How to use OCMockito to check the value inserted into UserDefault

Question

I am staring to use OCMockito for Unit Testing. Right now I am using it to mock a UserDefaults(through dependency injection).

I can control what is returned back by: [given([mockUserDefaults objectForKey:@"some key"]) willReturn:@"a value I want"];

Now my question is: How do I check what values the user set to the mock UserDefaults?

for example, if user issued: [self.userDefaults setObject:[NSDate date] forKey:"example"];

How do I get the date back from the mock userDefaults?

Answer 1

OCMockito doesn't have a way (yet) to capture and return arguments. Instead, each argument must satisfy an OCHamcrest matcher. If no matcher is specified, then equalTo is assumed.

Testing [NSDate date] is generally not a good idea in unit tests, because you have no control over the date. But for the sake of example, here's a verification that the argument is any NSDate. (sut is the "system under test".)

[verify(sut.userDefaults) setObject:instanceOf([NSDate class]) forKey:@"example"];

So here, the first matcher is instanceOf to match any NSDate.

The second matcher is implicitly equalTo(@"example)

Update:

OCMockito 1.1.0 has a way to capture arguments, using MKTArgumentCaptor:

MKTArgumentCaptor *argument = [[MKTArgumentCaptor alloc] init];
[verify(sut.userDefaults) setObject:[argument capture] forKey:@"example"];

You can retrieve the captured argument with [argument value], or an array of all captured arguments with [argument allValues].