swift - 由于 ""错误 -25204 获取元素的快照，XCUI 测试在 iOS 10 上失败但在 iOS 9 上失败”

Question

我已经为我的应用程序创建了一个用于 XCUItesting 的测试套件...但是自升级(不确定是否相关)到 xcode 8 和使用 ios10 模拟器后，我的测试用例将仅在 ios9 而不是 10 中运行。当我在 ios 10 模拟器中运行测试时，出现错误 Assertion Failure: <unknown>:0: UI Testing Failure - Failure getting snapshot Error Domain=XCTestManagerErrorDomain Code=9 "Error -25204 getting snapshot for element <AXUIElement 0x7fe2a6614ad0> {pid=7751}" UserInfo={NSLocalizedDescription=Error -25204 getting snapshot for element <AXUIElement 0x7fe2a6614ad0> {pid=7751}}

有没有人也遇到过这个？ 或者 有谁知道我哪里出错了？

非常感谢

Answer 1

根本原因

我遇到了同样的问题。测试失败并出现相同的错误，但根本原因是应用程序崩溃了。我设置了一个异常断点并打印回溯以查看位置。

最终，这是由于 uitableviewdelegate 的方法签名之一中的隐式解包可选导致的崩溃:

public func tableView(_ tableView: UITableView, canPerformAction action: Selector, forRowAt indexPath: IndexPath, withSender sender: Any?) -> Bool

该方法在UI测试时被系统调用，indexPath参数为nil，导致应用挂起。

回溯显示:

(lldb) thread backtrace
* thread #1: tid = 0x128eaa, 0x000000010c776c3a libswiftFoundation.dylib`static Foundation.IndexPath._unconditionallyBridgeFromObjectiveC (Swift.Optional<__ObjC.NSIndexPath>) -> Foundation.IndexPath + 42, queue = 'com.apple.main-thread', stop reason = EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)
  * frame #0: 0x000000010c776c3a libswiftFoundation.dylib`static Foundation.IndexPath._unconditionallyBridgeFromObjectiveC (Swift.Optional<__ObjC.NSIndexPath>) -> Foundation.IndexPath + 42
    frame #1: 0x0000000108443241 Static`@objc DataSource.tableView(UITableView, canPerformAction : Selector, forRowAt : IndexPath, withSender : Any?) -> Bool + 97 at DataSource.swift:0
    frame #2: 0x00000001095aea31 UIKit`-[UITableView _canPerformAction:forCell:sender:] + 169
    frame #3: 0x00000001098017c6 UIKit`-[UITableViewCell canPerformAction:withSender:] + 86
    frame #4: 0x00000001210a5fc9 UIKit`-[UIResponder(UITextAccessibilityUtilities) _accessibilityHasTextOperations] + 100
    frame #5: 0x000000012107bb7c UIKit`-[UITableViewCellAccessibilityElement _accessibilityHasTextOperations] + 48
    frame #6: 0x00000001211f09ec UIAccessibility`-[NSObject(AXPrivCategory) accessibilityAttributeValue:] + 5945
    frame #7: 0x000000012120bc04 UIAccessibility`_accessibilityAttributesForObject + 767
    frame #8: 0x000000012120b5e8 UIAccessibility`-[NSObject(UIAccessibilityAutomation) _accessibilityUserTestingSnapshotDescendantsWithAttributes:maxDepth:maxChildren:maxArrayCount:] + 1736
    frame #9: 0x000000012120cf96 UIAccessibility`-[NSObject(UIAccessibilityAutomation) _accessibilityUserTestingSnapshotWithOptions:] + 557
    frame #10: 0x00000001211eec0a UIAccessibility`-[NSObject(AXPrivCategory) accessibilityAttributeValue:forParameter:] + 7903
    frame #11: 0x00000001211d8856 UIAccessibility`_copyParameterizedAttributeValueCallback + 211
    frame #12: 0x0000000120869532 AXRuntime`_AXXMIGCopyParameterizedAttributeValue + 216
    frame #13: 0x0000000120863f1c AXRuntime`_XCopyParameterizedAttributeValue + 440
    frame #14: 0x0000000120872de5 AXRuntime`mshMIGPerform + 266
    frame #15: 0x00000001064e93d9 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 41
    frame #16: 0x00000001064e9351 CoreFoundation`__CFRunLoopDoSource1 + 465
    frame #17: 0x00000001064e1435 CoreFoundation`__CFRunLoopRun + 2389
    frame #18: 0x00000001064e0884 CoreFoundation`CFRunLoopRunSpecific + 420
    frame #19: 0x000000010e5bda6f GraphicsServices`GSEventRunModal + 161
    frame #20: 0x000000010943dc68 UIKit`UIApplicationMain + 159
    frame #21: 0x000000010462c95f GoOut`main + 111 at AppDelegate.swift:47
    frame #22: 0x000000010cb7e68d libdyld.dylib`start + 1
    frame #23: 0x000000010cb7e68d libdyld.dylib`start + 1

解决方案

在知道是哪个方法导致它之后，修复非常简单——只需将 indexPath 类型替换为可选的 IndexPath?(添加问号):

public func tableView(_ tableView: UITableView, canPerformAction action: Selector, forRowAt indexPath: IndexPath?, withSender sender: Any?) -> Bool

然后使用 nil 正确调用该方法并且不会导致崩溃。

有关详细信息，请参阅:https://openradar.appspot.com/31375101并随意欺骗雷达。