Test suite: avoid calling the fulfill after the wait context has ended

[ricardopereira]

I declared each expectation variable as __weak to avoid API violations. The expectation will be released when the timeout expires. So if the task takes longer than the timeout, the expectation variable will be nil when the task completion handler is called. Thus the fulfill method will be called on nil, doing nothing.

[tcard]

Doesn't assigning a freshly allocated object to a weak variable just deallocate the object right away?

From a quick test:

 10> func test() { 
 11.     weak var x = NSString(string: "not nil") 
 12.     print(x) 
 13. }    
 14> test()
nil

[ricardopereira]

Yes, that's my point but it will wait because of the waitForExpectationsWithTimeout. So the expectation variable is available until the fullfill or the timeout.

[ricardopereira]

Can I merge?

[tcard]

I mean that, unless I'm mistaken, the expectation variable will never be not nil. I think the snippet I pasted above proves that; x is immediately nil after assigning it.

[ricardopereira]

Yes, correct. In your example the instance has no strong reference but when you create an expectation __weak XCTestExpectation *expectation = [self expectationWithDescription:@"testCase"]; it will have a strong reference. Although not clearly documented, the expectation will be released when the timeout expires. You can check the reference count with [expectation retainCount]:

2016-03-17 08:25:34.155 xctest[59800:9879713] ------- testSubscribeToName
(lldb) po [exp retainCount]
2

Thus there are two references to it. I don't know if one of them is a strong but I tested it and it's working as expected:

- (void)testSubscribeToName {
    __weak XCTestExpectation *expectation = [self expectationWithDescription:@"testSubscribeToName"];
    NSString *channelName = @"channel";
    [ARTTestUtil testRealtime:^(ARTRealtime *realtime) {
        NSLog(@"------- %@", expectation);
        _realtime = realtime;
        ARTRealtimeChannel *channel = [realtime.channels get:channelName];
        [expectation fulfill];
    }];
    [self waitForExpectationsWithTimeout:[ARTTestUtil timeout] handler:nil];
    NSLog(@"------- %@", expectation);
}

2016-03-17 08:25:34.155 xctest[59800:9879713] ------- testSubscribeToName
2016-03-17 08:25:34.156 xctest[59800:9879713] ------- testSubscribeToName

[tcard]

Ah, OK, of course, self should be retaining a reference to the expectation so that waitForExpectationsWithTimeout works. Sorry, just wanted to understand what's going on. LGTM then!