ios - 如何测试在主线程上异步运行的方法？

Question

我只是有一个方法:

func update(with process: PresentableProcess) {
    presentableProcess = process
    if isViewLoaded {
        DispatchQueue.main.async { [weak self] in
            //do something on the main thread
        }
    }
}

及其测试:

func testPreferredContentSizeWhenTitleExist() {
    let process = PresentableProcess(title: "title")
    sut.update(with: process)

    XCTAssertEqualWithAccuracy(sut.preferredContentSize, 95, accuracy: 10)
}

它不起作用，因为它在主线程上运行。我想避免在 update(with)中添加完成块以通过测试。

Answer 1

恐怕您将需要使用完成块。要测试异步功能，请使用期望值

let expectation = expectation(description: "expectation")

doStuffWithCompletion() {
    expectation.fulfill()
}

waitForExpectations(timeout: 10) { error in
    //
}