Mocking is a great part of RSpec, and from the documentation it looks insanely easy. What had me frustrated on a current project is the fact that the mocks and stubs wouldn’t always do what I’d expect them to do. No errors when methods weren’t invoked, and, the worst part, mocks wouldn’t be cleaned up between examples which resulted in rather weird errors. They only occurred when run as a whole with rake spec but not when I ran the specs through TextMate.

I was going insane, because noone on the mailing list seemed to have any problems, same for friends working with RSpec. Then I had another look at the RSpec configuration.

Turns out, the reason for all of this is that Mocha was used for mocking. Switching the configuration back to use RSpec’s internal mocking implementation, everything worked like a charme from then on.

So what you want to have in your SpecHelper isn’t this:

Spec::Runner.configure do |config|
  config.mock_with :mocha
end

but rather

Spec::Runner.configure do |config|
  config.mock_with :rspec
end

or no mention at all of mock_with which will result in the default implementation being used which is, you guessed it, RSpec’s own.