Running only failing tests with RSpec

A common pattern in TDD is to make changes, run the suite, fix any failing tests and finally run the suite again to ensure everything is green.

A newt way to speed up this flow is by using the --only-failures flag with RSpec which only runs the recent failing tests.

For this to work you need to add the following to your spec_helper.rb:

RSpec.configure do |c|
  c.example_status_persistence_file_path = "tmp/examples.txt"
end

Now you can run the recent failures via rspec --only-failures.

You can even pick them off one at a time with rspec --next-failure.