# Contributing to Uncrustify

## How to contribute

There are lots of ways to contribute to Uncrustify:

- Report Issues

- Propose Features or Improvements

- Submit Pull Requests

## Making changes

* Pull latest [master][master] and create a new branch:
    - Branch name _should_ use lowercase, using `-` to separate words
      and not `_`. Other special characters _should_ be avoided.
      (However, feel free to use option names verbatim in branch names;
      `_` _should_ be used when part of an option name.)
    - A hierarchical structure _may_ be designated using `/`
      (e.g. `area/topic`), although this is uncommon.
      The last part of the name can be keywords like `bugfix`, `feature`,
      `optim`, `docs`, `refactor`, `test`, etc.
    - Branches _should_ be named after _what_ the change is about.
    - Branches _should not_ be named after the issue number,
      developer name, etc.

* Organize your work:
    - Specialize your branch to target only one thing.
      Split your work in multiple branches if necessary.
    - Make commits of logical units.
    - Avoid "fix-up" commits.
      Instead, rewrite your history so that the original commit is "clean".
    - Try to write a [quality commit message][commits]:
        + Separate subject line from body with a blank line.
        + Limit subject line to 50 characters.
        + Capitalize the subject line.
        + Do not end the subject line with a period.
        + Use imperative present tense in the subject line.
          A proper subject can complete the sentence
          "If applied, this commit will, [subject]".
        + Wrap the body at 72 characters.
        + Include motivation for the change
          and contrast its implementation with previous behavior.
          Explain the _what_ and _why_ instead of _how_.
    - If the git diff command, or the diff part of the git gui,
      don't produce accurate output, it might be necessary to add
      some lines to the ~/.gitconfig file:
         [diff]
                 algorithm = patience
         [gui]
                 diffopts = --patience


* Add or update unit tests:
    - All behavioral changes should come with a unit test that verifies
      that the new feature or fixed issue works as expected.
    - Consider improving existing tests if it makes sense to do so.
    - Any unused test number may be used,
      however it is preferred to keep related tests together, if possible.
    - Read [Writing Tests][tests] for more details.

* Polish your work:
    - The code should be clean, with documentation where needed.
    - The change must be complete (no upcoming fix-up commits).
    - Functional changes should always be accompanied by tests (see above).
      Changes without tests should explain why tests are not present.
      (Changes that are non-functional, such as documentation changes,
      can usually omit tests without justification.)

* Prepare a Pull Request (PR):
    - To reduce the likelihood of conflicts and test failures,
      consider rebasing your work on top of latest master before creating a PR.
    - Verify that your code is working properly
      by running `ctest` in your build directory.
      (Changes that fail CI will _not_ be merged.
      Running the tests locally will help to avoid this.)
      You can change the level of logging by changing the line 104 and 109
      of the file tests/test_uncrustify/test.py to another value.
    - The PR title should represent _what_ is being changed
      (a rephrasing of the branch name if set correctly).
    - The PR description should document the _why_ the change needed to be done
      and not _how_, which should be obvious by doing the code review.

[master]: https://github.com/uncrustify/uncrustify/tree/master
[commits]: https://chris.beams.io/posts/git-commit/
[tests]: https://github.com/uncrustify/uncrustify/wiki/Writing-Tests
