############################
Contributing to edx-platform
############################

Contributions to edx-platform are very welcome, and strongly encouraged! The
easiest way is to fork the repo and then make a pull request from your fork.
Read on for details on how to become a contributor, edx-platform code quality,
testing, making a pull request, and more.


Becoming a Contributor
======================

Before your first pull request is merged, you'll need to sign the `individual
contributor agreement`_ and send it in. This confirms you have the authority to
contribute the code in the pull request and ensures we can relicense it.

You should print out the agreement and sign it. Then scan (or photograph) the
signed agreement and email it to the email address indicated on the agreement.
Alternatively, you're also free to physically mail the agreement to the street
address on the agreement. Once we have your agreement in hand, we can begin
merging your work.

You'll also need to add yourself to the `AUTHORS` file when you submit your
first pull request.  You should add your full name as well as the email address
associated with your Github account.  Please update `AUTHORS` in an individual
commit, distinct from other changes in the pull request (it's OK for a pull
request to contain multiple commits, including a commit to `AUTHORS`).
Alternatively, you can open up a separate PR just to have your name added to
the `AUTHORS` file, and link that PR to the PR with your changes.


Code Quality Guidelines
=======================

Comments
--------

We expect you to contribute code that is self-documenting as much as possible.
This means submitting code with well-formed variable, function, class, and
method names; good docstrings; lots of comments. Use your discretion - not
every line needs to be commented. However, code that is obtuse is hard to
maintain and hard for others to build upon. So please do your best to provide
code that is easy to read and well-commented.

Python/Javascript Styling
-------------------------

Before you submit your first pull request, please review the edx-platform code
quality and style guidelines:

* `Python Guidelines <https://github.com/edx/edx-platform/wiki/Python-Guidelines>`_
* `Javascript Guidelines <https://github.com/edx/edx-platform/wiki/Javascript-Guidelines>`_

Coding conventions should be followed. Your submission should not introduce any
new pep8 or pylint errors (and ideally, should fix up other errors you
encounter in the files you edit). From the edx-platform main directory, you can
run the command::

    $ rake quality

to print the "Diff Quality" report, a report of the quality violations your
branch has made.

Although we try to be vigilant and resolve all quality violations, some Pylint
violations are just too challenging to resolve, so we opt to ignore them via
use of a pragma. A pragma tells Pylint to ignore the violation in the given
line. An example is::

    self.assertEquals(msg, form._errors['course_id'][0])  # pylint: disable=protected-access

The pragma starts with a ``#`` two spaces after the end of the line. We prefer
that you use the full name of the error (``pylint: disable=unused-argument`` as
opposed to ``pylint: disable=W0613``), so it's more clear what you're disabling
in the line.

If you have any questions, don't hesitate to reach out to us on email or IRC;
see the section on **Contacting Us**, below, for more.


Testing Coverage Guidelines
===========================

Before you submit a pull request, please refer to the `edx-platform testing
documentation`_.

Code you commit should *increase* test coverage, not decrease it. For more
involved contributions, you may want to discuss your intentions on the mailing
list *before* you start coding.

Running the command ::

    $ rake test

in the edx-platform directory will run all the unit tests on edx-platform (to
run specific tests, refer to the testing documentation). Once you've run this
command, you can run ::

    $ rake coverage

to generate the "Diff Coverage" report. This report tells you how much of the
Python and JavaScript code you've changed is covered by unit tests. We aim for
a coverage report score of 95% or higher. We also encourage you to write
acceptance tests as your changes require. For more in-depth help on various
types of tests, please refer to the `edx-platform testing documentation`_.


Opening A Pull Request
======================

When you open a pull request (PR), please follow these guidelines:

* In the PR description, please be as clear as possible explaining what the
  change is. This helps us so much in contextualizing your PR and providing
  appropriate reviewers for you. Take a look at `pull request 1322`_ for an
  example of a verbose PR description for a new feature.

* As far as code goes, a first pass is to make sure that your code is of high
  quality. This means ensuring plenty of comments, as well as a 100% pass rate
  when you run ``rake quality`` locally. See the section **Code Quality
  Guidelines**.

* Testing coverage should be as complete as possible. 95% or greater on
  JavaScript and Python coverage (you can check this by running ``rake test;
  rake coverage`` locally). Percentage coverage is only calculated from unit
  tests, however. If you're adding new visual features, we love seeing
  acceptance tests as applicable. See the section **Testing Coverage
  Guidelines**.

* Be sure that your commit history is *clean* - that is, you don't have a ton
  of tiny commits with throwaway commit messages such as "Fix", "Arugh",
  "asdfjkl;", "Merge branch Master into fork", etc. Commit messages should be
  concise and explain what work was done. The first line should be fewer than
  50 characters; you may add additional lines to your commit messages for
  further explaination.

  * To clean up your commit history you'll need to perform an *interactive
    rebase* where you squash your commits together. More about interactive
    rebase can be found in the `github help documents`_ or by Googling.

  * The reasoning behind a clean commit history is that we want the log of all
    commits in edx-platform to be readable and self-documenting. This way,
    developers can take a look at all recent commits in the past few days or
    weeks and have a good understanding of all the code changes that were made.

* The `CHANGELOG` is a list of changes to the platform, distinct from the git
  log because the audience is not developers but rather users of our platform
  (specifically, course authors). Please make an entry in `CHANGELOG`
  describing your change if it is something that you think platform users would
  be interested in - eg a major bugfix, new feature, or update to existing
  functionality. Be sure to also indicate what system (LMS, CMS, etc) your
  change affects. If in doubt if your change is "big enough", we encourage you
  to make a `CHANGELOG` entry!

* Make sure that your branch is freshly rebased on master when you go to open
  your pull request. If you don't have repo permissions, you won't be able to
  see if your branch is able to be cleanly merged or not. We'll tell you if
  it's not; however, rebasing before you open your PR will help decrease the
  frequency of conflicts.

* If you need help with rebasing, please see the following resources:

  1. `Git Book <http://git-scm.com/book/en/Git-Branching-Rebasing>`_
  2. `Git Docs <http://git-scm.com/docs/git-rebase>`_
  3. `Interactive Git tutorial <http://pcottle.github.io/learnGitBranching/>`_ -- totally awesome!!
  4. `Git Ready <http://gitready.com/intermediate/2009/01/31/intro-to-rebase.html>`_


Finally, **Please Do Not** close a pull request and open a new one to respond
to review comments. Keep the same pull request open, so it's clear how your
code has been worked upon and what reviewers have been involved in the
conversation. Rebase as needed to get updated code from master into your
branch.


Expectations We Have of You
---------------------------

By opening up a pull request, we expect the following things:

1. You've read and understand the instructions in this contributing file.

2. You are ready to engage with the edX community. Engaging means you will be
   prompt in following up with review comments and critiques. Do not open up a
   pull request right before a vacation or heavy workload that will render you
   unable to participate in the review process.

3. If you have questions, you will ask them by either commenting on the pull
   request or asking us in IRC or on the mailing list. 

4. If you do not respond to comments on your pull request within 7 days, we
   will close it. You are welcome to re-open it when you are ready to engage.


Expections You Have of Us
-------------------------

1. Within a week of opening up a pull request, one of our open source community
   managers will triage it, either tagging other reviewers for the PR or asking
   follow up questions (Please give us a little extra time if you open the PR
   on a weekend or around a US holiday! We may take a little longer getting to
   it.).

2. We promise to engage in an active dialogue with you from the time we begin
   reviewing until either the PR is merged (by an edX staff member), or we
   decide that, for whatever reason, it should be closed.

3. Once we have determined through visual review that your code is not
   malicious, we will run a Jenkins build on your branch.


Using Jenkins Builds
--------------------

When you open up a pull request, an edX staff member can decide to run a
Jenkins build on your branch. We will do this once we have determined that your
code is not malicious.

When a Jenkins job is run, all unit, Javascript, and acceptance tests are run.

**If the build fails...**

Click on the build to be brought to the build page. You'll see a matrix of blue
and red dots; the red dots indicate what section failing tests were present in.
You can click on the test name to be brought to an error trace that explains
why the tests fail. Please address the failing tests before requesting a new
build on your branch. If the failures appear to not have anything to do with
your code, it may be the case that the master branch is failing. You can ask
your reviewers for advice in this scenario.

If the build says "Unstable" but passes all tests, you have introduced too many
pep8 and pylint violations. Please refer to the **Code Quality Guidelines**
section and clean up the code.

**If the build passes...**

If all the tests pass, the "Diff Coverage" and "Diff Quality" reports are
generated. Click on the "View Reports" link on your pull request to be brought
to the Jenkins report page. In a column on the left side of the page are a few
links, including "Diff Coverage Report" and "Diff Quality Report". View each of
these reports (making note that the Diff Quality report has two tabs - one for
pep8, and one for Pylint). 

Make sure your quality coverage is 100% and your test coverage is at least 95%.
Adjust your code appropriately if these metrics are not high enough. Be sure to
ask your reviewers for advice if you need it.


Contacting Us
=============

Mailing list
------------

If you have any questions, please ask on the `mailing list`_. It's always a
good idea to first search through the archives, to see if any of your questions
have already been asked and answered.

The edx platform team is based in the US, so we're best able to respond to
questions posted in English. You're most likely to get an answer if you ask
questions related to edx-platform code or conventions. Questions only
tangentially related to edx-platform may be better answered on different forums
or mailing lists (for example, asking for help on how to set up Git is better
posted on a Git related message list or forum).

Questions about translations, creating courses, or using Studio are not
appropriate for the edx-code mailing list. We have a few other mailing lists
you may be interested in:

* `openedx-translation <https://groups.google.com/forum/#!forum/openedx-translation>`_
* `openedx-studio <https://groups.google.com/forum/#!forum/openedx-studio>`_


IRC
---

Many edX employees and community members hang out in the #edx-code `IRC
channel`_ on Freenode.  We're always happy to see more people hanging out with
us there!

**Tips on Using IRC**

For clients, the `webchat <webchat.freenode.net>`_ is easiest, because you
don't need to install anything and it's cross-platform.  `ChatZilla
<http://chatzilla.hacksrus.com/>`_ is almost as easy -- it's a Firefox
extension, and works anywhere Firefox does. For an installed application,
`Pidgin <http://pidgin.im>`_ works decently (or `Adium <https://adium.im>`_ on
Mac), and has a familiar instant-messenger-style interface. For something truly
dedicated to IRC, there's `mIRC <http://www.mirc.com>`_ for Windows (free),
`LimeChat <http://limechat.net/mac/>`_ for Mac (free), or `Textual
<http://www.codeux.com/textual/>`_ for Mac (paid). There are also many other
clients out there, but those are some good recommendations for people
relatively new to IRC.


Pull requests/issues
--------------------

We do not make much use of Github issues, so opening an issue on edx-platform
is not the best way to reach us. However, when you've opened up a pull request,
please please don't be shy about adding comments and having a robust
conversation with your pull request reviewers.

Your pull request is a good place to ask pointed questions about the code
you've written, and we're very happy to have interaction with you through code,
commits, and comments.


.. _individual contributor agreement: http://code.edx.org/individual-contributor-agreement.pdf
.. _edx-platform testing documentation: https://github.com/edx/edx-platform/blob/master/docs/internal/testing.md
.. _mailing list: https://groups.google.com/forum/#!forum/edx-code
.. _IRC channel: http://www.irchelp.org/irchelp/new2irc.html
.. _pull request 1322: https://github.com/edx/edx-platform/pull/1322
.. _github help documents: https://help.github.com/articles/interactive-rebase
