Sometimes when focusing on a specific area/method in a project, you may not want to run the full test suite every time you make a change. This is especially true in Rails projects, since tests can take a while to run.
Here’s how to run a single method of a test:
ruby -I test test/path/to/the_test.rb -n test_method_name
You can also run all tests in a single file with:
ruby -I test test/path/to/the_test.rb
The above works for Rails tests, since the test helper loads the Rails environment, but this is an alternative way to run tests in a single file in the context of Rails:
rake test TEST=test/path/to_file.rb
And as a general Rails testing note, if there are database issues, run
db:test:prepare before running tests, (runs all database migrations).
For Sublime Text 2 users, the RubyTest package is worth a mention. It can run a single test or all tests from within Sublime: https://github.com/maltize/sublime-text-2-ruby-tests