Testing HTTP using Kiwi/Nocilla

Question

I just started developing an app that connects to this URL and retrieves the rate exchange for a given pair of currencies.

I need to test the HTTP request and I ended up learning about Kiwi and Nocilla. However, I'm completely new to any kind of testing and there's not a lot of information about Nocilla that can help me to get started.

I added all the NSURLConnectionDataDelegate and NSURLConnectionDelegate methods to the ViewController of my single view application, and the data retrieved from the URL is stored in @property (strong, nonatomic) NSMutableData *receivedData;. When I run the program everything works as expected but I haven't been able to pass the test I wrote:

SPEC_BEGIN(URLConnectionSpec)

__block URLConnectionAppDelegate *app_delegate;
__block URLConnectionViewController *view_controller;

describe(@"URLConnection", ^{
    beforeAll(^{
        [[LSNocilla sharedInstance] start];

        app_delegate = [[UIApplication sharedApplication] delegate];
        [[app_delegate shouldNot] beNil];
        view_controller = app_delegate.viewController;
    });

    afterAll(^{
        [[LSNocilla sharedInstance] stop];
    });

    afterEach(^{        
        [[LSNocilla sharedInstance] clearStubs];
    });

    context(@"When testing", ^{
        it(@"should do something", ^{
            stubRequest(@"GET", @"http://rate-exchange.appspot.com/currency?from=USD&to=EUR&q=1");

            [view_controller beginCommunication];

            [[expectFutureValue([NSString stringWithUTF8String:[view_controller.receivedData bytes]]) shouldEventuallyBeforeTimingOutAfter(2)] equal:@"{\"to\": \"EUR\", \"rate\": 0.76610740799999999, \"from\": \"USD\", \"v\": 0.76610740799999999}"];
        });
    });
});

SPEC_END

I'm sorry for the long snippet of code.

The test always failed with this message

URLConnection_WhenTesting_ShouldDoSomething] : 'URLConnection, When testing, should do something' [FAILED], expected subject to equal "{"to"： "EUR", "rate"： 0.76610740799999999, "from"： "USD", "v"： 0.76610740799999999}", got ""

I tried changing the time to even 10 seconds hoping that the test finished too early but I got the same results. I don't know why 'receivedData' is empty.

I would really appreciate any help

The general structure of the Kiwi test looks ok. Can you show the code for `stubRequest`? And are you certain that all of your variables (`view_controller`, etc.) are non-nil? — Mike Mertsock, Jul 02 '13 at 12:59
Thanks for your reply. `stubRequest` is part of [Nocilla](https://github.com/luisobo/Nocilla), I didn't implemented myself. All the variables in view_controller are initialized to nil, and the `NSMutableData` that contains the data received from the URL is initialized in `connectionDidFinishLoading:connection`. However I don't know why just when testing, this function or any other related related with `NSURLConnectionDelegate` or `NSURLConnectionDataDelegate`, aren't being called. — Diego A. Rincon, Jul 03 '13 at 01:10
The code for `stubRequest` looks pretty reasonable, looks like that should work fine with Kiwi since it just operates on `LSNocilla sharedInstance`. Could you try stepping through the debugger or adding some `NSLog` statements to `beginCommunication`? — Mike Mertsock, Jul 03 '13 at 01:29
I cannot believe I made such mistake...The whole point of using `stubRequest` is to simulate the connection to an URL, which means, during testing the app will "connect" to `stubRequest` and since this function does not return the same data the real URL does, well...I think you see the problem in here. After using NSLog as you suggested I could see that everything was working how it was supposed to. Would you mind writing your comment as an answer so I can check it? Thanks! — Diego A. Rincon, Jul 03 '13 at 01:48

score 1 · Accepted Answer · answered Jul 03 '13 at 01:51

See discussion in comments: the overall structure of the Kiwi test looks good, the Nocilla stubRequest function call doesn't seem to result in the response that the test is expecting.

Perhaps you could use andReturnRawResponse to set up the expected response data. Something like this (assuming I got the Nocilla syntax correct):

NSData *rawData = ...
stubRequest(...).andReturnRawResponse(rawData);
[view_controller beginCommunication];
[expectFutureValue([view_controller.receivedData bytes])
  shouldEventuallyBeforeTimingOutAfter(2)] equal:rawData.bytes];

Testing HTTP using Kiwi/Nocilla

1 Answers1