Lambda matcher and more validation methods

[liron-l]

Lambda matcher allows comparing complex expressions compare instead of
eq or any
-- AtMost and AtLeast call validator (take a look at the following
variety in the moq library)
http://www.nudoq.org/#!/Packages/Moq/Moq/Times

Signed-off-by: Liron Levin [email protected]

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[liron-l]

I signed it!

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CLAs look good, thanks!

[dsymonds]

Thanks, but we don't need every possible matcher implementation to be in this repo. They can be elsewhere.

[liron-l]

Thanks @dsymonds, what do you mean by elsewhere, as a consumer, I would expect a mocking framework to include as much API and utilities as possible.
Also, comparing using lambda (as opposed to property equality, All or nil) is much more common in practice (at least from my experience).
See for example:
It.Is -Moq (very popular framework for c#) - https://github.com/Moq/moq4/blob/8bc9b111640203af3995fbac98160a5d1f9e1ae2/Source/It.cs
Is.Matching (Rhino Mocks) ->
http://ayende.com/wiki/Rhino+Mocks+Constraints.ashx
We can replace lambda with Match or a less confusing term if you think it's more appropriate.

Also, adding validator such as at least, at most and between is very helpful in testing.

[dsymonds]

Gomock does not aspire to be all-inclusive of every possible matcher and utility. They work just as well if they live elsewhere.