在iOS中测试单元测试中的异步调用

我认为这个帖子中的许多建议的解决方案有一个问题,如果异步操作不完成,“完成”标志永远不会设置,测试将永久挂起.

我在许多测试中已经成功地使用了这种方法.

- (void)testSomething {
    __block BOOL done = NO;

    [obj asyncMethodUnderTestWithCompletionBlock:^{
        done = YES;
    }];

    XCTAssertTrue([self waitFor:&done timeout:2],@"Timed out waiTing for response asynch method completion");
}


- (BOOL)waitFor:(BOOL *)flag timeout:(NSTimeInterval)timeoutSecs {
    NSDate *timeoutDate = [NSDate dateWithTimeIntervalSinceNow:timeoutSecs];

    do {
        [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:timeoutDate];
        if ([timeoutDate timeIntervalSinceNow] < 0.0) {
            break;
        }
    }
    while (!*flag);
    return *flag;
}