swift - Xcode 11 : _XCTestCaseInterruptionException when using XCUIElement waitForExistence

Question

我目前正在使用标准 XCUIElement 函数 waitForExistence(timeout: TimeInterval) 以等待按钮出现。我总是将超时设置为大于 2.0 秒，但一直遇到同样的问题。

Assertion Failure: Failed to get matching snapshots: Unable to perform work on main run loop, process main thread busy for 2.0s - recommend retry by client *** Terminating app due to uncaught exception '_XCTestCaseInterruptionException', reason: 'Interrupting test'

这太令人沮丧了，因为这开始发生在 Xcode 11 及更高版本上。更糟糕的是，您无法捕获异常，因为 waitForExistence 方法设置为从不抛出异常。关于如何捕捉这个的任何想法？被定位的元素只是 XCUIApplication().buttons["id"]，所以它应该很好用。当应用程序正在检索数据时，不应与主线程断开连接。

Answer 1

我在始终有效的 UI 测试中使用自定义等待(我为 XCTestCase 创建了一个扩展):

public class var defaultTimeOut: TimeInterval { return 5 }

public func wait(forFulfillmentOf predicate: NSPredicate,
                 for element: XCUIElement,
                 withFailingMessage message: String = "Failed to fulfill predicate %@ for %@ within %.2f seconds.",
                 timeout: TimeInterval = XCTestCase.defaultTimeOut,
                 file: StaticString = #file,
                 line: UInt = #line) {

    expectation(for: predicate, evaluatedWith: element, handler: nil)

    waitForExpectations(timeout: timeout) { (error) -> Void in
        guard error != nil else {
            return
        }
        let failingMessage = String(format: message, arguments: [predicate, element, timeout])
        self.recordFailure(withDescription: failingMessage, inFile: String(describing: file), atLine: Int(clamping: line), expected: true)
    }
}

然后你可以在 UI 测试中实际使用这个方法:

public func wait(forExistanceOf element: XCUIElement, timeout: TimeInterval = XCTestCase.defaultTimeOut, file: StaticString = #file, line: UInt = #line) {
    let existancePredicate = NSPredicate(format: "exists == true")
    wait(forFulfillmentOf: existancePredicate, for: element, withFailingMessage: "Failed to find %2$@ within %3$.2f seconds. Predicate was: %1$@.", timeout: timeout, file: file, line: line)
}

希望这可以帮助!