Argument matchers for mocks.

Argument matchers for mocks.

R=paulberry@google.com, brianwilkerson@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=35415

[Paul Berry, 2014-04-24 22:13:49]

lgtm, if comment is addressed.

https://codereview.chromium.org/255503005/diff/1/pkg/analysis_server/test/typ...
File pkg/analysis_server/test/typed_mock.dart (right):

https://codereview.chromium.org/255503005/diff/1/pkg/analysis_server/test/typ...
pkg/analysis_server/test/typed_mock.dart:142: matchers.remove(matcher);
This means that the semantic effect of calling when(...) twice with the same set
of arguments is for the second behavior to override the first.  I'm not sure
that's terribly useful in situations where we are being disciplined about having
each test function test a single thing.

I prefer the convention where two calls to when(...) with the same set of
arguments means "exhibit one behavior on the first call, then exhibit the other
behavior on the second call".  That makes it easy to handle the situation where
the code under test is going to make several calls to the mock in succession.

See for example test AnalysisServerTest.addContextToWorkQueue_whenRunning, which
arranges for the first call to performAnalysisTask to return a non-empty
AnalysisResult, and the second call to return an empty one.

[scheglov, 2014-04-24 23:48:43]

https://codereview.chromium.org/255503005/diff/1/pkg/analysis_server/test/typ...
File pkg/analysis_server/test/typed_mock.dart (right):

https://codereview.chromium.org/255503005/diff/1/pkg/analysis_server/test/typ...
pkg/analysis_server/test/typed_mock.dart:142: matchers.remove(matcher);
On 2014/04/24 22:13:50, Paul Berry wrote:
> This means that the semantic effect of calling when(...) twice with the same
set
> of arguments is for the second behavior to override the first.  I'm not sure
> that's terribly useful in situations where we are being disciplined about
having
> each test function test a single thing.
> 
> I prefer the convention where two calls to when(...) with the same set of
> arguments means "exhibit one behavior on the first call, then exhibit the
other
> behavior on the second call".  That makes it easy to handle the situation
where
> the code under test is going to make several calls to the mock in succession.
> 
> See for example test AnalysisServerTest.addContextToWorkQueue_whenRunning,
which
> arranges for the first call to performAnalysisTask to return a non-empty
> AnalysisResult, and the second call to return an empty one.

As discussed offline, I'm going to reintroduce thenReturnList().
And in general second "when" with the same set of arguments is not allowed.

[scheglov, 2014-04-24 23:49:47]

Committed patchset #1 manually as r35415 (presubmit successful).

[Brian Wilkerson, 2014-04-25 15:24:36]

LGTM