Testing asynchronous methods with Kiwi

gistfile1.m

//
//  BeerTests.m
//  Beer
//
//  Created by Marin Usalj on 5/16/13.
//  Copyright 2013 @mneorr | mneorr.com. All rights reserved.
//

#import "Kiwi.h"


@implementation NSObject(tests)

+ (void)bringBeersFromTheFridge:(void (^)(NSArray *))beers {
    
    [[NSOperationQueue new] addOperationWithBlock:^{
        
        sleep(3); // run to the fridge
        sleep(1); // open the fridge
        sleep(2); // grab beers
        sleep(1); // close the fridge
        sleep(3); // run back
        
        
        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
            beers(@[@"Delirium", @"Leffe", @"Chimay"]);
        }];
    }];
}

@end


SPEC_BEGIN(Async)

describe(@"Async tests", ^{
    
    __block NSArray *coldBeers;
    __block void (^passedBlock)(NSArray *);
    
    beforeEach(^{
        KWCaptureSpy *spy = [NSObject captureArgument:@selector(bringBeersFromTheFridge:) atIndex:0];
        [NSObject bringBeersFromTheFridge:^(NSArray *beers) {
            coldBeers = beers;
        }];
        passedBlock = spy.argument;
    });
    
    //  This is an obvious example with an NSObject. __Notice how much faster the first 2 specs are__.
    //  You have the complete control of what the block returns, and you can test against many cases.

    it(@"has a fast async test", ^{
        passedBlock(@[@"Delirium", @"Chimay"]);
        [[coldBeers should] haveCountOf:2];
    });
    
    it(@"can bring as much beer as you tell him in the test, regardless of the count in the fridge", ^{
        
        passedBlock(@[@"Delirium", @"Leffe", @"Chimay", @"Duvel", @"Kwak"]);
        [[coldBeers should] haveCountOf:5];
    });
    
    it(@"has slow async test. you're thirsty and want tese beers now.", ^{
        [NSObject bringBeersFromTheFridge:^(NSArray *beers) {
            coldBeers = beers;
        }];
        
        // sometimes async requests take longer, so you need to increase the expected time. this one fails.
        [[expectFutureValue(coldBeers) shouldEventually] haveCountOf:3]; 
        [[expectFutureValue(coldBeers) shouldEventuallyBeforeTimingOutAfter(10)] haveCountOf:3];
    });
    
});

SPEC_END