ProgressReporter is designed for interactive use. Its goal is to give you actionable insights to help you understand the status of your code. This reporter also praises you from time-to-time if all your tests pass. It's the default reporter for test_dir().

ParallelProgressReporter is very similar to ProgressReporter, but works better for packages that want parallel tests.

CompactProgressReporter is a minimal version of ProgressReporter designed for use with single files. It's the default reporter for test_file().