))}
        model.generate(input_ids, **valid_model_kwargs)

    def test_custom_logits_processor(self):
        """Tests that custom logits processors can be used in `generate`, and that redundant arguments are caught."""
        bart_tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-bart")
        article = """Justin Timberlake and Jessica Biel, welcome to parenthood."""
        bart_model = AutoModelForSeq2SeqLM.from_pretrained("hf-internal-testing/tiny-random-bart")
        input_ids = bart_tokenizer(article, return_tensors="pt").input_ids

        logits_processor = LogitsProcessorList()
        logits_processor.append(MinLengthLogitsProcessor(min_length=10, eos_token_id=0))

        # it should not be allowed to both define `min_length` via kwargs and `logits_processor` list
        logger = logging.get_logger("transformers.generation.utils")
        logger.warning_once.cache_clear()
        with CaptureLogger(logger) as cl:
            bart_model.generate(input_ids, logits_processor=logits_processor, min_length=10)
        self.assertTrue(
            "custom logits processor of type <class 'transformers.generation.logits_process.MinLengthLogitsProcessor'> has been passed to `.generate()`, but it was also created in `.generate()"
            in cl.out
        )

        bart_model.generate(input_ids, logits_processor=logits_processor)

    def test_transition_scores_greedy_search(self):
        """Test that `compute_transition_scores` is working as expected with gready search"""
        articles = ["Justin Timberlake", "Michael Phelps"]
        tokenizer = AutoTokenizer.from_pretrained("distilbert/distilgpt2", padding_side="left")
        tokenizer.pad_token = tokenizer.eos_token

        model = AutoModelForCausalLM.from_pretrained("distilbert/distilgpt2")
        model.generation_config.eos_token_id = None
        input_ids = tokenizer(articles, return_tensors="pt", padding=True).input_ids
        model = model.to(torch_device)
        input_ids = input_ids.to(torch_device)

        outputs = model.generate(
            input_ids=input_ids,
            max_new_tokens=5,
            pad_token_id=tokenizer.eos_token_id,
            return_dict_in_generate=True,
            output_scores=True,
        )

        transition_scores = model.compute_transition_scores(outputs.sequences, outputs.scores)
        transition_scores = transition_scores.cpu().numpy()

        expected_scores = np.array(
            [
                [-57.8844, -60.45698, -70.16364, -65.50791, -66.35648],
                [-54.417572, -60.216614, -62.661243, -58.621933, -58.298683],
            ]
        )
        self.assertTrue(np.allclose(transition_scores, expected_scores, atol=1e-3))

    def test_transition_scores_greedy_search_normalized(self):
        """
        Test that `compute_transition_scores` is working as expected with gready search, with `normalize_logits=True`
        """
        articles = ["Justin Timberlake", "Michael Phelps"]
        tokenizer = AutoTokenizer.from_pretrained("distilbert/distilgpt2", padding_side="left")
        tokenizer.pad_token = tokenizer.eos_token

        model = AutoModelForCausalLM.from_pretrained("distilbert/distilgpt2")
        model.generation_config.eos_token_id = None
        input_ids = tokenizer(articles, return_tensors="pt", padding=True).input_ids
        model = model.to(torch_device)
        input_ids = input_ids.to(torch_device)

        outputs = model.generate(
            input_ids=input_ids,
            max_new_tokens=5,
            pad_token_id=tokenizer.eos_token_id,
            return_dict_in_generate=True,
            output_scores=True,
        )

        transition_scores = model.compute_transition_scores(outputs.sequences, outputs.scores, normalize_logits=True)
        transition_scores = transition_scores.cpu().numpy()

        expected_scores = np.array(
            [
                [-2.538938, -2.2694316, -2.1580915, -1.572299, -2.6719835],
                [-1.8826028, -2.2461371, -1.7556462, -2.9644494, -1.7996008],
            ]
        )
        self.assertTrue(np.allclose(transition_scores, expected_scores, atol=1e-3))

    def test_transition_scores_beam_search_encoder_decoder(self):
        """
        Test that `compute_transition_scores` is working as expected with beam search and encoder-decoder models
        """
        articles = [
            "Justin Timberlake and Jessica Biel, welcome to parenthood.",
            "Michael Phelps is arguably the most decorated Olympian of all time.",
        ]
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-bart")
        model = AutoModelForSeq2SeqLM.from_pretrained("hf-internal-testing/tiny-random-bart")
        input_ids = tokenizer(articles, return_tensors="pt", padding=True).input_ids
        model = model.to(torch_device)
        input_ids = input_ids.to(torch_device)

        outputs = model.generate(
            input_ids=input_ids,
            max_length=10,
            num_beams=4,
            num_return_sequences=2,
            eos_token_id=None,
            return_dict_in_generate=True,
            output_scores=True,
            length_penalty=0.0,
        )

        transition_scores = model.compute_transition_scores(outputs.sequences, outputs.scores, outputs.beam_indices)
        transition_scores = transition_scores.cpu().numpy()
        outputs.sequences_scores = outputs.sequences_scores.cpu().numpy()

        self.assertTrue(np.allclose(np.sum(transition_scores, axis=-1), outputs.sequences_scores, atol=1e-3))

    def test_transition_scores_beam_search_encoder_decoder_with_eos(self):
        """
        Test that `compute_transition_scores` is working as expected with beam search and encoder-decoder models, when
        an EOS token is defined
        """
        articles = [
            "Justin Timberlake and Jessica Biel, welcome to parenthood.",
            "Michael Phelps is arguably the most decorated Olympian of all time.",
        ]
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-bart")

        model = AutoModelForSeq2SeqLM.from_pretrained("hf-internal-testing/tiny-random-bart")
        input_ids = tokenizer(articles, return_tensors="pt", padding=True).input_ids
        model = model.to(torch_device)
        input_ids = input_ids.to(torch_device)

        outputs = model.generate(
            input_ids=input_ids,
            max_length=10,
            num_beams=4,
            num_return_sequences=2,
            return_dict_in_generate=True,
            output_scores=True,
            length_penalty=0.0,
        )

        transition_scores = model.compute_transition_scores(outputs.sequences, outputs.scores, outputs.beam_indices)
        transition_scores = transition_scores.cpu().numpy()
        outputs.sequences_scores = outputs.sequences_scores.cpu().numpy()

        self.assertTrue(np.allclose(np.sum(transition_scores, axis=-1), outputs.sequences_scores, atol=1e-3))

    def test_transition_scores_beam_search_decoder_only(self):
        """
        Test that `compute_transition_scores` is working as expected with beam search and decoder-only models
        """
        articles = [
            "Justin Timberlake",
            "Michael Phelps",
        ]
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        tokenizer.pad_token = tokenizer.eos_token

        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        input_ids = tokenizer(articles, return_tensors="pt", padding=True).input_ids
        model = model.to(torch_device)
        input_ids = input_ids.to(torch_device)

        outputs = model.generate(
            input_ids=input_ids,
            max_length=10,
            num_beams=4,
            num_return_sequences=2,
            pad_token_id=tokenizer.eos_token_id,
            eos_token_id=None,
            return_dict_in_generate=True,
            output_scores=True,
            length_penalty=0.0,
        )

        transition_scores = model.compute_transition_scores(outputs.sequences, outputs.scores, outputs.beam_indices)
        transition_scores = transition_scores.cpu().numpy()
        outputs.sequences_scores = outputs.sequences_scores.cpu().numpy()

        self.assertTrue(np.allclose(np.sum(transition_scores, axis=-1), outputs.sequences_scores, atol=1e-3))

    @slow
    def test_transition_scores_early_stopping(self):
        """
        Test that `compute_transition_scores` is working as expected with beam search and early stopping

        This is an aggressive test that makes sure that `beam_search's`
        transition scores are computed correctly for varying `num_return_sequences`, `num_beams` and `batch_size > 1`
        2 x input_ids for "question: How are you? \n context: I had a long day, "
        """
        input_ids = torch.tensor(2 * [[822, 10, 571, 33, 25, 58, 2625, 10, 27, 141, 3, 9, 307, 239, 6, 1]])
        model = AutoModelForSeq2SeqLM.from_pretrained("google-t5/t5-small")
        model = model.to(torch_device)
        input_ids = input_ids.to(torch_device)

        outputs = model.generate(
            input_ids,
            max_length=10,
            return_dict_in_generate=True,
            output_scores=True,
            forced_eos_token_id=model.config.eos_token_id,
            num_beams=4,
            do_sample=False,
            num_return_sequences=3,
            length_penalty=0.0,
        )

        transition_scores = model.compute_transition_scores(
            sequences=outputs.sequences, scores=outputs.scores, beam_indices=outputs.beam_indices
        )
        transition_scores = transition_scores.cpu().numpy()
        outputs.sequences_scores = outputs.sequences_scores.cpu().numpy()

        self.assertTrue(np.allclose(np.sum(transition_scores, axis=-1), outputs.sequences_scores))

    def test_encoder_decoder_generate_attention_mask(self):
        """
        Test that `generate` automatically creates the correct `attention_mask` for encoder-decoder models (which
        has a different keyword)
        """
        articles = ["Timberlake", "Jessica Biel, welcome to parenthood among other things"]
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-bart")
        model = AutoModelForSeq2SeqLM.from_pretrained("hf-internal-testing/tiny-random-bart")
        model = model.to(torch_device)
        model.config.eos_token_id = None

        input_ids = tokenizer(articles[0], return_tensors="pt").to(torch_device).input_ids
        input_ids_batched = tokenizer(articles, padding=True, return_tensors="pt").to(torch_device).input_ids

        # need extreme generation values here to force this test
        # to fail when `attention_mask` is not correctly treated in generate
        generate_kwargs = {
            "return_dict_in_generate": True,
            "output_scores": True,
            "max_length": 50,
            "num_beams": 5,
            "num_return_sequences": 5,
        }

        output_sequences_batched = model.generate(input_ids=input_ids_batched, **generate_kwargs)
        output_sequences = model.generate(input_ids=input_ids, **generate_kwargs)

        batched_out = output_sequences_batched.sequences_scores.cpu().numpy()
        out = output_sequences.sequences_scores.cpu().numpy()

        diff = np.abs(np.sum(batched_out[:5]) - np.sum(out))
        self.assertLess(diff, 5e-4)

    def test_generate_input_ids_as_kwarg(self):
        """Test that `input_ids` work equally as a positional and keyword argument in decoder-only models"""
        article = "I need input_ids to generate"
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        input_ids = tokenizer(article, return_tensors="pt").input_ids
        model = model.to(torch_device)
        input_ids = input_ids.to(torch_device)

        output_sequences_kwargs = model.generate(input_ids=input_ids, max_length=15)
        output_sequences = model.generate(input_ids, max_length=15)
        output_sequences_kwargs = output_sequences_kwargs.cpu().numpy()
        output_sequences = output_sequences.cpu().numpy()

        self.assertTrue(np.array_equal(output_sequences, output_sequences_kwargs))
        self.assertEqual(output_sequences.shape, (1, 15))

    def test_generate_input_ids_as_encoder_kwarg(self):
        """Test that `input_ids` work equally as a positional and keyword argument in encoder-decoder models"""
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-bart")
        model = AutoModelForSeq2SeqLM.from_pretrained("hf-internal-testing/tiny-random-bart")
        model = model.to(torch_device)
        model.generation_config.eos_token_id = None

        article = "Justin Timberlake and Jessica Biel, welcome to parenthood."
        input_ids = tokenizer(article, return_tensors="pt").to(torch_device).input_ids

        output_sequences_kwargs = model.generate(input_ids=input_ids, max_length=5)
        output_sequences = model.generate(input_ids, max_length=5)
        output_sequences_kwargs = output_sequences_kwargs.cpu().numpy()
        output_sequences = output_sequences.cpu().numpy()

        self.assertTrue(np.array_equal(output_sequences, output_sequences_kwargs))
        self.assertEqual(output_sequences.shape, (1, 5))

    def test_generate_inputs_and_encoder_kwargs(self):
        """
        Test that an exception is thrown if the main tensor (`input_ids` in LLMs) is passed as both a positional and
        keyword argument
        """
        article = "I need input_ids to generate"
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        input_ids = tokenizer(article, return_tensors="pt").input_ids
        with self.assertRaises(ValueError):
            model.generate(input_ids, input_ids=input_ids, max_length=5)

    def test_generate_too_many_encoder_kwargs(self):
        """Test that passing redundant inputs results in an exception (`input_ids` and `inputs_embeds` in LLMs)"""
        article = "I need input_ids to generate"
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-bart")
        model = AutoModelForSeq2SeqLM.from_pretrained("hf-internal-testing/tiny-random-bart")
        input_ids = tokenizer(article, return_tensors="pt").input_ids
        with self.assertRaises(ValueError):
            model.generate(input_ids=input_ids, inputs_embeds=input_ids, max_length=10)

    def test_eos_token_id_int_and_list_greedy_search(self):
        """Test that `generate` can handle multiple EOS tokens"""
        generation_kwargs = {
            "do_sample": False,
            "num_beams": 1,
        }
        expectation = 13

        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        text = """Hello, my dog is cute and"""
        tokens = tokenizer(text, return_tensors="pt")
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        model = model.to(torch_device)
        tokens = tokens.to(torch_device)

        eos_token_id = 873
        generated_tokens = model.generate(**tokens, eos_token_id=eos_token_id, **generation_kwargs)
        self.assertTrue(expectation == len(generated_tokens[0]))

        eos_token_id = [873, 198]
        generated_tokens = model.generate(**tokens, eos_token_id=eos_token_id, **generation_kwargs)
        self.assertTrue(expectation == len(generated_tokens[0]))

    def test_generate_vision2text_conditioning(self):
        """Test that `decoder_input_ids` can be used to condition the generation in vision-to-text models"""
        pixel_values = floats_tensor((2, 3, 30, 30))
        conditioning_input = torch.tensor([[10], [10]])  # this should be the 2nd output token, after the BOS token
        model = AutoModelForImageTextToText.from_pretrained(
            "hf-internal-testing/tiny-random-VisionEncoderDecoderModel-vit-gpt2"
        )
        pixel_values = pixel_values.to(torch_device)
        model = model.to(torch_device)
        conditioning_input = conditioning_input.to(torch_device)

        # we can condition on decoder_input_ids (expected decoder input) and input_ids (which we pipe internally as
        # decoder_input_ids, if the encoder is not a model with text input)
        output_sequences_decoder_input_ids = model.generate(
            pixel_values, max_length=5, decoder_input_ids=conditioning_input
        )
        output_sequences_input_ids = model.generate(pixel_values, max_length=5, input_ids=conditioning_input)
        output_sequences_decoder_input_ids = output_sequences_decoder_input_ids.cpu().numpy()
        output_sequences_input_ids = output_sequences_input_ids.cpu().numpy()
        conditioning_input = conditioning_input.cpu().numpy()

        self.assertTrue(np.array_equal(output_sequences_decoder_input_ids, output_sequences_input_ids))
        self.assertTrue(np.array_equal(output_sequences_decoder_input_ids[:, 1:2], conditioning_input))

    @pytest.mark.generate
    def test_load_generation_config_from_text_subconfig(self):
        """
        Tests that generation config is be loaded from model's `text_config` when not present
        in the model repo. We should infer the text config correctly and re-use special tokens
        for generation. See https://github.com/huggingface/transformers/issues/42794
        """
        model = AutoModelForImageTextToText.from_pretrained(
            "hf-internal-testing/tiny-random-LlavaForConditionalGeneration-no-generation-config",
            device_map=torch_device,
        )
        self.assertEqual(model.generation_config.eos_token_id, None)
        self.assertEqual(model.generation_config.bos_token_id, None)
        self.assertEqual(model.generation_config.pad_token_id, 1)

    @slow
    @require_torch_accelerator
    def test_cache_device_map_with_vision_layer_device_map(self):
        """
        Test that the cache device map is correctly set when the vision layer has a device map. Regression test for
        #36942
        """
        # gemma 3 uses hybrid cache, which can be compiled -> needs a device map at allocation time
        model_id = "google/gemma-3-4b-it"

        # important part of this device map: the `.layers.` pattern is NOT present in the decoder
        device_map = {
            "vision_tower.vision_model.embeddings": 0,
            "vision_tower.vision_model.encoder.layers.0": 0,
            "vision_tower.vision_model.encoder.layers.1": 0,
            "vision_tower.vision_model.encoder.layers.2": 0,
            "vision_tower.vision_model.encoder.layers.3": 0,
            "vision_tower.vision_model.encoder.layers.4": 0,
            "vision_tower.vision_model.encoder.layers.5": 0,
            "vision_tower.vision_model.encoder.layers.6": 0,
            "vision_tower.vision_model.encoder.layers.7": 0,
            "vision_tower.vision_model.encoder.layers.8": 0,
            "vision_tower.vision_model.encoder.layers.9": 0,
            "vision_tower.vision_model.encoder.layers.10": 0,
            "vision_tower.vision_model.encoder.layers.11": 0,
            "vision_tower.vision_model.encoder.layers.12": 0,
            "vision_tower.vision_model.encoder.layers.13": 0,
            "vision_tower.vision_model.encoder.layers.14": "cpu",
            "vision_tower.vision_model.encoder.layers.15": "cpu",
            "vision_tower.vision_model.encoder.layers.16": "cpu",
            "vision_tower.vision_model.encoder.layers.17": "cpu",
            "vision_tower.vision_model.encoder.layers.18": "cpu",
            "vision_tower.vision_model.encoder.layers.19": "cpu",
            "vision_tower.vision_model.encoder.layers.20": "cpu",
            "vision_tower.vision_model.encoder.layers.21": "cpu",
            "vision_tower.vision_model.encoder.layers.22": "cpu",
            "vision_tower.vision_model.encoder.layers.23": "cpu",
            "vision_tower.vision_model.encoder.layers.24": "cpu",
            "vision_tower.vision_model.encoder.layers.25": "cpu",
            "vision_tower.vision_model.encoder.layers.26": "cpu",
            "vision_tower.vision_model.post_layernorm": "cpu",
            "multi_modal_projector": "cpu",
            "language_model": "cpu",
        }

        model = AutoModelForImageTextToText.from_pretrained(model_id, device_map=device_map, dtype=torch.bfloat16)
        tokenizer = AutoTokenizer.from_pretrained(model_id)
        inputs = tokenizer(["This is a text input"], return_tensors="pt").to(model.device)

        # If the generate doesn't infer the DECODER device map correctly, this will fail
        _ = model.generate(**inputs, max_new_tokens=2, do_sample=False)

    @require_torch_accelerator
    @pytest.mark.torch_compile_test
    def test_cpu_offload_doesnt_compile(self):
        """Test that CPU offload doesn't trigger compilation"""
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")
        tokenized_inputs = tokenizer(["Hello world"], return_tensors="pt")
        generate_kwargs = {"max_new_tokens": 3, "cache_implementation": "static"}

        # Sanity check: if we don't specify a device map, the model will get compiled
        model_gpu = AutoModelForCausalLM.from_pretrained(
            "hf-internal-testing/tiny-random-MistralForCausalLM", device_map="auto"
        )
        input_ids = tokenized_inputs.input_ids.to(model_gpu.device)
        _ = model_gpu.generate(input_ids, **generate_kwargs)
        self.assertTrue(hasattr(model_gpu, "_compiled_call"))

        # If we specify a device map, the model will not be compiled
        # (as of April 2025, compiling with CPU offload results in a crash)
        device_map = {
            "model.embed_tokens": 0,
            "model.layers.0": 0,
            "model.layers.1": "cpu",
            "model.norm": "cpu",
            "lm_head": 0,
        }
        model_cpu = AutoModelForCausalLM.from_pretrained(
            "hf-internal-testing/tiny-random-MistralForCausalLM", device_map=device_map
        )
        input_ids = tokenized_inputs.input_ids.to(model_cpu.device)
        _ = model_cpu.generate(input_ids, **generate_kwargs)
        self.assertFalse(hasattr(model_cpu, "_compiled_call"))

    def test_custom_generate_from_argument_in_generate(self):
        """Tests that the `custom_generate` argument is used when passed to `generate`"""
        model = AutoModelForCausalLM.from_pretrained(
            "hf-internal-testing/tiny-random-MistralForCausalLM", device_map="auto"
        )
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")
        model_inputs = tokenizer("Hello, world!", return_tensors="pt").to(model.device)
        # Note: `transformers-community/custom_generate_example` has a custom decoding method with a `left_padding`
        # argument (int), which prepends as many pad tokens.
        gen_out = model.generate(
            **model_inputs,
            left_padding=5,
            max_new_tokens=5,
            custom_generate="transformers-community/custom_generate_example",
            trust_remote_code=True,
        )
        text_output = tokenizer.decode(gen_out[0])
        self.assertTrue(text_output.startswith("<unk><unk><unk><unk><unk>"))  # <unk> is the pad token

    def test_custom_generate_from_model_repo_with_custom_generate_code(self):
        """
        Tests that models from model repos containing custom generation code override `generate` with the custom code
        """
        model = AutoModelForCausalLM.from_pretrained(
            "transformers-community/custom_generate_example", device_map="auto", trust_remote_code=True
        )
        generate_signature = inspect.signature(model.generate)
        # `left_padding` is a custom argument, doesn't exist in the base `generate` method
        self.assertTrue(generate_signature.parameters.get("left_padding"))

    def test_custom_generate_bad_requirements(self):
        """Tests that we check the `requirements.txt` file from custom generation repos"""
        model = AutoModelForCausalLM.from_pretrained(
            "hf-internal-testing/tiny-random-MistralForCausalLM", device_map="auto"
        )
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")
        model_inputs = tokenizer("Hello, world!", return_tensors="pt").to(model.device)
        with self.assertRaises(ImportError):
            # Note: `transformers-community/custom_generate_bad_requirements` has a `requirements.txt` with
            # impossible requirements
            model.generate(
                **model_inputs,
                custom_generate="transformers-community/custom_generate_bad_requirements",
                trust_remote_code=True,
            )

    def test_custom_generate_requires_trust_remote_code(self):
        """Tests that `trust_remote_code` is required when using `custom_generate`"""
        model = AutoModelForCausalLM.from_pretrained(
            "hf-internal-testing/tiny-random-MistralForCausalLM", device_map="auto"
        )
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")
        model_inputs = tokenizer("Hello, world!", return_tensors="pt").to(model.device)
        with self.assertRaises(ValueError):
            model.generate(
                **model_inputs,
                max_new_tokens=10,
                trust_remote_code=False,
                custom_generate="transformers-community/custom_generate_example",
            )

    def test_custom_generate_local_directory(self):
        """Tests that custom_generate works with local directories containing importable relative modules"""
        with tempfile.TemporaryDirectory() as tmp_dir:
            custom_generate_dir = Path(tmp_dir) / "custom_generate"
            custom_generate_dir.mkdir()
            with open(custom_generate_dir / "generate.py", "w") as f:
                f.write("from .helper import ret_success\ndef generate(*args, **kwargs):\n    return ret_success()\n")
            with open(custom_generate_dir / "helper.py", "w") as f:
                f.write('def ret_success():\n    return "success"\n')
            model = AutoModelForCausalLM.from_pretrained(
                "hf-internal-testing/tiny-random-MistralForCausalLM", device_map="auto"
            )
            tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")
            model_inputs = tokenizer("Hello, world!", return_tensors="pt").to(model.device)
            value = model.generate(
                **model_inputs,
                custom_generate=str(tmp_dir),
                trust_remote_code=True,
            )
            assert value == "success"

    def test_custom_generate_local_directory_requires_trust_remote_code(self):
        """Tests that `trust_remote_code` is required for a local-directory `custom_generate` too (not
        just for Hub repos): otherwise a repository's `custom_generate/generate.py` would execute on
        load without any opt-in."""
        model = AutoModelForCausalLM.from_pretrained(
            "hf-internal-testing/tiny-random-MistralForCausalLM", device_map="auto"
        )
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")
        model_inputs = tokenizer("Hello, world!", return_tensors="pt").to(model.device)
        with tempfile.TemporaryDirectory() as tmp_dir:
            custom_generate_dir = Path(tmp_dir) / "custom_generate"
            custom_generate_dir.mkdir()
            with open(custom_generate_dir / "generate.py", "w") as f:
                f.write("def generate(*args, **kwargs):\n    return 'should_not_run'\n")
            with self.assertRaises(ValueError):
                model.generate(
                    **model_inputs,
                    max_new_tokens=10,
                    trust_remote_code=False,
                    custom_generate=str(tmp_dir),
                )

    def test_custom_generate_callable(self):
        """Tests that passing a callable to `custom_generate` executes the callable decoding loop"""
        model = AutoModelForCausalLM.from_pretrained(
            "hf-internal-testing/tiny-random-MistralForCausalLM", device_map="auto"
        )
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")
        model_inputs = tokenizer("Hello, world!", return_tensors="pt").to(model.device)

        def custom_loop(model, input_ids, logits_processor, stopping_criteria, generation_config, **model_kwargs):
            # Check that generate() correctly prepares the stopping criteria
            assert stopping_criteria[0].max_length == input_ids.shape[1] + 3
            return "callable_success"

        value = model.generate(
            **model_inputs,
            max_new_tokens=3,
            custom_generate=custom_loop,
        )
        self.assertEqual(value, "callable_success")

    @pytest.mark.generate
    def test_generate_can_restart_from_cache_and_new_tokens_only(self):
        """
        Test that we can continue generating from past key values, returned from a previous `generate` call, without
        the tokens that correspond to the cached part IF the `attention_mask` is the mask for the FULL sequence
        (including previous tokens)
        """
        model = AutoModelForCausalLM.from_pretrained(
            "hf-internal-testing/tiny-random-MistralForCausalLM", device_map="auto"
        )
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-MistralForCausalLM")

        initial_inputs = tokenizer("Hello, world!", return_tensors="pt").to(model.device)
        generate_kwargs = {
            "use_cache": True,
            "do_sample": False,
            "return_dict_in_generate": True,
            "output_scores": True,
        }

        truncated_outputs = model.generate(**initial_inputs, **generate_kwargs, max_new_tokens=2, min_new_tokens=2)
        full_outputs = model.generate(**initial_inputs, **generate_kwargs, max_new_tokens=4, min_new_tokens=4)

        device = initial_inputs["attention_mask"].device
        new_full_mask = torch.cat((initial_inputs["attention_mask"], torch.ones(1, 2, device=device)), dim=-1)

        # Check that we can restart from FULL sequence and get the same result
        full_sequence_inputs = copy.deepcopy(initial_inputs)
        full_sequence_inputs["input_ids"] = truncated_outputs.sequences
        full_sequence_inputs["attention_mask"] = new_full_mask
        full_sequence_inputs["past_key_values"] = copy.deepcopy(truncated_outputs.past_key_values)
        full_sequence_outputs = model.generate(
            **full_sequence_inputs, **generate_kwargs, max_new_tokens=2, min_new_tokens=2
        )

        # The two sets of generated text and past kv should be equal to each other
        if is_moe_model(model.config):
            atol = rtol = 1e-3
        else:
            atol = rtol = 1e-5
        assert_similar_generate_outputs(full_outputs, full_sequence_outputs, atol=atol, rtol=rtol)
        cache1, cache2 = full_outputs.past_key_values, full_sequence_outputs.past_key_values
        for idx in range(len(cache1)):
            if isinstance(cache1, EncoderDecoderCache):
                for subcache in ["self_attention_cache", "cross_attention_cache"]:
                    torch.testing.assert_close(
                        getattr(cache1, subcache).layers[idx].keys, getattr(cache2, subcache).layers[idx].keys
                    )
                    torch.testing.assert_close(
                        getattr(cache1, subcache).layers[idx].values, getattr(cache2, subcache).layers[idx].values
                    )
            else:
                torch.testing.assert_close(cache1.layers[idx].keys, cache2.layers[idx].keys)
                torch.testing.assert_close(cache1.layers[idx].values, cache2.layers[idx].values)

        # Now, check that we can do the same while only restarting from last tokens IF we pass the full mask
        single_token_inputs = copy.deepcopy(initial_inputs)
        single_token_inputs["input_ids"] = truncated_outputs.sequences[:, -1:]
        single_token_inputs["attention_mask"] = new_full_mask
        single_token_inputs["past_key_values"] = copy.deepcopy(truncated_outputs.past_key_values)
        single_token_outputs = model.generate(
            **single_token_inputs, **generate_kwargs, max_new_tokens=2, min_new_tokens=2
        )

        # Of course we get only the new tokens as outputs here, so slice before performing the check
        full_outputs["sequences"] = full_outputs["sequences"][:, -3:]
        assert_similar_generate_outputs(full_outputs, single_token_outputs, atol=atol, rtol=rtol)
        cache1, cache2 = full_outputs.past_key_values, single_token_outputs.past_key_values
        for idx in range(len(cache1)):
            if isinstance(cache1, EncoderDecoderCache):
                for subcache in ["self_attention_cache", "cross_attention_cache"]:
                    torch.testing.assert_close(
                        getattr(cache1, subcache).layers[idx].keys, getattr(cache2, subcache).layers[idx].keys
                    )
                    torch.testing.assert_close(
                        getattr(cache1, subcache).layers[idx].values, getattr(cache2, subcache).layers[idx].values
                    )
            else:
                torch.testing.assert_close(cache1.layers[idx].keys, cache2.layers[idx].keys)
                torch.testing.assert_close(cache1.layers[idx].values, cache2.layers[idx].values)

    @pytest.mark.generate
    @parameterized.expand(
        [
            ("transformers-community/dola", {"dola_layers": "low"}),
            ("transformers-community/contrastive-search", {"penalty_alpha": 0.6, "top_k": 4}),
            (
                "transformers-community/group-beam-search",
                {
                    "do_sample": False,
                    "num_beams": 2,
                    "num_beam_groups": 2,
                    "diversity_penalty": 2.0,
                    "length_penalty": 2.0,
                },
            ),
            (
                "transformers-community/constrained-beam-search",
                {"do_sample": False, "num_beams": 2, "force_words_ids": [[167, 168, 169]]},
            ),
        ]
    )
    def test_hub_gen_strategies(self, custom_generate, extra_kwargs):
        model = AutoModelForCausalLM.from_pretrained(
            "hf-internal-testing/tiny-random-MistralForCausalLM",
            device_map=torch_device,
            attn_implementation="eager",
        ).eval()
        model_inputs = {
            "input_ids": torch.tensor([[1, 22557, 28725, 1526, 28808]], device=torch_device),
            "attention_mask": torch.tensor([[1, 1, 1, 1, 1]], device=torch_device),
        }
        # Sets generation arguments such that:
        # a) no EOS is generated, to ensure generation doesn't break early
        # b) there are at least two forward passes in the main model, to ensure the input preparation of
        #    the main model is correct
        generation_kwargs = {
            "eos_token_id": -1,  # see a)
            "max_new_tokens": 4,  # see b)
            "num_beams": 1,
            "do_sample": True,
            "output_scores": True,
            "output_logits": True,
            "output_hidden_states": True,
            "output_attentions": True,
            "return_dict_in_generate": True,
            "use_cache": True,
            "trust_remote_code": True,
            "custom_generate": custom_generate,
        }
        generation_kwargs.update(extra_kwargs)
        set_seed(42)
        output = model.generate(**generation_kwargs, **model_inputs)
        self.assertEqual(output.sequences.shape, (1, 9))

    def test_model_generation_config_can_override_defaults(self):
        """Sanity check that the model samples, not ignoring the model's generation config"""
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-LlamaForCausalLM").eval()
        model = model.to(torch_device)

        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-LlamaForCausalLM")
        model_inputs = tokenizer(["Write a poem about the market crashing in summer"], return_tensors="pt")
        model_inputs = model_inputs.to(model.device)

        # Overwrite default value or sampling
        model.generation_config.max_new_tokens = 52
        output = model.generate(**model_inputs, do_sample=False)

        EXPECTED_TEXT = 'Write a poem about the market crashing in summer wed digassethrte forec heav dent Var américaine dealing substr energcalc Christmas spé mak夢project askspush speech VBA sufficientjoint február retr Ostilingoser mehrere Mathemat jaarєдна Culturalomas prayerRAY gather ули Senate turn Publicterm cruel),( hardly virt Atlasisie mehrere Mathemat jaar'  # fmt: skip
        output = tokenizer.decode(output[0], skip_special_tokens=True)
        self.assertEqual(output, EXPECTED_TEXT)


@require_torch
class TokenHealingTestCase(unittest.TestCase):
    @parameterized.expand(
        [
            ("url", 'The link is <a href="http:', 'The link is <a href="http://'),
            # aggressive_healing: "http" shouldn't be replaced with "https"
            ("aggressive_healing", 'The link is <a href="http', 'The link is <a href="http'),
            ("trailing_whitespace", "I read a book about ", "I read a book about"),
            ("nothing_to_heal", "I read a book about", "I read a book about"),
            ("single_token", "I", "I"),
            ("empty_prompt", "", ""),
        ]
    )
    def test_prompts(self, name, input, expected):
        model_name_or_path = "distilbert/distilgpt2"
        tokenizer = AutoTokenizer.from_pretrained(model_name_or_path, use_fast=True)
        completion_model = AutoModelForCausalLM.from_pretrained(
            model_name_or_path,
            device_map="auto",
            trust_remote_code=False,
            revision="main",
            use_cache=True,
        )

        """
        tokenizer.pad_token value can be empty but it is required in the latter codes
        so assigned it here with eos_token
		"""
        tokenizer.pad_token = tokenizer.eos_token

        input_ids = tokenizer(input, return_tensors="pt").input_ids.to(completion_model.device)

        healed_ids = completion_model.heal_tokens(input_ids, tokenizer=tokenizer)
        predicted = tokenizer.decode(healed_ids[0], skip_special_tokens=True)
        predicted = predicted.lstrip()

        self.assertEqual(predicted, expected)

    def test_generate_from_inputs_embeds_with_bos_token_id_is_none(self):
        article = "Today a dragon flew over Paris."
        model = AutoModelForCausalLM.from_pretrained("hf-internal-testing/tiny-random-gpt2").to(torch_device)
        tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/tiny-random-gpt2")
        input_ids = tokenizer(article, return_tensors="pt").input_ids.to(torch_device)
        inputs_embeds = model.get_input_embeddings()(input_ids)

        model.generate(inputs_embeds=inputs_embeds, max_length=20, bos_token_id=None)

        # bos_token_id is required when no input ids nor inputs_embeds is passed
        with self.assertRaises(ValueError):
            model.generate(max_length=20, bos_token_id=None)


class TestAssistedCandidateGeneratorDifferentTokenizers(unittest.TestCase):
    def test_no_intersection(self):
        prompt = np.array([[1, 2, 3]])
        prompt_plus_new_tokens = np.array([[4, 5, 6]])
        result = AssistedCandidateGeneratorDifferentTokenizers._get_tokens_diag(prompt, prompt_plus_new_tokens)
        self.assertEqual(result, (None, None, None))

    def test_complete_overlap(self):
        prompt = np.array([[1, 2, 3]])
        prompt_plus_new_tokens = np.array([[1, 2, 3, 4, 5]])
        discrep_length, new_tokens_only, discrep_only = AssistedCandidateGeneratorDifferentTokenizers._get_tokens_diag(
            prompt, prompt_plus_new_tokens
        )
        self.assertEqual(discrep_length, 0)
        np.testing.assert_array_equal(new_tokens_only, np.array([[4, 5]]))
        np.testing.assert_array_equal(discrep_only, np.array([[]]))

    def test_partial_overlap(self):
        prompt = np.array([[1, 2, 3]])
        prompt_plus_new_tokens = np.array([[2, 3, 4, 5]])
        discrep_length, new_tokens_only, discrep_only = AssistedCandidateGeneratorDifferentTokenizers._get_tokens_diag(
            prompt, prompt_plus_new_tokens
        )
        self.assertEqual(discrep_length, 0)
        np.testing.assert_array_equal(new_tokens_only, np.array([[4, 5]]))
        np.testing.assert_array_equal(discrep_only, np.array([[]]))

    def test_no_new_tokens(self):
        prompt = np.array([[1, 2, 3]])
        prompt_plus_new_tokens = np.array([[1, 2, 3]])
        discrep_length, new_tokens_only, discrep_only = AssistedCandidateGeneratorDifferentTokenizers._get_tokens_diag(
            prompt, prompt_plus_new_tokens
        )
        self.assertEqual(discrep_length, 0)
        np.testing.assert_array_equal(new_tokens_only, np.array([[]]))
        np.testing.assert_array_equal(discrep_only, np.array([[]]))


class TestAssistedCandidateGeneratorUpdateStrategy(unittest.TestCase):
    def setUp(self):
        checkpoint = "EleutherAI/pythia-160m-deduped"
        self.assistant_model = AutoModelForCausalLM.from_pretrained(checkpoint)
        self.assistant_model.generation_config.assistant_confidence_threshold = 0.4
        self.model_kwargs = {}
        self.input_ids = torch.randint(1, 10, (1, 9))
        self.candidate_generator = AssistedCandidateGenerator(
            input_ids=self.input_ids,
            assistant_model=self.assistant_model,
            generation_config=self.assistant_model.generation_config,
            model_kwargs=self.model_kwargs,
        )
        self.candidate_generator.probs = [0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1]
        self.original_probs = self.candidate_generator.probs
        self.original_threshold = self.assistant_model.generation_config.assistant_confidence_threshold

    def assert_no_sklearn(self):
        with patch("transformers.generation.candidate_generator.is_sklearn_available", lambda: False):
            self.candidate_generator.update_candidate_strategy(self.input_ids, None, self.num_matches)
            self.assertEqual(self.candidate_generator.matches, self.original_matches)
            self.assertEqual(self.candidate_generator.probs, self.original_probs)
            self.assertEqual(
                self.candidate_generator.assistant_generation_config.assistant_confidence_threshold,
                self.original_threshold,
            )

    @parameterized.expand([(is_sklearn_available(),), (False,)])
    def test_update_candidate_strategy_no_matches_short(self, sklearn_available):
        self.original_matches = []
        self.candidate_generator.matches = self.original_matches
        self.num_matches = 0

        if sklearn_available:
            self.candidate_generator.update_candidate_strategy(self.input_ids, None, self.num_matches)
            self.assertEqual(self.candidate_generator.matches, [0])
            self.assertEqual(self.candidate_generator.probs, [0.9])
            self.assertEqual(self.candidate_generator.assistant_generation_config.assistant_confidence_threshold, 0.4)
        else:
            self.assert_no_sklearn()

    @parameterized.expand([(is_sklearn_available(),), (False,)])
    def test_update_candidate_strategy_with_mix_matches_3(self, sklearn_available):
        self.original_matches = [1, 0, 1, 0, 1]
        self.candidate_generator.matches = self.original_matches
        self.num_matches = 3
        if sklearn_available:
            self.candidate_generator.update_candidate_strategy(self.input_ids, None, self.num_matches)
            self.assertEqual(self.candidate_generator.matches, [1, 0, 1, 0, 1, 1, 1, 1, 0])
            self.assertEqual(self.candidate_generator.probs, [0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1])
            self.assertEqual(self.candidate_generator.assistant_generation_config.assistant_confidence_threshold, 0.2)
        else:
            self.assert_no_sklearn()

    @parameterized.expand([(is_sklearn_available(),), (False,)])
    def test_update_candidate_strategy_with_matches_4(self, sklearn_available):
        self.original_matches = [1, 1, 1, 1, 1]
        self.candidate_generator.matches = self.original_matches
        self.num_matches = 4
        if sklearn_available:
            self.candidate_generator.update_candidate_strategy(self.input_ids, None, self.num_matches)
            self.assertEqual(self.candidate_generator.matches, [1, 1, 1, 1, 1, 1, 1, 1, 1])
            self.assertEqual(self.candidate_generator.probs, [0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1])
            self.assertEqual(self.candidate_generator.assistant_generation_config.assistant_confidence_threshold, 0.4)
        else:
            self.assert_no_sklearn()

    @parameterized.expand([(is_sklearn_available(),), (False,)])
    def test_update_candidate_strategy_with_matches_3(self, sklearn_available):
        self.original_matches = [1, 1, 1, 1, 1]
        self.candidate_generator.matches = self.original_matches
        self.num_matches = 3
        if sklearn_available:
            self.candidate_generator.update_candidate_strategy(self.input_ids, None, self.num_matches)
            self.assertEqual(self.candidate_generator.matches, [1, 1, 1, 1, 1, 1, 1, 1, 0])
            self.assertEqual(self.candidate_generator.probs, [0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1])
            self.assertEqual(self.candidate_generator.assistant_generation_config.assistant_confidence_threshold, 0.2)
        else:
            self.assert_no_sklearn()

    @parameterized.expand([(is_sklearn_available(),), (False,)])
    def test_update_candidate_strategy_with_matches_2(self, sklearn_available):
        self.original_matches = [1, 1, 1, 1, 1]
        self.candidate_generator.matches = self.original_matches
        self.num_matches = 2
        if sklearn_available:
            self.candidate_generator.update_candidate_strategy(self.input_ids, None, self.num_matches)
            self.assertEqual(self.candidate_generator.matches, [1, 1, 1, 1, 1, 1, 1, 0])
            self.assertEqual(self.candidate_generator.probs, [0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2])
            self.assertEqual(self.candidate_generator.assistant_generation_config.assistant_confidence_threshold, 0.3)
        else:
            self.assert_no_sklearn()

    @parameterized.expand([(is_sklearn_available(),), (False,)])
    def test_update_candidate_strategy_with_matches_1(self, sklearn_available):
        self.original_matches = [1, 1, 1, 1, 1]
        self.candidate_generator.matches = self.original_matches
        self.num_matches = 1
        if sklearn_available:
            self.candidate_generator.update_candidate_strategy(self.input_ids, None, self.num_matches)
            self.assertEqual(self.candidate_generator.matches, [1, 1, 1, 1, 1, 1, 0])
            self.assertEqual(self.candidate_generator.probs, [0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3])
            self.assertEqual(self.candidate_generator.assistant_generation_config.assistant_confidence_threshold, 0.4)
        else:
            self.assert_no_sklearn()


def _get_generate_outputs_mismatch_message(output_1, output_2, atol=1e-5, rtol=1e-5) -> str:
    # scores doesn't include data regarding decoder input tokens
    decoder_input_length = output_1.sequences.shape[1] - len(output_1.scores)
    output_matches = output_1.sequences == output_2.sequences
    has_matching_outputs = output_matches.all()
    if has_matching_outputs:
        return ""
    for batch_idx in range(output_1.sequences.shape[0]):
        batch_matches = output_matches[batch_idx]
        if batch_matches.all():
            continue
        first_mismatch_idx = batch_matches.int().argmin()  # gets the index of the first False
        first_mismatch_idx -= decoder_input_length
        output_1_first_mismatch_scores = output_1.scores[first_mismatch_idx][batch_idx]
        output_2_first_mismatch_scores = output_2.scores[first_mismatch_idx][batch_idx]
        has_matching_scores = torch.allclose(
            output_1_first_mismatch_scores, output_2_first_mismatch_scores, atol=atol, rtol=rtol
        )
        if not has_matching_scores:
            score_diff = (output_1_first_mismatch_scores - output_2_first_mismatch_scores).abs()
            max_diff = score_diff.max().item()
            mean_diff = score_diff.mean().item()
            num_mismatched_tokens = (~batch_matches).sum().item()
            total_tokens = batch_matches.numel()
            return (
                f"Generate outputs are not similar enough (atol={atol}, rtol={rtol}).\n"
                f"  Sequence mismatch: {num_mismatched_tokens}/{total_tokens} tokens differ "
                f"(first at position {first_mismatch_idx + decoder_input_length}).\n"
                f"  Batch index: {batch_idx}\n"
                f"  Token at mismatch — output_1: {output_1.sequences[batch_idx, first_mismatch_idx + decoder_input_length].item()}, "
                f"output_2: {output_2.sequences[batch_idx, first_mismatch_idx + decoder_input_length].item()}\n"
                f"  Score diff at first mismatch — max: {max_diff:.6e}, mean: {mean_diff:.6e}"
            )
    return ""


def has_similar_generate_outputs(output_1, output_2, atol=1e-5, rtol=1e-5) -> bool:
    """
    Returns a boolean indicating whether a pair of generate outputs are similar. Two `generate` call outputs are
    considered similar in the following situations:
    1. The sequences are the same
    2. The sequences are different, but the scores up to (and including) the first mismatch are nearly identical
    """
    return not _get_generate_outputs_mismatch_message(output_1, output_2, atol=atol, rtol=rtol)


def assert_similar_generate_outputs(output_1, output_2, atol=1e-5, rtol=1e-5):
    """
    Asserts that a pair of generate outputs are similar, with a descriptive error message on failure.

    Similar to `has_similar_generate_outputs`, but raises an assertion error on failure.
    """
    mismatch_message = _get_generate_outputs_mismatch_message(output_1, output_2, atol=atol, rtol=rtol)
    if mismatch_message:
        raise AssertionError(mismatch_message)
