rails/rails — pull request #18125 by codeodor (2014-12-21 16:21:01+00:00)
Title: Clarify ActiveRecord testing guidelines [ci skip]

1. Specify that you need to create the test databases, and that no special
Rails command needs to be run to do that.
2. Although the underscore style of `rake test_mysql` works, make the
documentation of running the tests in RUNNING_UNIT_TESTS.rdoc
consistent with the "Contributing..." guide.
3. Promote "Testing Active Record" to not be a subsection of
"Running a Single Test," since it doesn't make sense as a subsection
of that.