Question

I have a method that takes a response block and an error block, I write unit test by giving it valid data and invalid data so it will call response block and error block respectively, but with GHUnit and OCMock, how do I test if the correct block is called?

I was thinking:

for valid data:
response
{
GHAssertTrue(YES, @””);
}
error
{
GHAssertTrue(NO, @”Valid data should not call error block”);
}

and vice-versa for invalid data.

Is what I did correct?

Answer 1

The problem with putting your assertions in the blocks is that you wouldn’t know if neither block were called. This is what we do:

__block BOOL done = NO;
[classUnderTest doSomethingWithResultBlock:^(BOOL success) {
    done = YES;
} errorBlock:^(BOOL success) {
    // should not be called
    expect(NO).to.beTruthy();
}];
while (!done) [[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.01]];

The drawback is that if the success block is never called, the tests will hang in the while loop. You could avoid that by adding a timeout:

NSDate *startTime = [NSDate date];
__block BOOL done = NO;
[classUnderTest doSomethingWithResultBlock:^(BOOL success) {
    done = YES;
} errorBlock:^(BOOL success) {
    // should not be called
    expect(NO).to.beTruthy();
}];
while (!done && [startTime timeIntervalSinceNow] > -30) [[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.01]];
// make sure it didn't time out
expect(done).to.beTruthy();