A custom NSURLProtocol doesn't invoke canInitWithRequest:

Question

I've implemented a subclass of NSURLProtocol. I need it to mock URL responses for a unit test. I've registered my class in the setUp method of the unit test.

- (void)setUp
{
    [NSURLProtocol registerClass:[RDMockResponseURLProtocol class]];

    [DSMockResponseURLProtocol.mockResponses setObject:[self bigFileResponse]
                                                forKey:[self bigFileURL]];

    <...>
}

I've overridden the class method canInitWithRequest: of NSURLProtocol and its other methods required to be overridden.

@implementation DSMockResponseURLProtocol

<...>

+ (BOOL)canInitWithRequest:(NSURLRequest *)request {
    return [DSMockResponseURLProtocol.mockResponses.allKeys containsObject:request.URL];
}

Unfortunately canInitWithRequest: isn't being invoked.

I use NSURLSession configured to continue tasks in the background mode. Isn't it causing the issue?

sessionConfiguration = [NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier:identifier];

Please share with me any ideas you have! Thanks in advance [Bow]

score 0 · Accepted Answer · answered Dec 17 '19 at 17:28

0

It seems like I have found the answer in the documentation.

You cannot use custom URLProtocol subclasses in conjunction with background sessions.

https://developer.apple.com/documentation/foundation/urlsessionconfiguration/1411050-protocolclasses

answered Dec 17 '19 at 17:28

Dmytro Skorokhod

424
8
17

1

Right. Background sessions are run in a separate process, and there's no good way for code running in that background daemon to be so tightly coupled with code running in your app. – dgatwood Jan 02 '20 at 00:35

A custom NSURLProtocol doesn't invoke canInitWithRequest:

1 Answers1