Support multiple capture invocations

[marchaos]

Hey,
I'm pretty sure this currently isn't supported, but it would be nice to allow for captures to capture multiple calls to the same method. See this example of mockito:

http://stackoverflow.com/questions/5981605/can-mockito-capture-arguments-of-a-method-called-multiple-times

I guess the API would need something similar where you can call capture.getAllValues()

[marchaos]

Please see https://github.com/marchaos/testdouble.js/blob/master/src/matchers/captor.coffee. This works for me. If there is only one invocation, the captor.value contains the captured value, otherwise captor.value is an array of all calls in the order the occurred. This allows for some backwards compatibility.

[searls]

I'm struggling to imagine very many examples where this would be needed. Can you think of a not-far-fetched example?

[marchaos]

It's a common pattern in streaming applications. I have a callback that is called whenever a message is received from a streaming source.

In my usecase, I mock multiple messages of different types to ensure the underlying code handles those accordingly. This needs to be occur in 1 unit test as messages come in on batch. In my captor, I catch each processed message and assert that they contain the correct values.

[searls]

Okay. I think I can get behind adding a values attribute that shows all captured invocations and leave value as whatever the most-recent one was. That seems reasonable to me, since it wouldn't break back-compat. Do you agree?

[marchaos]

Hi Justin, yep that sounds like a plan. Do you want me to create a PR for this?

[searls]

Yeah, please feel free

[marchaos]

#144

[searls]

This landed in testdouble@1.8.0 for anyone keeping score.