clap/CONTRIBUTING.md

How to Contribute

Contributions are always welcome! Please use the following guidelines when contributing to clap

1. Fork clap
2. Clone your fork (git clone https://github.com/$YOUR_USERNAME/clap-rs && cd clap-rs)
3. Create new branch (git checkout -b new-branch)
4. Make your changes, and commit (git commit -am "your message")

• I use a conventional changelog format so I can update my changelog using clog
• In addition to the conventions defined above, I also use imp, wip, examples.
• Format your commit subject line using the following format: TYPE(COMPONENT): MESSAGE where TYPE is one of the following:
  • feat - A new feature
  • imp - An improvement to an existing feature
  • perf - A performance improvement
  • docs - Changes to documentation only
  • tests - Changes to the testing framework or tests only
  • fix - A bug fix
  • refactor - Code functionality doesn't change, but underlying structure may
  • style - Stylistic changes only, no functionality changes
  • wip - A work in progress commit (Should typically be git rebase'ed away)
  • chore - Catch all or things that have to do with the build system, etc
  • examples - Changes to existing example, or a new example
• The COMPONENT is optional, and may be a single file, directory, or logical component. Can be omitted if commit applies globally

5. Run the tests (cargo test --features yaml && make -C clap-tests test)
6. git rebase into concise commits and remove --fixups (git rebase -i HEAD~NUM where NUM is number of commits back)
7. Push your changes back to your fork (git push origin $your-branch)
8. Create a pull request! (You can also create the pull request first, and we'll merge when ready. This a good way to discuss proposed changes.)

Another really great way to help is if you find an interesting, or helpful way in which to use clap. You can either add it to the examples/ directory, or file an issue and tell me. I'm all about giving credit where credit is due :)

Goals

There are a few goals of clap that I'd like to maintain throughout contributions.

• Remain backwards compatible when possible
  • If backwards compatibility must be broken, use deprecation warnings if at all possible before removing legacy code
  • This does not apply for security concerns
• Parse arguments quickly
  • Parsing of arguments shouldn't slow down usage of the main program
  • This is also true of generating help and usage information (although slightly less stringent, as the program is about to exit)
• Try to be cognizant of memory usage
  • Once parsing is complete, the memory footprint of clap should be low since the main program is the star of the show
• panic! on developer error, exit gracefully on end-user error