在iOS单元测试中模拟NSHTTPURLRequest和NSHTTPURLResponse

Question

我正在iOS中开发一个框架，它对服务器进行HTTP调用。我想编写单元测试来测试API。我想模拟服务器调用，而不是实际调用真正的服务器。任何人都可以帮我进行样本单元测试制作模拟服务器调用。如何设置期望并返回手工构建的url响应。我使用XCTest框架进行单元测试，使用OCMock进行模拟对象。

Answer 1

Here is how you might mock sendAsynchronousRequest:

NSDictionary *serverResponse = @{ @"response" : [[NSHTTPURLResponse alloc] initWithURL:nil statusCode:200 HTTPVersion:nil headerFields:@{}],
                                  @"data" : [@"SOMEDATA" dataUsingEncoding:NSUTF8StringEncoding]
                                  };

id connectionMock = [OCMockObject mockForClass:NSURLConnection.class];
[[[connectionMock expect] andDo:^(NSInvocation *invocation) {
    void (^handler)(NSURLResponse*, NSData*, NSError*);
    handler = [invocation getArgumentAtIndexAsObject:4];
    handler(serverResponse[@"response"], serverResponse[@"data"], serverResponse[@"error"]);
}] sendAsynchronousRequest:OCMOCK_ANY queue:OCMOCK_ANY completionHandler:OCMOCK_ANY];

EDIT

To add clarification, here's what's happening. In this example our real code is calling [NSURLConnection sendAsynchronousRequest: queue: completionHandler:] There are three arguments passed to this method, plus the additional _cmd and self that is passed to all Objective-C method calls. Thus when we examine our NSInvocation the argument at index 4 is our completion handler. Since we are simulating the response from the server, we want to call this handler with fake data that represents the case we are testing.

The signature for the method call getArgumentAtIndexAsObject is in a header file included with OCMock, but is not included by default in the framework. I believe it is called NSInvocation+OCMAdditions.h . It makes fetching the invocation arguments easier by returning an id .

Answer 2

Use OHTTPStubs, https://github.com/AliSoftware/OHHTTPStubs .

Here's a practical example of mocking the response to a specific GET request and returning JSON data.

[OHHTTPStubs stubRequestsPassingTest:^BOOL(NSURLRequest *request) {
    return [request.URL.path isEqualToString:@"/api/widget"];
} withStubResponse:^OHHTTPStubsResponse *(NSURLRequest *request) {
    id JSON = @{ @"id": @"1234", @"name" : @"gadget" };
    NSData *data = [NSJSONSerialization dataWithJSONObject:JSON options:0 error:nil];
    return [OHHTTPStubsResponse responseWithData:data statusCode:200 headers:@{ @"Content-Type": @"application/json" }];
}];