This is unofficial documentation for GitHub Actions in general, based on the experience of developing this R package. GitHub Actions is still in limited beta, and the features described here may change quickly. Here is the official documentation.
Testing is always a good idea for software development, but it’s especially important for workflow automation and continuous integration and delivery. These scripts may be relatively simple, but any bugs they may have are doubly thorny: If something goes wrong, you can’t be sure whether the workflow script or your in-development software are at fault and it can be quite hard to find out what is going on.
That is why the tools running continuous integration and delivery (CI/CD) especially, should be thoroughly tested.