#PODNAME: Dancer::Development::Integration
#ABSTRACT: guide for Dancer's core-team members

__END__

=pod

=encoding UTF-8

=head1 NAME

Dancer::Development::Integration - guide for Dancer's core-team members

=head1 VERSION

version 1.3131_0

=head1 DESCRIPTION

This documentation describes the procedure used for integrators to review and
merge contributions sent via pull-requests.

Every core-team member should read and apply the procedures described
here. This will allow for a better history and more consistency in our
ways of handling the (increasing number!) of pull requests.

=head1 TERMS

We will first define the most important terms used in this
documentation:

=over

=item * B<PR> 

Acronym for B<P>ull B<R>equest

=item * Contributor

A GitHub user who had forked and cloned the official Dancer's repo, and
who has sent a PR.

=item * Integration branch

This branch is the branch used to merge all contributions. This is a
git-flow convention. In Dancer, our integration branch is C<devel>.

As explained in L<Dancer::Development>, every PR should be based on
the integration branch. If not, this is enough to refuse the PR (it
makes the life of the integrator much harder if this is not the case).

=item * Integrator

A member of Dancer's core-team who is responsible for reviewing and
either rejecting the PR, or merging it into the integration branch.

=back

=head1 PROCEDURES

=head2 Processing a Pull Request

This procedure describes how an integrator should process a PR. 

Let's say the user I<$user> has sent a PR, he has followed the
instructions described in L<Dancer::Development> so his work is based
on the integration branch (C<devel>).

All the procedure described here is designed to avoid unnecessary
recursive-merge, in order to keep a clean and flat history in the
integration branch.

Of course, we could just pull from I<$user> into our C<devel> branch,
but this would shift the history because of recursive merge, most of
the time.

To avoid that, we're going to pull the commits of I<$user> into a
temporary branch, and then cherry-pick the commits we want.

In order to have a clean history, like the one we got with git-flow
when working on a feature, we're going to do that in a topic branch,
named C<review/$user>. Then, this branch will be merged into C<devel>
and we will just have to drop it.

First, we make sure we are in sync with C<origin/devel>

    git checkout devel
    git pull origin devel 

Then, from that branch we create a I<temp> sandbox

    git checkout -b temp

We pull here from I<$user>

    git pull <user repo> <pr/branch>

Here, either the pull was run as a fast-forward or as a recursive
merge. If we have a FF, we can forget about the I<temp> branch and do the
pull directly in C<devel>. If not, we'll have to cherry-pick the
commits by hand.

From devel, we first create the final C<review> branch:

    git checkout devel
    git checkout -b review/$user

Then we cherry-pick all the commits we want. To know them, we just
have to go into I<temp> and inspect the history (with C<git log>).

When we have the list of commits we want:

    for commit in C1 C2 C3 ... CN
    do
        git cherry-pick $commit
    done

(Another option is to use C<git rebase -i> to manually select the list
of commits to cherry-pick/rebase.)

Then we can review the code, do whatever we want, maybe add some
commits to change something.

When we're happy with the change set, we can merge into devel:

    git checkout devel
    git merge --no-ff review/$user

Note the C<--no-ff> switch is used to make sure we'll see a nice
commit named C<< Merge branch 'review/$user' into devel >>. This is on
purpose and mimic the behaviour of git-flow.

Your local C<devel> branch is now merged, and can be pushed to the
remote.

    $ git push origin devel

=head1 RELEASE CYCLES

We have one main release cycle. This is the release cycle based on the I<devel>
branch. We use this branch to build new releases, with new stuff all the new
shiny commits we want.

Those release are built with git-flow (with C<git-flow release>) and are then
uploaded to CPAN.

Since Dancer 1.2, we also have another parallel release cycle which is what we
call the I<frozen> branch. It's a maintenance-only release cycle. That branch is
created from the tag of the first release of a I<stable> version (namely a
release series with an even minor number).

This branch must be used only for bug-fixing the stable releases. Nothing new
should occur in that branch.

Let's take an example with Dancer 1.2003 and Dancer 1.3002.

=over 4

=item *

Dancer 1.2003 is the last stable release of Dancer. Its codebase is handled in
the I<frozen> branch, that has been created from the tag C<1.2000>.

=item *

Dancer 1.3002 is the last release of Dancer. As it belongs to a development
series, it can provide new features, code refactoring and deprecations. Its
codebase is handled by the integration branch, C<devel>.

=item * 

When a bug is found in 1.2xxx, it's fixed in the C<frozen> branch, and a new
release is built from here and then uploaded to CPAN.

=item *

Whenever the team wants to, they can release new versions of 1.3xxx from the
devel branch, using C<git-flow release start>.

=item *

When the team finds that the current state of devel (namely, the last version of
1.3xxx) is stable and mature enough. They can decide it will be the new stable
version.

Then, a release 1.4000_01 is built from devel, an upload is done to CPAN, and
when ready, the 1.40001 can be uploaded the same way.

From that moment, the master branch is merged into frozen in order to be able to
hotfix the frozen branch in the future.

It's now possible for the team to continue working on new stuff in devel,
bumping the version number to 1.5000_01

=back

=head1 AUTHOR

This documentation has been written by Alexis Sukrieh C<< <sukria@sukria.net> >>.

=head1 AUTHOR

Dancer Core Developers

=head1 COPYRIGHT AND LICENSE

This software is copyright (c) 2010 by Alexis Sukrieh.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

=cut
