Projects For LibGit2

So, you want to start helping out with libgit2? That's fantastic! We welcome contributions and we promise we'll try to be nice.

This is a list of libgit2 related projects that new contributors can take on. It includes a number of good starter projects as well as some larger ideas that no one is actively working on.

Before You Start

Please start by reading the README.md, CONTRIBUTING.md, and CONVENTIONS.md files before diving into one of these projects. Those explain our work flow and coding conventions to help ensure that your work will be easily integrated into libgit2.

Next, work through the build instructions and make sure you can clone the repository, compile it, and run the tests successfully. That will make sure that your development environment is set up correctly and you are ready to start on libgit2 development.

Starter Projects

These are good small projects to get started with libgit2.

• Look at the examples/ programs, find an existing one that mirrors a core Git command and add a missing command-line option. There are many gaps right now and this helps demonstrate how to use the library. Here are some specific ideas (though there are many more):
  • Fix the examples/diff.c implementation of the -B (a.k.a. --break-rewrites) command line option to actually look for the optional [<n>][/<m>] configuration values. There is an existing comment that reads /* TODO: parse thresholds */. The trick to this one will be doing it in a manner that is clean and simple, but still handles the various cases correctly (e.g. -B/70% is apparently a legal setting).
  • Implement the --log-size option for examples/log.c. I think all the data is available, you would just need to add the code into the print_commit() routine (along with a way of passing the option into that function).
  • As an extension to the matching idea for examples/log.c, add the -i option to use strcasestr() for matches.
  • For examples/log.c, implement the --first-parent option now that libgit2 supports it in the revwalk API.
• Pick a Git command that is not already emulated in examples/ and write a new example that mirrors the behavior. Examples don't have to be perfect emulations, but should demonstrate how to use the libgit2 APIs to get results that are similar to Git commands. This lets you (and us) easily exercise a particular facet of the API and measure compatibility and feature parity with core git.
• Submit a PR to clarify documentation! While we do try to document all of the APIs, your fresh eyes on the documentation will find areas that are confusing much more easily.

If none of these appeal to you, take a look at our issues list to see if there are any unresolved issues you'd like to jump in on.

Larger Projects

These are ideas for larger projects mostly taken from our backlog of Issues. Please don't dive into one of these as a first project for libgit2 - we'd rather get to know you first by successfully shipping your work on one of the smaller projects above.

Some of these projects are broken down into subprojects and/or have some incremental steps listed towards the larger goal. Those steps might make good smaller projects by themselves.

• Port part of the Git test suite to run against the command line emulation in examples/
  • Pick a Git command that is emulated in our examples/ area
  • Extract the Git tests that exercise that command
  • Convert the tests to call our emulation
  • These tests could go in examples/tests/...
• Add hooks API to enumerate and manage hooks (not run them at this point)
  • Enumeration of available hooks
  • Lookup API to see which hooks have a script and get the script
  • Read/write API to load a hook script and write a hook script
  • Eventually, callback API to invoke a hook callback when libgit2 executes the action in question
• Isolate logic of ignore evaluation into a standalone API
• Upgrade internal libxdiff code to latest from core Git
• Tree builder improvements:
  • Extend to allow building a tree hierarchy
• Apply-patch API
• Add a patch editing API to enable "git add -p" type operations
• Textconv API to filter binary data before generating diffs (something like the current Filter API, probably).
• Performance profiling and improvement
• Support "git replace" ref replacements
• Include conflicts in diff results and in status
  • GIT_DELTA_CONFLICT for items in conflict (with multiple files)
  • Appropriate flags for status
• Support sparse checkout (i.e. "core.sparsecheckout" and ".git/info/sparse-checkout")