# How to contribute #

We'd love to accept your patches and contributions to this project.  There are
a just a few small guidelines you need to follow.


## Contributor License Agreement ##

Contributions to any Google project must be accompanied by a Contributor
License Agreement.  This is not a copyright **assignment**, it simply gives
Google permission to use and redistribute your contributions as part of the
project.  Head over to <https://cla.developers.google.com/> to see your current
agreements on file or to sign a new one.

You generally only need to submit a CLA once, so if you've already submitted one
(even if it was for a different project), you probably don't need to do it
again.


## Submitting a patch ##

  1. It's generally best to start by opening a new issue describing the bug or
     feature you're intending to fix.  Even if you think it's relatively minor,
     it's helpful to know what people are working on.  Mention in the initial
     issue that you are planning to work on that bug or feature so that it can
     be assigned to you.

  1. Follow the normal process of [forking][] the project, and setup a new
     branch to work in.  It's important that each group of changes be done in
     separate branches in order to ensure that a pull request only includes the
     commits related to that bug or feature.

  1. Go makes it very simple to ensure properly formatted code, so always run
     `go fmt` on your code before committing it.  You should also run
     [golint][] over your code.  As noted in the [golint readme][], it's not
     strictly necessary that your code be completely "lint-free", but this will
     help you find common style issues.

  1. Any significant changes should almost always be accompanied by tests.  The
     project already has good test coverage, so look at some of the existing
     tests if you're unsure how to go about it.  [gocov][] and [gocov-html][]
     are invaluable tools for seeing which parts of your code aren't being
     exercised by your tests.

  1. Do your best to have [well-formed commit messages][] for each change.
     This provides consistency throughout the project, and ensures that commit
     messages are able to be formatted properly by various git tools.

  1. Finally, push the commits to your fork and submit a [pull request][].

[forking]: https://help.github.com/articles/fork-a-repo
[golint]: https://github.com/golang/lint
[golint readme]: https://github.com/golang/lint/blob/master/README
[gocov]: https://github.com/axw/gocov
[gocov-html]: https://github.com/matm/gocov-html
[well-formed commit messages]: http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html
[squash]: http://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits
[pull request]: https://help.github.com/articles/creating-a-pull-request


## Other notes on code organization ##

Currently, everything is defined in the main `github` package, with API methods
broken into separate service objects.  These services map directly to how
the [GitHub API documentation][] is organized, so use that as your guide for
where to put new methods.

Code is organized in files also based pretty closely on the GitHub API
documentation, following the format `{service}_{api}.go`.  For example, methods
defined at <https://developer.github.com/v3/repos/hooks/> live in
[repos_hooks.go][].

[GitHub API documentation]: http://developer.github.com/v3/
[repos_hooks.go]: https://github.com/google/go-github/blob/master/github/repos_hooks.go


## Maintainer's Guide ##

(These notes are mostly only for people merging in pull requests.)

**First and foremost, try to maintain a clean, linear git history.**  With very
few exceptions, running `git log` should not show a bunch of branching and
merging.

Never use the GitHub "merge" button, since it always creates a merge commit.
Instead, check out the pull request locally ([these git aliases
help][git-aliases]), then cherry-pick or rebase them onto master.  If there are
small cleanup commits, especially as a result of addressing code review
comments, these should almost always be squashed down to a single commit.  Don't
bother squashing commits that really deserve to be separate though.  If needed,
feel free to amend additional small changes to the code or commit message that
aren't worth going through code review for.

If you made any changes like squashing commits, rebasing onto master, etc, then
GitHub won't recognize that this is the same commit in order to mark the pull
request as "merged".  So instead, amend the commit message to include a line
"Fixes #0", referencing the pull request number.  This would be in addition to
any other "Fixes" lines for closing related issues.  If you forget to do this,
you can also leave a comment on the pull request [like this][rebase-comment].
If you made any other changes, it's worth noting that as well, [like
this][modified-comment].

If this is the first pull request from a new contributor, make sure they've
signed a CLA and then add them to the AUTHORS and CONTRIBUTORS file.  If they
are contributing on behalf of a company, the individual goes in CONTRIBUTORS and
the company goes in AUTHORS.  Contributors should never add themselves to these
files.  If they try to, don't merge that commit.  These files should only ever
be modified by project maintainers so that the git history of these files
identifies who actually did the CLA verification.

[git-aliases]: https://github.com/willnorris/dotfiles/blob/d640d010c23b1116bdb3d4dc12088ed26120d87d/git/.gitconfig#L13-L15
[rebase-comment]: https://github.com/google/go-github/pull/277#issuecomment-183035491
[modified-comment]: https://github.com/google/go-github/pull/280#issuecomment-184859046
