gistfile1.m

@implementation ADNClient

+ (id)sharedClient
{
    static dispatch_once_t pred = 0;
    __strong static id _sharedObject = nil;
    dispatch_once(&pred, ^{
        _sharedObject = [[self alloc] init];
    });
    return _sharedObject;
}

- (id)init
{
    self = [super initWithBaseURL:[NSURL URLWithString:@"https://alpha-api.app.net/stream/0/posts/stream/global"]];
    if (self)
    {
        [self setUpToReceiveJSON];
    }
    return self;
}

- (void)setUpToReceiveJSON
{
    [self registerHTTPOperationClass:[AFJSONRequestOperation class]];
    [self setDefaultHeader:@"Accept" value:@"application/json"];
}

@end

gistfile2.m

#import <Kiwi/Kiwi.h>
#import "AFNetworking.h"
#import "ADNClient.h"

@interface ADNClient ()
- (void)setUpToReceiveJSON;
@end

SPEC_BEGIN(ADNClientSpec)

describe(@"An ADNClient", ^{
   
    __block ADNClient *client;
    
    beforeEach(^{
        client = [ADNClient sharedClient];
    });
    
    afterEach(^{
        client = nil;
    });
    
    context(@"when created", ^{
        
        it(@"should not be nil", ^{
    
            [client shouldNotBeNil];
            
        });
        
        it(@"should be a singleton", ^{
            ADNClient *newClient = [ADNClient sharedClient];
            [[newClient should] beIdenticalTo:client];
        });
        
        it(@"should be set up to handle JSON", ^{
            // err... ?
        });
        
    });
    
});

SPEC_END