#+TITLE: Contribution guidelines

Spacemacs is a volunteer effort. We encourage you to pitch in. The community
makes Spacemacs what it is. We have a few guidelines, which we ask all
contributors to follow.

You can only consider reading the sections relevant to what you are going to do:
- [[#asking-for-help][Asking for help]] if you are about to open an issue to ask a question.
- [[#reporting-issues][Reporting issues]] if you are about to open a new issue.
- [[#contributing-code][Contributing code]] if you are about to send a PR.
- [[https://github.com/syl20bnr/spacemacs/blob/develop/CONTRIBUTING.org#reviewing-pull-requests][Reviewing Pull Requests]] if you are about to review a PR.

Thanks! :heart: :heart: :heart:

* Table of Contents                     :TOC_4_gh:noexport:
- [[#asking-for-help][Asking for help]]
- [[#reporting-issues][Reporting issues]]
- [[#contributing-code][Contributing code]]
  - [[#general-contribution-guidelines][General contribution guidelines]]
    - [[#license][License]]
    - [[#conventions][Conventions]]
    - [[#changelog-entry][Changelog entry]]
    - [[#pull-request][Pull Request]]
      - [[#ideally-for-simple-prs-most-of-them][Ideally for /simple/ PRs (most of them):]]
      - [[#for-complex-prs-big-refactoring-etc][For complex PRs (big refactoring, etc):]]
    - [[#commit-messages][Commit messages]]
  - [[#contributing-a-layer][Contributing a layer]]
    - [[#file-header][File header]]
    - [[#author-of-a-new-layer][Author of a new layer]]
    - [[#contributor-to-an-existing-layer][Contributor to an existing layer]]
  - [[#contributing-a-key-binding][Contributing a key binding]]
  - [[#contributing-a-banner][Contributing a banner]]
- [[#reviewing-pull-requests][Reviewing Pull Requests]]
  - [[#using-magit-to-quickly-test-prs][Using Magit to quickly test PRs]]
- [[#additional-information][Additional information]]
  - [[#testing][Testing]]
- [[#credits][Credits]]

* Asking for help
If you want to ask an usage question, be sure to look first into some places as
it may hold the answer:
- [[https://github.com/syl20bnr/spacemacs/blob/develop/doc/FAQ.org][The FAQ]]. Some of the most frequently asked questions are answered there.
- [[https://github.com/syl20bnr/spacemacs/blob/develop/doc/DOCUMENTATION.org][The documentation]]. It’s the general documentation of Spacemacs.
- You may also read the =README.org= of the [[https://github.com/syl20bnr/spacemacs/blob/develop/doc/LAYERS.org][relevant layer(s)]].

If your question is not answered there, then please come into our [[https://gitter.im/syl20bnr/spacemacs][gitter chat]] to
discuss it with us :relaxed:. We will direct you to a solution, or ask you to
open an issue if it is needed.

* Reporting issues
Issues have to be reported on our [[https://github.com/syl20bnr/spacemacs/issues][issues tracker]]. Please:
- Check that the issue has not already been reported.
  - This can be achieved by searching keywords on the [[https://github.com/syl20bnr/spacemacs/issues][issues tracker]].
- Check that the issue has not been fixed in the =develop= version of Spacemacs.
  - This can be achieved by running Spacemacs on the =develop= branch and trying
    to reproduce the bug here. You can also check at the [[https://github.com/syl20bnr/spacemacs/tree/develop][source code]] to see if
    it has been changed/corrected.
- Try to use a clear title, and describe your problem with complete sentences.
  See also [[https://github.com/syl20bnr/spacemacs/wiki/Debugging#how-to-make-a-great-bug-report][How to make a great bug report]] in the wiki.
- Include the following information in your issue:
  - The output of =SPC h d s= (=M-m h d s= in Emacs style), which gives the
    versions information about your installation.
  - If relevant, include the mode in which the problem arise (e.g. javascript
    files, =org-mode=, etc…).
  - If possible, try to include details on how to reproduce it, like a step by
    step guide.

* Contributing code
Code contributions are welcome. Please read the following sections carefully. In
any case, feel free to join us on the [[https://gitter.im/syl20bnr/spacemacs][gitter chat]] to ask questions about
contributing!

** General contribution guidelines
*** License
The license is =GPLv3= for all parts specific to Spacemacs, this includes:
- The initialization and core files
- All the layer files.

For files not belonging to Spacemacs like local packages and libraries, refer
to the header file. Those files should not have an empty header, we may not
accept code without a proper header file.

*** Conventions
Spacemacs is based on conventions, mainly for naming functions, keybindings
definition and writing documentation. Please read the [[https://github.com/syl20bnr/spacemacs/blob/develop/doc/CONVENTIONS.org][CONVENTIONS.org]] file
before your first contribution to get to know them.

*** Changelog entry
Add a short entry describing your proposed change under a suitable subheading in
[[https://github.com/syl20bnr/spacemacs/blob/develop/CHANGELOG.develop][CHANGELOG.develop]]. Use the previous entries and [[https://github.com/syl20bnr/spacemacs/blob/develop/CONTRIBUTING.org#commit-messages][commit messages instructions]] as
guidelines. You can add your name or github username in parentheses at the end
of the entry if you want to. If an entry already exists describing your PR
(small documentation improvements etc.), you can omit the changelog entry or add
your name at the end of the pre-existing one.

*** Pull Request
Submit your contribution against the =develop= branch. You should not use
your =master= branch to modify Spacemacs, this branch is considered to be
read-only.

You may want to [[https://github.com/syl20bnr/spacemacs/wiki/Beginner%27s-Guide-to-Contributing-a-Pull-Request-to-Spacemacs][read our beginner’s guide for Pull Requests]].

/PR = Pull Request/

**** Ideally for /simple/ PRs (most of them):
- Branch from =develop=
- One topic per PR
- One commit per PR
- If you have several commits on different topics, close the PR and
  create one PR per topic
- If you still have several commits, squash them into only one commit
- Rebase your PR branch on top of upstream =develop= before submitting
  the PR

Those PRs are usually /cherry-picked/.

**** For complex PRs (big refactoring, etc):
- Squash only the commits with uninteresting changes like typos, syntax fixes,
  etc... and keep the important and /isolated/ steps in different commits.

Those PRs are /merged/ and explicitly /not fast-forwarded/.

*** Commit messages
Write commit messages according to adapted [[http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html][Tim Pope’s guidelines]]:
- Use present tense and write in the imperative: “Fix bug”, not “fixed bug” or
  “fixes bug”.
- Start with a capitalized, short (72 characters or less) summary, followed by a
  blank line.
- If necessary, add one or more paragraphs with details, wrapped at 72
  characters.
- Separate paragraphs by blank lines.

This is a model commit message:

#+BEGIN_EXAMPLE
  Capitalized, short (72 chars or less) summary

  More detailed explanatory text, if necessary.  Wrap it to about 72
  characters or so.  In some contexts, the first line is treated as the
  subject of an email and the rest of the text as the body.  The blank
  line separating the summary from the body is critical (unless you omit
  the body entirely); tools like rebase can get confused if you run the
  two together.

  Write your commit message in the imperative: "Fix bug" and not "Fixed bug"
  or "Fixes bug."  This convention matches up with commit messages generated
  by commands like git merge and git revert.

  Further paragraphs come after blank lines.

  - Bullet points are okay, too

      - Typically a hyphen or asterisk is used for the bullet, followed by a
        single space, with blank lines in between, but conventions vary here

      - Use a hanging indent
#+END_EXAMPLE

[[https://github.com/magit/magit/][Git Commit]] and [[https://github.com/magit/magit/][Magit]] provide Emacs mode for Git commit messages, which helps you
to comply to these guidelines.

** Contributing a layer
Please read the [[https://github.com/syl20bnr/spacemacs/blob/develop/doc/LAYERS.org][layers documentation]] first.

It is recommended to use the =configuration-layer/create-layer= command in order
to create a layer, as it will take care of using the files templates and will
also create the file headers correctly.

Contributed configuration layers are stored in the =layers/= folder. The
=layers/= folder also contains categories prefixed with =+= to put your layers
in. For example a layer for a language would go in the =layers/+lang/= folder.

Layer with no associated configuration will be rejected. For instance a layer
with just a package and a hook can be easily replaced by the usage of the
variable =dotspacemacs-additional-packages=.

*** File header
The file header for =elisp= files should look like the following template:

#+BEGIN_EXAMPLE
  ;;; FILENAME --- NAME Layer packages File for Spacemacs
  ;;
  ;; Copyright (c) 2012-2018 Sylvain Benner & Contributors
  ;;
  ;; Author: YOUR_NAME <YOUR_EMAIL>
  ;; URL: https://github.com/syl20bnr/spacemacs
  ;;
  ;; This file is not part of GNU Emacs.
  ;;
  ;;; License: GPLv3
#+END_EXAMPLE

You should replace =FILENAME= by the name of the file (e.g. =packages.el=)
and =NAME= by the name of the layer you are creating, don’t forget to replace
=YOUR_NAME= and =YOUR_EMAIL= also. Some files already have a template inside
=core/templates/=, so look in there first.
Note that if you use =configuration-layer/create-layer=, spacemacs will prepare
files and headers for you, and for free :smile: !

*** Author of a new layer
In the files header, change the default author name (=Sylvain Benner=) to your
name.

*** Contributor to an existing layer
If you are contributing to an already existing layer, you should not modify any
header file.

** Contributing a key binding
Key bindings are an important part of spacemacs.

First if you want to have some personal key bindings, you can freely bind them
inside the ~SPC o~ and ~SPC m o~ prefixes which are reserved for the user. This
can be done from the =dotspacemacs/user-config= function of your =.spacemacs=
file and don’t require any contribution to Spacemacs.

If you think it worth contributing a new key bindings then be sure to read
the [[https://github.com/syl20bnr/spacemacs/blob/develop/doc/CONVENTIONS.org][CONVENTIONS.org]] file to find the best key bindings, then create a
PR with your changes.

*ALWAYS* document your new key bindings or key bindings changes inside the
relevant documentation file. It should be the layer’s =README.org= file for
layer’s key bindings, or =DOCUMENTATION.org= for general Spacemacs key
bindings.

** Contributing a banner
The startup banner is by default the Spacemacs logo but there are also ASCII
banners available in the directory =core/banners/=.

If you have some ASCII skills you can submit your artwork!

You are free to choose a reasonable height size but the width size should be
around 75 characters.

* Reviewing Pull Requests
You can contribute by reviewing PRs created by others. This will help share the
workload of the project maintainers by letting them know that a PR has been
tested by an independent reviewer. The steps:
- Check that the PR complies with the guidelines in [[https://github.com/syl20bnr/spacemacs/blob/develop/CONTRIBUTING.org#contributing-code][Contributing code]].
- Check that the PR complies with [[https://github.com/syl20bnr/spacemacs/blob/develop/doc/CONVENTIONS.org][CONVENTIONS.org]].
- Check out the PR branch and test it. Remember to update your packages and your
  =~/.spacemacs= file. Testing means that you actually use the features touched
  by the PR, and the more complex or feature-rich the proposed changes are, the
  more testing is required. Be creative in trying to find bugs! Preferably, use
  the PR branch for hours or days to help stumble on unforeseen issues. Of
  course, common sense can be used and typo fixes do not need to be tested
  against bugs, but be thorough in actual code changes. Testing with a fresh
  spacemacs installation might be a good idea as well.
- Step back and think if the proposed changes could cause any other problems not
  covered by your testing. You should also ask yourself whether or not you feel
  that your testing is adequate to confidently state that this PR introduces no
  new bugs. If you feel that additional testing by more community members could
  be helpful, state so in your review.

If you find something to improve, [[https://help.github.com/articles/reviewing-proposed-changes-in-a-pull-request/][report]] it constructively and politely so the
contributor can update the PR accordingly. When you find that the PR is ready to
merge, you can leave an approving [[https://help.github.com/articles/reviewing-proposed-changes-in-a-pull-request/][review]]. Please report explicitly how you
tested the PR for bugs, and confirm that you have checked its compliance with
the code conventions. Copy the following line to your approving review to notify
the collaborators:

#+BEGIN_EXAMPLE
  Ready to be merged! (@syl20bnr @TheBB @d12frosted @bmag @JAremko)
#+END_EXAMPLE

Now the collaborators who have write access to the repository will use their
judgement to either merge the PR or require further review from another
reviewer. This is done to ensure a thorough cross-referencing in case of complex
changes, your review is very valuable in these cases as well!

** Using Magit to quickly test PRs
It is possible to manage PRs directly inside the Magit status buffer ~SPC g s~.
First add the =github= layer to your dotfile which will pull the package
=forge=. Once installed you need to set it up with a [[GitHub personal access
token][https://magit.vc/manual/ghub/Getting-Started.html#Getting-Started]] after
which you can execute ~M-x forge-pull~. It will fetch all the PRs which may take
a few seconds as we have lot of PRs. Note also that all your Magit actions will
get some additional delay due to the refresh of the PRs list.

Now, from the magit status buffer you can:
- checkout a PR with ~b y~ and searching it by name or ID
- donate all commits to develop by doing ~A d~ and selecting your current branch
  first and the develop branch second
- switch to the develop branch by pressing ~b b~ and selecting it
- delete the PR branch and remote by doing ~b x~ and selecting it

* Additional information
** Testing
Tests live in the =tests/= folder, with a folder structure corresponding to the
rest of the repository.

To run tests locally, navigate to the relevant subfolder and run =make=.

Spacemacs uses Travis CI to perform more comprehensive testing, where each
testable layer is enabled in turn.

To add tests for a layer, do the following:
1. Create a subfolder of =tests/= corresponding to the layer you want to test.
2. Write a file called =dotspacemacs.el= in that folder. It should be a minimal
   dotfile that enables the layer in question (and other layers it may depend
   on).
3. Write a number of files with tests. Please try to separate unit and
   functional tests. Look at existing tests for clues.
4. Write a =Makefile= in that folder. It should define three variables.
   - a list of additional files to load before testing (relative
     to the root Spacemacs folder). This should typically be =init.el=.
   - a list of unit test files in the current folder.
   - a list of functional test files in the current folder.

   See existing tests for examples.

   #+BEGIN_SRC makefile
     TEST_DIR := $(shell dirname $(realpath $(lastword $(MAKEFILE_LIST))))

     LOAD_FILES = ...
     UNIT_TEST_FILES = ...
     FUNC_TEST_FILES = ...

     include ../../spacemacs.mk
   #+END_SRC

5. Add the new test to list of tests in =travis/run_build.sh=.

* Credits
This =CONTRIBUTING.org= file is partially based on the [[https://github.com/rails/rails/blob/master/CONTRIBUTING.md][Rails Contribution
guidelines]] and [[https://github.com/flycheck/flycheck/blob/master/doc/contributor/contributing.rst][Flycheck Contribution guidelines]].