Contributing to rebar
Before implementing a new feature, please submit a ticket to discuss your plans.
The feature might have been rejected already, or the implementation might already be decided.
The following rules must be followed:
- Do not introduce trailing whitespace
- Do not mix spaces and tabs
- Do not introduce lines longer than 80 characters
The following rules should be followed:
- Write small functions whenever possible
- Avoid having too many clauses containing clauses containing clauses.
Basically, avoid deeply nested functions.
Pull requests and branching
Use one topic branch per pull request. If you do that, you can add extra commits or fix up
buggy commits via
git rebase -i, and update the branch. The updated branch will be
visible in the same pull request. Therefore, you should not open a new pull request when
you have to fix your changes.
Do not commit to master in your fork.
Provide a clean branch without merge commits.
As a general rule, any behavioral change to rebar requires a test to go with it. If there's
already a test case, you may have to modify that one. If there isn't a test case or a test
suite, add a new test case or suite in
inttest/. retest based tests are preferred, but
we also have EUnit tests in
Say you've added a new test case in
inttest/erlc. To only execute the modified suite,
you would do the following:
# First we build rebar and its deps to also get `deps/retest/retest` $ make debug deps # Now we can test the modified erlc suite $ deps/retest/retest -v inttest/erlc
To test EUnit tests, you would do:
$ make debug $ ./rebar -v eunit
You can also run
make test to execute both EUnit and retest tests as
make check does.
To give everyone proper credit in addition to the git history, please feel free to append
your name to
THANKS in your first contribution.
Committing your changes
Please ensure that all commits pass all tests, and do not have extra Dialyzer warnings.
To do that, run
make check. If you didn't build via
make debug at first, the beam files in
ebin/ might be missing debug_info required for xref
and Dialyzer, causing a test
If that happens, running
make clean before running
make check could solve the problem.
Structuring your commits
Fixing a bug is one commit.
Adding a feature is one commit.
Adding two features is two commits.
Two unrelated changes is two commits.
If you fix a (buggy) commit, squash (
git rebase -i) the changes as a fixup commit into
the original commit.
Writing Commit Messages
It's important to write a proper commit title and description. The commit title must be
at most 50 characters; it is the first line of the commit text. The second line of the
commit text must be left blank. The third line and beyond is the commit message. You
should write a commit message. If you do, wrap all lines at 72 characters. You should
explain what the commit does, what references you used, and any other information
that helps understanding your changes.
Basically, structure your commit message like this:
One line summary (at most 50 characters) Longer description (wrap at 72 characters)
- At most 50 characters
- What was changed
- Imperative present tense (Fix, Add, Change)
Fix bug 123
Add 'foobar' command
Change default timeout to 123
- No period
- Wrap at 72 characters
- Why, explain intention and implementation approach
- Present tense