A Shorthand For Rerunning Failed Tests With RSpec

After running a group of tests -- whether it is the entire suite or just the tests in a file -- you may find that you have a few failures. Often the goal is to focus in on these failures and get back to a green test suite. Rather than rerunning everything each time you make a change, you can instruct rspec to just rerun the tests that failed. This can be done with the --only-failures flag or --on flag for short.