Delayed requests

[pcantrell]

A possible approach to #123.

This PR adds delay() and go() methods to the response DSL. This allows clients to do:

let reqStub = stubRequest("GET", "http://foo")
    .andReturn(200)
    .delay()

// trigger request
// make assertions here about state of things while request is in progress

reqStub.go()

// wait for response

This is an incomplete implementation:

• it’s only implemented for LSHTTPStubURLProtocol, and
• there are no specs.

@luisobo, let me know if you have thoughts about this approach. If so, I’ll update the PR with the full implementation.

[cianclarke]

+1 to this - nice work @pcantrell , I've also been wishing for this.
Could the same be achieved by passing an exception via andFailWithError? Either way, I think this would be nice to have

[pcantrell]

andFailWithError affects the content of the response, but not when it happens. This addition is all about timing, and is orthogonal to all the other aspects of the response.

[pcantrell]

Rebased for easy peasy merging fun.

FWIW, this code has been tested in the wild — in use on Siesta for the past 2 months, and working great. Here’s an example of how it plays out in practice:

https://github.com/bustoutsolutions/siesta/blob/master/Tests/ResourceRequestsSpec.swift#L109-L116

[lucaslt89]

+1 to this too! I've tested it and it works smoothly!

[aarsland]

+1 Would be excellent if this gets accepted and merged @luisobo .
@pcantrell I have found a problem with the implementation. It will also prevent subsequent requests from responding.

- (void)testThatDelayDoesNotInterruptAllRequests
{
    NSData *bodyData = [@"Body content" dataUsingEncoding:NSUTF8StringEncoding];

    LSStubResponseDSL *stub = stubRequest(@"GET", @"http://a-url").andReturn(200).delay();

    stubRequest(@"GET", @"http://b-url").andReturn(200).withBody(bodyData);

    __block NSData *dataFromResponse = nil;

    XCTestExpectation *expectation = [self expectationWithDescription:@"Wait for network"];

    // This line will prevent all request to finish, not only the intended request.
    [[[NSURLSession sharedSession] dataTaskWithURL:[NSURL URLWithString:@"http://a-url"]
                                 completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
                                 }] resume];

    [[[NSURLSession sharedSession] dataTaskWithURL:[NSURL URLWithString:@"http://b-url"]
            completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
                [stub go];
                dataFromResponse = data;
                [expectation fulfill];
            }] resume];

    [self waitForExpectationsWithTimeout:2 handler:nil];
    XCTAssert([dataFromResponse isEqualToData:bodyData]);
}

[andrewkboyd]

This seems reasonable, however in the meantime OS X and tvOS targets have been added to the master. If you rebase we should be able to make the merge easy and I can pull it in.

Seems simple and makes sense.

[pcantrell]

Rebased against latest master. Specs pass.

In successful use now for many months a year on Siesta.