Delay execution of Kiwi specs until an asynchronous process finishes.

example_test.m

#import <Kiwi/Kiwi.h>
#import "KWSpec+WaitFor.h"

SPEC_BEGIN(Example)

describe(@"it takes a while", ^{
    __block NSDictionary *apiResponse = nil;
    beforeAll(^{
        __block BOOL requestCompleted = NO;    
        AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request 
            success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
                requestCompleted = YES;
                apiResponse = JSON;
            } 
            failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
                requestCompleted = YES;
            }
        ];
        [operation start];

        [KWSpec waitWithTimeout:3.0 forCondition:^BOOL() {
            return requestCompleted;
        }];
    });
    it(@"includes the related objects in the response", ^{
        [[[apiResponse objectForKey:@"children"] should] containObjects:@"foo", @"bar", @"baz", nil];
    });
});

SPEC_END

KWSpec+WaitFor.h

#import "KWSpec.h"

@interface KWSpec (WaitFor)

+ (void) waitWithTimeout:(NSTimeInterval)timeout forCondition:(BOOL(^)())conditionalBlock;

@end

KWSpec+WaitFor.m

#import "KWSpec+WaitFor.h"

@implementation KWSpec (WaitFor)

+ (void) waitWithTimeout:(NSTimeInterval)timeout forCondition:(BOOL(^)())conditionalBlock {
    NSDate *timeoutDate = [[NSDate alloc] initWithTimeIntervalSinceNow:timeout];
    while (conditionalBlock() == NO) {
        if ([timeoutDate timeIntervalSinceDate:[NSDate date]] < 0) {
            return;
        }
        [[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.1]];
    }
}

@end

Jonah, first of all thank you for posting this. It was a huge help.

You might want to update the example_test.m to the following so that anyone who tries to implement your example will not run into issues with failing tests....

describe(@"it takes a while", ^{
    __block NSDictionary *apiResponse = nil;
    beforeAll(^{
        __block BOOL requestCompleted = NO;    
        AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request 
            success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
                requestCompleted = YES;
                apiResponse = JSON;
            } 
            failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
                requestCompleted = YES;
            }
        ];
        [operation start];

        [KWSpec waitWithTimeout:3.0 forCondition:^BOOL() {
            return requestCompleted;
        }];
    });
    it(@"includes the related objects in the response", ^{
        [[[apiResponse objectForKey:@"children"] should] containObjects:@"foo", @"bar", @"baz", nil];
    });
});

Please note the new name of the local variable that will receive the JSON response... apiResponse. This is to avoid an issue where response = JSON; was setting the NSHTTPURLResponse *response which is a param in the success block of the AFJSONRequestOperation and ultimately leading to failing tests.

@atljeremy thanks for catching that. Sorry I gave you a poor example. I've applied your change so hopefully you've saved everyone else from similar confusion.