For us to be able to accept code contributions, they have to build and pass tests. For portions of the code that don't have a working build and working tests, we will not be able to accept contributions.
As of March 2021, we have some unit test coverage and a CMake-based working build.
If you are interested in contributing code, we would like to hear from you! You can create a new issue (explaining the idea, feature, or improvement) or comment on an existing issue and state your interest in working on it here on GitHub.
Before we can review and accept a pull request from you, you'll need to sign a Contributor License Agreement (CLA). The CLA ensures that the community is free to use your contributions. More information about the agreement is available on the Microsoft web site. Signing the CLA is an automated process, and you only need to do it once for Microsoft projects on GitHub.
You don't need to sign a CLA until you're ready to create a pull request. When your pull request is created, it is classified by a bot. If the change is trivial (i.e. you just fixed a typo) then the bot will label the PR cla-not-required. Otherwise, it's classified as cla-required. In that case, the system will also tell you how you can sign the CLA. Once you have signed a CLA, the current and all future pull requests will be labeled as cla-signed.