Re: [RFC PATCH 0/2] add an external testing library for unit tests

> In our current testing environment, we spend a significant amount of
> effort crafting end-to-end tests for error conditions that could easily
> be captured by unit tests (or we simply forgo some hard-to-setup and
> rare error conditions). Unit tests additionally provide stability to the
> codebase and can simplify debugging through isolation. Turning parts of
> Git into libraries[1] gives us the ability to run unit tests on the
> libraries and to write unit tests in C. Writing unit tests in pure C,
> rather than with our current shell/test-tool helper setup, simplifies
> test setup, simplifies passing data around (no shell-isms required), and
> reduces testing runtime by not spawning a separate process for every
> test invocation.