Thanks for the great library, we use Mocha extensibly on our test and love its readability and no-nonsense-ness. One thing that would be great, but that seems to be against some of the testing philosophy (which we don''t quite deeply understand yet, so we can''t come up with kosher alternatives) is the ability to be more flexible with the return values. Presently the only flexibility is to pass a Proc, but even this is going away. Ideally you could be as flexible as passing a block that received the call''s parameters (which the Proc presently doesn''t receive) so arbitrary logic could be used. Knowing that the more specific tests are the better, this flexibility allows for tests to be less brittle. More concretely, in our case we are using Mocha to mock and stub calls to a remote server. The code under test batches the calls for efficiency so that the exact request parameters are not known on each invokation, and the particular test wants to be independent of the batching parameters. Other cases might be that the number of possible return values is large given the inputs and can be expressed more succintly as a simple formula on the paramteters. Or the input and output must be ordered data but the order is not known or arbitrarily set by an intermediate component (e.g. a database). Or is there some other way that we are missing? thanks for elucidating us and for the great work on this library. Jaime Cham