Question

我在iOS中单元测试异步调用时遇到问题。（虽然它在视图控制器中工作正常。）

以前有人遇到过这个问题吗？我尝试过使用等待功能，但我仍然遇到同样的问题。

请提供一个很好的方法来举例说明。

Answer 1

您需要旋转runloop，直到调用回调。但要确保它在主队列上被调用。

试试这个：

__block BOOL done = NO;
doSomethingAsynchronouslyWithBlock(^{
    done = YES;
});

while(!done) {
   [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
}

您也可以使用信号量（下面的示例），但我更喜欢旋转runloop以允许处理分派到主队列的异步块。

dispatch_semaphore_t sem = dispatch_semaphore_create(0);
doSomethingAsynchronouslyWithBlock(^{
    //...
    dispatch_semaphore_signal(sem);
});

dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);

Answer 2

以下是Apple's description对异步测试的原生支持。

TL; DR手册：

查看XCTextCase+AsynchronousTesting.h

特殊课程XCTestExpectation只有一种公共方法：- (void)fulfill;

您应该初始化此类的实例，并在成功案例中调用fulfill方法。否则，您在该方法中指定的超时后测试将失败：

- (void)waitForExpectationsWithTimeout:(NSTimeInterval)timeout handler:(XCWaitCompletionHandler)handlerOrNil;

示例：

- (void)testAsyncMethod
{

    //Expectation
    XCTestExpectation *expectation = [self expectationWithDescription:@"Testing Async Method Works Correctly!"];

    [MyClass asyncMethodWithCompletionBlock:^(NSError *error) {        
        if(error)
            NSLog(@"error is: %@", error);
        else
            [expectation fulfill];
    }];

    //Wait 1 second for fulfill method called, otherwise fail:    
    [self waitForExpectationsWithTimeout:1 handler:^(NSError *error) {

        if(error)
        {
            XCTFail(@"Expectation Failed with error: %@", error);
        }

    }];
}

Answer 3

我认为这篇文章中的许多建议解决方案存在的问题是，如果异步操作未完成，则永远不会设置“done”标志，并且测试将永久挂起。

我在很多测试中都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;
}

Answer 4

从Xcode 6开始，它作为一个类别内置于XCTest：

请参阅https://stackoverflow.com/a/24705283/88164

Answer 5

AGAsyncTestHelper是一个C宏，用于使用异步操作编写单元测试，并与SenTestingKit和XCTest一起使用。

简单而重要

- (void)testAsyncBlockCallback
{
    __block BOOL jobDone = NO;

    [Manager doSomeOperationOnDone:^(id data) {
        jobDone = YES; 
    }];

    WAIT_WHILE(!jobDone, 2.0);
}

Answer 6

这是另一个替代方案XCAsyncTestCase，如果你需要使用它，它可以很好地与OCMock配合使用。它基于GHUnit的异步测试程序，但使用的是常规的XCTest框架。与Xcode Bots完全兼容。

https://github.com/iheartradio/xctest-additions

用法是相同的，只需导入和子类XCAsyncTestCase。

@implementation TestAsync
- (void)testBlockSample
{
    [self prepare];
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(){
        sleep(1.0);
        [self notify:kXCTUnitWaitStatusSuccess];
    });
    // Will wait for 2 seconds before expecting the test to have status success
    // Potential statuses are:
    //    kXCTUnitWaitStatusUnknown,    initial status
    //    kXCTUnitWaitStatusSuccess,    indicates a successful callback
    //    kXCTUnitWaitStatusFailure,    indicates a failed callback, e.g login operation failed
    //    kXCTUnitWaitStatusCancelled,  indicates the operation was cancelled
    [self waitForStatus:kXCTUnitWaitStatusSuccess timeout:2.0];
}

Answer 7

Sam Brodkin已经提供了right answer。

为了让答案看起来更好看，我在这里提供示例代码。

使用XCTestExpectation。

// Test that the document is opened. Because opening is asynchronous,
// use XCTestCase's asynchronous APIs to wait until the document has
// finished opening.

- (void)testDocumentOpening
{
    // Create an expectation object.
    // This test only has one, but it's possible to wait on multiple expectations.
    XCTestExpectation *documentOpenExpectation = [self expectationWithDescription:@"document open"];

    NSURL *URL = [[NSBundle bundleForClass:[self class]]
                            URLForResource:@"TestDocument" withExtension:@"mydoc"];
    UIDocument *doc = [[UIDocument alloc] initWithFileURL:URL];
    [doc openWithCompletionHandler:^(BOOL success) {
        XCTAssert(success);
        // Possibly assert other things here about the document after it has opened...

        // Fulfill the expectation-this will cause -waitForExpectation
        // to invoke its completion handler and then return.
        [documentOpenExpectation fulfill];
    }];

    // The test will pause here, running the run loop, until the timeout is hit
    // or all expectations are fulfilled.
    [self waitForExpectationsWithTimeout:1 handler:^(NSError *error) {
        [doc closeWithCompletionHandler:nil];
    }];
}

Answer 8

我建议您查看tests of Facebook-ios-sdk。这是如何在iOS上测试异步单元测试的一个很好的例子，尽管我个人认为异步测试应该进入同步测试。

FBTestBlocker ：阻止当前线程以指定的超时退出的阻止程序。您可以将其拖放到项目中，但如果您没有在项目中使用，则需要删除与OCMock相关的内容。

FBTestBlocker.h

FBTestBlocker.m

FBURLConnectionTests ：您应该看一下测试示例。

FBURLConnectionTests.h

FBURLConnectionTests.m

此代码段应该为您提供一些想法

- (void)testExample
{
    FBTestBlocker *_blocker = [[FBTestBlocker alloc] initWithExpectedSignalCount:1];
    __block BOOL excuted = NO;
    [testcase test:^(BOOL testResult) {
        XCTAssert(testResult, @"Should be true");
        excuted = YES;
        [_blocker signal];
    }];

    [_blocker waitWithTimeout:4];
    XCTAssertTrue(excuted, @"Not executed");
}

Answer 9

你可以像swift一样在swift中使用异步api调用

private let serverCommunicationManager : ServerCommunicationManager = {
    let instance = ServerCommunicationManager()
    return instance
}()

var expectation:XCTestExpectation?
func testAsyncApiCall()  {
    expectation = self.expectation(description: "async request")

    let header = ["Authorization":"eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImp0aSI6ImQ4MmY1MTcxNzI4YTA5MjI3NWIzYWI3OWNkOTZjMGExOTI4MmM2NDEyZjMyYWQzM2ZjMzY4NmU2MjlhOWY2YWY1NGE0MDI4MmZiNzY2NWQ3In0.eyJhdWQiOiIxIiwianRpIjoiZDgyZjUxNzE3MjhhMDkyMjc1YjNhYjc5Y2Q5NmMwYTE5MjgyYzY0MTJmMzJhZDMzZmMzNjg2ZTYyOWE5ZjZhZjU0YTQwMjgyZmI3NjY1ZDciLCJpYXQiOjE1MDg4MjU1NTEsIm5iZiI6MTUwODgyNTU1MSwiZXhwIjoxNTQwMzYxNTUxLCJzdWIiOiIiLCJzY29wZXMiOltdfQ.osoMQgiY7TY7fFrh5r9JRQLQ6AZhIuEbrIvghF0VH4wmkqRUE6oZWjE5l0jx1ZpXsaYUhci6EDngnSTqs1tZwFTQ3srWxdXns2R1hRWUFkAN0ri32W0apywY6BrahdtiVZa9LQloD1VRMT1_QUnljMXKsLX36gXUsNGU6Bov689-bCbugK6RC3n4LjFRqJ3zD9gvkRaODuOQkqsNlS50b5tLm8AD5aIB4jYv3WQ4-1L74xXU0ZyBTAsLs8LOwvLB_2B9Qdm8XMP118h7A_ddLo9Cyw-WqiCZzeZPNcCvjymNK8cfli5_LZBOyjZT06v8mMqg3zszWzP6jOxuL9H1JjBF7WrPpz23m7dhEwa0a-t3q05tc1RQRUb16W1WhbRJi1ufdMa29uyhX8w_f4fmWdAnBeHZ960kjCss98FA73o0JP5F0GVsHbyCMO-0GOHxow3-BqyPOsmcDrI4ay006fd-TJk52Gol0GteDgdntvTMIrMCdG2jw8rfosV6BgoJAeRbqvvCpJ4OTj6DwQnV-diKoaHdQ8vHKe-4X7hbYn_Bdfl52gMdteb3_ielcVXIaHmQ-Dw3E2LSVt_cSt4tAHy3OCd7WORDY8uek4Paw8Pof0OiuqQ0EB40xX5hlYqZ7P_tXpm-W-8ucrIIxgpZb0uh-wC3EzBGPjpPD2j9CDo"]
    serverCommunicationManager.sendServerRequest(httpMethodType: .get, baseURL: "http://192.168.2.132:8000/api/v1/user-role-by-company-id/2", param: nil, header: header) { (isSuccess, msg , response) in
        if isSuccess
        {
            let array = response as! NSArray

            if  array.count == 8
            {
                XCTAssertTrue(true)
                self.expectation?.fulfill()
            }
            else
            {
                XCTAssertFalse(false)
                XCTFail("array count fail")
            }
        }
    }
    waitForExpectations(timeout: 5) { (error) in
        if let error = error{
            XCTFail("waiting with error: \(error.localizedDescription)")
        }
    }
}

Answer 10

我建议你连接信号量+ runloop，我也写了一个带块的方法：

// Set the flag to stop the loop
#define FLEND() dispatch_semaphore_signal(semaphore);

// Wait and loop until flag is set
#define FLWAIT() WAITWHILE(dispatch_semaphore_wait(semaphore, DISPATCH_TIME_NOW))

// Macro - Wait for condition to be NO/false in blocks and asynchronous calls
#define WAITWHILE(condition) \
do { \
while(condition) { \
[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate dateWithTimeIntervalSinceNow:1]]; \
} \
} while(0)

方法：

typedef void(^FLTestAsynchronousBlock)(void(^completion)(void));

void FLTestAsynchronous(FLTestAsynchronousBlock block) {
    FLSTART();
    block(^{
        FLEND();
    });
    FLWAIT();
};

并致电

FLTestAsynchronous(^(void(^completion)()){

    [networkManager signOutUser:^{
        expect(networkManager.currentUser).to.beNil();
        completion();
    } errorBlock:^(NSError *error) {
        expect(networkManager.currentUser).to.beNil();
        completion();
    }];

});

Answer 11

尝试KIWI框架。它功能强大，可以帮助您进行其他类型的测试。

Answer 12

如果您使用的是XCode 6，则可以像这样测试异步网络呼叫：

XCTest and asynchronous testing in Xcode 6

在iOS中测试单元测试中的异步调用

12 个答案: