ruby/doc/contributing/making_changes_to_ruby.md

Contributing a pull request

Code style

Here are some general rules to follow when writing Ruby and C code for CRuby:

• Do not change code unrelated to your pull request (including style fixes)
• Indent 4 spaces for C without tabs (tabs are two levels of indentation, equivalent to 8 spaces)
• Indent 2 spaces for Ruby without tabs
• ANSI C style for function declarations
• Follow C99 Standard
• PascalStyle for class/module names
• UNDERSCORE_SEPARATED_UPPER_CASE for other constants
• Abbreviations should be all upper case

Commit messages

Use the following style for commit messages:

• Use a succinct subject line
• Include reasoning behind the change in the commit message, focusing on why the change is being made
• Refer to issue (such as Fixes [Bug #1234] or Implements [Feature #3456]), or discussion on the mailing list (such as [ruby-core:12345])

CI

GitHub actions will run on each pull request.

There is a CI that runs on master. It has broad coverage of different systems and architectures, such as Solaris SPARC and macOS.