bbatsov/rubocop — pull request #1182 by jonas054 (2014-06-28 13:53:22+00:00)
Title: [Fix #1157] Validate --only arguments later

Whether cop names given to `--only` are valid or not can not be determined until configuration has been loaded. So we can't do validation during option parsing.

Testing proved difficult and this solution adds a spec example that takes just over 1 second to run on my machine.