Yes, there is. Conceptually anyway.

The oft-cited [article by Martin Fowler](http://martinfowler.com/articles/mocksArentStubs.html) is pretty dense, so here is a reasonable [stack overflow thread](http://stackoverflow.com/questions/3459287/whats-the-difference-between-a-mock-stub).

Basically, use a mock if you are expecting a method to be called, and use a stub if you need to set a fake return value.

If you follow command/query separation, the difference is obvious. You *stub* queries, and you *mock* command expectations.

**However**, in rspec there is no functional difference (in some other test-double frameworks there is). I just try to use the correct term for clarity.

In this case, I changed it to a stub because there are no method expectations set; it doesn't matter that the `BreadcrumbsHelper` calls `belong_to_config`, it just matters what the call returns when it is called.

I hope this makes sense, and I'm sorry for making unrelated changes, I just have a habit of trying to clarify code that I go through...