When making unit tests for objective C, how do you test blocks?

Question

I have a function (internally uses ASIHTTPRequest) which calls a block with the result:

[Http get:@"http://api.geonames.org/postalCodeLookupJSON"
   params:params cacheMins:0 complete:^(NSDictionary *response, BOOL success) {
       STAssertTrue(success, @"JSON retrieved OK");
       STFail(@"blah");
}];

I want to test the above, but it seems the test doesn't get called.

How can i ensure that the test waits till the block is called?

-edit-

Of course i don't recommend to do this in the main app in the gui thread, in this particular situation it is only for a unit test.

Answer 1

Found a solution:

Wait for code to finish execution

Eg:

__block int done=0;
[Http get:@"http://api.geonames.org/postalCodeLookupJSON"
   params:params cacheMins:0 complete:^(NSDictionary *response, BOOL success) {
       STAssertTrue(success, @"JSON retrieved OK");
       NSArray *postalcodes = [response objectForKey:@"postalcodes"];
       NSDictionary *first = [postalcodes objectAtIndex:0];
       NSString *adminName1 = [first objectForKey:@"adminName1"];
       STAssertTrue([adminName1 isEqualToString:@"New South Wales"], @"NSW");
       done=1;
}];

// https://stackoverflow.com/questions/3615939/wait-for-code-to-finish-execution
while (!done) {
    // This executes another run loop.
    [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
    // Sleep 1/100th sec
    usleep(10000);
}

Answer 2

Not sure where I found this, but there's a better way that doesn't use sleeps:

while (CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0, true) && !placeMarkUpdated){};

here it is in context, testing a reverse geocoding request:

__block BOOL placeMarkUpdated = NO;

[geocoder reverseGeocodeLocation:location completionHandler:^(NSArray *placemarks, NSError *error) {
    if (placeMarkUpdated == NO) {
        placeMarkUpdated = YES;
        CLPlacemark *placemark = [placemarks objectAtIndex:0];
        address = [Address addressFromPlacemark:placemark];
    }
}];

while (CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0, true) && !placeMarkUpdated){};

Sleeps suck cause they slow down the build (I know 5s doesn't sound bad, but consider the old story: guy goes to doctor cause his knees hurt from running, Doctor says 'get up on the table' and taps his knee and says 'does that hurt?' guy says 'no,' doctor: 'it would if I did it 10K times...'