Adding in to your point, it's really easy to get familiar with a codebase and be confident that there are no regressions when you make changes if there are comp

Adding in to your point, it's really easy to get familiar with a codebase and be confident that there are no regressions when you make changes if there are comprehensive tests. Similarly, tests can serve as a device for asserting contributions are acceptable pre/post-merge as well as evaluating that your dependencies work as expected.