chore: Handle app startup errors as session creation exceptions

WebDriverAgent.xcodeproj/project.pbxproj

@@ -450,6 +450,10 @@
 		71A7EAF91E224648001DA4F2 /* FBClassChainQueryParser.h in Headers */ = {isa = PBXBuildFile; fileRef = 71A7EAF71E224648001DA4F2 /* FBClassChainQueryParser.h */; };
 		71A7EAFA1E224648001DA4F2 /* FBClassChainQueryParser.m in Sources */ = {isa = PBXBuildFile; fileRef = 71A7EAF81E224648001DA4F2 /* FBClassChainQueryParser.m */; };
 		71A7EAFC1E229302001DA4F2 /* FBClassChainTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 71A7EAFB1E229302001DA4F2 /* FBClassChainTests.m */; };
+		71AB65B32B8F156200187057 /* XCUIApplication+FBLaunch.h in Headers */ = {isa = PBXBuildFile; fileRef = 71AB65B12B8F156200187057 /* XCUIApplication+FBLaunch.h */; };
+		71AB65B42B8F156200187057 /* XCUIApplication+FBLaunch.h in Headers */ = {isa = PBXBuildFile; fileRef = 71AB65B12B8F156200187057 /* XCUIApplication+FBLaunch.h */; };
+		71AB65B52B8F156200187057 /* XCUIApplication+FBLaunch.m in Sources */ = {isa = PBXBuildFile; fileRef = 71AB65B22B8F156200187057 /* XCUIApplication+FBLaunch.m */; };
+		71AB65B62B8F156200187057 /* XCUIApplication+FBLaunch.m in Sources */ = {isa = PBXBuildFile; fileRef = 71AB65B22B8F156200187057 /* XCUIApplication+FBLaunch.m */; };
 		71ACF5B8242F2FDC00F0AAD4 /* FBSafariAlertTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 71ACF5B7242F2FDC00F0AAD4 /* FBSafariAlertTests.m */; };
 		71B155DA23070ECF00646AFB /* FBHTTPStatusCodes.h in Headers */ = {isa = PBXBuildFile; fileRef = 71B155D923070ECF00646AFB /* FBHTTPStatusCodes.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		71B155DC230711E900646AFB /* FBCommandStatus.m in Sources */ = {isa = PBXBuildFile; fileRef = 71B155DB230711E900646AFB /* FBCommandStatus.m */; };
@@ -1028,6 +1032,8 @@
 		71A7EAF71E224648001DA4F2 /* FBClassChainQueryParser.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = FBClassChainQueryParser.h; sourceTree = "<group>"; };
 		71A7EAF81E224648001DA4F2 /* FBClassChainQueryParser.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = FBClassChainQueryParser.m; sourceTree = "<group>"; };
 		71A7EAFB1E229302001DA4F2 /* FBClassChainTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = FBClassChainTests.m; sourceTree = "<group>"; };
+		71AB65B12B8F156200187057 /* XCUIApplication+FBLaunch.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "XCUIApplication+FBLaunch.h"; sourceTree = "<group>"; };
+		71AB65B22B8F156200187057 /* XCUIApplication+FBLaunch.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "XCUIApplication+FBLaunch.m"; sourceTree = "<group>"; };
 		71ACF5B7242F2FDC00F0AAD4 /* FBSafariAlertTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = FBSafariAlertTests.m; sourceTree = "<group>"; };
 		71B155D923070ECF00646AFB /* FBHTTPStatusCodes.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = FBHTTPStatusCodes.h; sourceTree = "<group>"; };
 		71B155DB230711E900646AFB /* FBCommandStatus.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = FBCommandStatus.m; sourceTree = "<group>"; };
@@ -1709,6 +1715,8 @@
 				71A5C67229A4F39600421C37 /* XCTIssue+FBPatcher.m */,
 				AD6C269A1CF2494200F8B5FF /* XCUIApplication+FBHelpers.h */,
 				AD6C269B1CF2494200F8B5FF /* XCUIApplication+FBHelpers.m */,
+				71AB65B12B8F156200187057 /* XCUIApplication+FBLaunch.h */,
+				71AB65B22B8F156200187057 /* XCUIApplication+FBLaunch.m */,
 				71C8E54F25399A6B008572C1 /* XCUIApplication+FBQuiescence.h */,
 				71C8E55025399A6B008572C1 /* XCUIApplication+FBQuiescence.m */,
 				716C9DFE27315EFF005AD475 /* XCUIApplication+FBUIInterruptions.h */,
@@ -2331,6 +2339,7 @@
 				641EE6882240C5CA00173FCB /* FBElement.h in Headers */,
 				641EE6892240C5CA00173FCB /* XCTAXClient-Protocol.h in Headers */,
 				641EE68B2240C5CA00173FCB /* FBExceptionHandler.h in Headers */,
+				71AB65B42B8F156200187057 /* XCUIApplication+FBLaunch.h in Headers */,
 				71822726258744AE00661B83 /* RoutingConnection.h in Headers */,
 				641EE68C2240C5CA00173FCB /* FBRoute.h in Headers */,
 				641EE68D2240C5CA00173FCB /* XCTestDriver.h in Headers */,
@@ -2662,6 +2671,7 @@
 				71930C4220662E1F00D3AFEC /* FBPasteboard.h in Headers */,
 				EE7E271C1D06C69F001BEC7B /* FBDebugLogDelegateDecorator.h in Headers */,
 				EEDFE1211D9C06F800E6FFE5 /* XCUIDevice+FBHealthCheck.h in Headers */,
+				71AB65B32B8F156200187057 /* XCUIApplication+FBLaunch.h in Headers */,
 				7155D703211DCEF400166C20 /* FBMjpegServer.h in Headers */,
 				EE35AD761E3B77D600A02D78 /* XCUIRecorderNodeFinderMatch.h in Headers */,
 				EE35AD6C1E3B77D600A02D78 /* XCUIApplicationProcess.h in Headers */,
@@ -3071,6 +3081,7 @@
 				641EE5EB2240C5CA00173FCB /* XCUIElement+FBFind.m in Sources */,
 				641EE5EC2240C5CA00173FCB /* FBResponsePayload.m in Sources */,
 				C845206322D5E79700EA68CB /* FBUnattachedAppLauncher.m in Sources */,
+				71AB65B62B8F156200187057 /* XCUIApplication+FBLaunch.m in Sources */,
 				641EE5ED2240C5CA00173FCB /* FBRoute.m in Sources */,
 				641EE5EE2240C5CA00173FCB /* NSString+FBVisualLength.m in Sources */,
 				641EE5EF2240C5CA00173FCB /* FBRunLoopSpinner.m in Sources */,
@@ -3216,6 +3227,7 @@
 				EE158AC51CBD456F00A3E3F0 /* FBOrientationCommands.m in Sources */,
 				716F0DA32A16CA1000CDD977 /* NSDictionary+FBUtf8SafeDictionary.m in Sources */,
 				71D475C42538F5A8008D9401 /* XCUIApplicationProcess+FBQuiescence.m in Sources */,
+				71AB65B52B8F156200187057 /* XCUIApplication+FBLaunch.m in Sources */,
 				641EE7082240CDEB00173FCB /* XCUIElement+FBTVFocuse.m in Sources */,
 				71E75E6F254824230099FC87 /* XCUIElementQuery+FBHelpers.m in Sources */,
 				71D04DCA25356C43008A052C /* XCUIElement+FBCaching.m in Sources */,

WebDriverAgentLib/Categories/XCUIApplication+FBLaunch.h

@@ -0,0 +1,34 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import <XCTest/XCTest.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface XCUIApplication (FBLaunch)
+
+/** This property must only be used internally */
+@property (nonatomic, nullable) NSNumber *fb_didStartWithoutBlockingAlert;
+
+/** This property must only be used internally */
+@property (nonatomic, nullable) NSString *fb_blockingAlertText;
+
+/**
+ * Launches the app with background blocking alert validation.
+ * This allows to avoid deadlocks or long timeouts on app startup.
+ * @param interval The amount of float ssconds between blocking alert presence checks
+ * @param error  The actual error if present
+ * @return YES in case of success
+ */
+- (BOOL)fb_launchWithInterruptingAlertCheckInterval:(NSTimeInterval)interval 
+                                              error:(NSError **)error;
+
+@end
+
+NS_ASSUME_NONNULL_END

WebDriverAgentLib/Categories/XCUIApplication+FBLaunch.m

@@ -0,0 +1,107 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import "XCUIApplication+FBLaunch.h"
+
+#import <objc/runtime.h>
+
+#import "FBAlert.h"
+#import "FBLogger.h"
+#import "FBErrorBuilder.h"
+#import "XCUIapplication.h"
+#import "XCUIApplication+FBAlert.h"
+#import "XCUIApplication+FBHelpers.h"
+
+@implementation XCUIApplication (FBLaunch)
+
+static char XCUIAPPLICATION_DID_START_WO_BLOCKING_ALERT;
+static char XCUIAPPLICATION_BLOCKING_ALERT_TEXT;
+
+@dynamic fb_didStartWithoutBlockingAlert;
+@dynamic fb_blockingAlertText;
+
+- (void)setFb_didStartWithoutBlockingAlert:(NSNumber *)didStartWithoutBlockingAlert
+{
+  objc_setAssociatedObject(self, &XCUIAPPLICATION_DID_START_WO_BLOCKING_ALERT, 
+                           didStartWithoutBlockingAlert, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+}
+
+- (NSNumber *)fb_didStartWithoutBlockingAlert
+{
+  return objc_getAssociatedObject(self, &XCUIAPPLICATION_DID_START_WO_BLOCKING_ALERT);
+}
+
+- (void)setFb_blockingAlertText:(NSString *)blockingAlertText
+{
+  objc_setAssociatedObject(self, &XCUIAPPLICATION_BLOCKING_ALERT_TEXT,
+                           blockingAlertText, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+}
+
+- (NSString *)fb_blockingAlertText
+{
+  return objc_getAssociatedObject(self, &XCUIAPPLICATION_BLOCKING_ALERT_TEXT);
+}
+
+- (void)fb_scheduleNextDispatchWithInterval:(NSTimeInterval)interval
+                                timeStarted:(uint64_t)timeStarted
+                                    timeout:(NSTimeInterval)timeout
+{
+  dispatch_time_t dispatchTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t) (interval * NSEC_PER_SEC));
+  dispatch_after(dispatchTime, dispatch_get_main_queue(), ^{
+    NSTimeInterval duration = (clock_gettime_nsec_np(CLOCK_MONOTONIC_RAW) - timeStarted) / NSEC_PER_SEC;
+    if ([self.fb_didStartWithoutBlockingAlert boolValue] || duration > timeout) {
+      return;
+    }
+
+    FBAlert *alert = nil;
+    @try {
+      XCUIElement *alertElement = [self.class.fb_systemApplication fb_alertElement];
+      if (nil != alertElement) {
+        alert = [FBAlert alertWithElement:alertElement];
+      }
+    } @catch (NSException *e) {
+      [FBLogger logFmt:@"Got an unexpected exception while checking for system alerts: %@\n%@", e.reason, e.callStackSymbols];
+    }
+    if (nil != alert) {
+      self.fb_blockingAlertText = alert.text;
+      [self terminate];
+      return;
+    }
+    [self fb_scheduleNextDispatchWithInterval:interval
+                                  timeStarted:timeStarted
+                                      timeout:timeout];
+  });
+}
+
+- (BOOL)fb_launchWithInterruptingAlertCheckInterval:(NSTimeInterval)interval
+                                              error:(NSError **)error
+{
+  self.fb_didStartWithoutBlockingAlert = @NO;
+  self.fb_blockingAlertText = nil;
+  [self fb_scheduleNextDispatchWithInterval:interval
+                                timeStarted:clock_gettime_nsec_np(CLOCK_MONOTONIC_RAW)
+                                    timeout:65.];
+  @try {
+    [self launch];
+    self.fb_didStartWithoutBlockingAlert = @YES;
+    return YES;
+  } @catch (NSException *e) {
+    if (nil == self.fb_blockingAlertText) {
+      self.fb_didStartWithoutBlockingAlert = @YES;
+      return [[[FBErrorBuilder builder]
+        withDescriptionFormat:@"The application '%@' cannot be launched because of an unexpected error: %@", self.bundleID, e.reason]
+       buildError:error];;
+    }
+  }
+  return [[[FBErrorBuilder builder]
+           withDescriptionFormat:@"The application '%@' cannot be launched because it is blocked by an unexpected system alert: %@", self.bundleID, self.fb_blockingAlertText]
+          buildError:error];;
+}
+
+@end

WebDriverAgentLib/Commands/FBSessionCommands.m

@@ -11,6 +11,7 @@
 
 #import "FBCapabilities.h"
 #import "FBConfiguration.h"
+#import "FBExceptions.h"
 #import "FBLogger.h"
 #import "FBProtocolHelpers.h"
 #import "FBRouteRequest.h"
@@ -20,6 +21,7 @@
 #import "FBActiveAppDetectionPoint.h"
 #import "FBXCodeCompatibility.h"
 #import "XCUIApplication+FBHelpers.h"
+#import "XCUIApplication+FBLaunch.h"
 #import "XCUIApplication+FBQuiescence.h"
 #import "XCUIDevice.h"
 #import "XCUIDevice+FBHealthCheck.h"
@@ -164,7 +166,11 @@ + (NSArray *)routes
           return FBResponseWithStatus([FBCommandStatus sessionNotCreatedError:errorMsg traceback:nil]);
         }
       } else {
-        [app launch];
+        NSError *launchError;
+        if (![app fb_launchWithInterruptingAlertCheckInterval:1. error:&launchError]) {
+          return FBResponseWithStatus([FBCommandStatus sessionNotCreatedError:launchError.description
+                                                                    traceback:nil]);
+        }
       }
       if (!app.running) {
         NSString *errorMsg = [NSString stringWithFormat:@"Cannot launch %@ application. Make sure the correct bundle identifier has been provided in capabilities and check the device log for possible crash report occurrences", bundleID];

WebDriverAgentLib/Routing/FBExceptionHandler.m

@@ -45,6 +45,9 @@ - (void)handleException:(NSException *)exception forResponse:(RouteResponse *)re
   } else if ([exception.name isEqualToString:FBTimeoutException]) {
     commandStatus = [FBCommandStatus timeoutErrorWithMessage:exception.reason
                                                    traceback:traceback];
+  } else if ([exception.name isEqualToString:FBSessionCreationException]) {
+    commandStatus = [FBCommandStatus sessionNotCreatedError:exception.reason
+                                                  traceback:traceback];
   } else {
     commandStatus = [FBCommandStatus unknownErrorWithMessage:exception.reason
                                                    traceback:traceback];

WebDriverAgentLib/Routing/FBExceptions.h

@@ -14,6 +14,9 @@ NS_ASSUME_NONNULL_BEGIN
 /*! Exception used to notify about missing session */
 extern NSString *const FBSessionDoesNotExistException;
 
+/*! Exception used to notify about session creation issues */
+extern NSString *const FBSessionCreationException;
+
 /*! Exception used to notify about application deadlock */
 extern NSString *const FBApplicationDeadlockDetectedException;
 

WebDriverAgentLib/Routing/FBExceptions.m

@@ -10,6 +10,7 @@
 #import "FBExceptions.h"
 
 NSString *const FBInvalidArgumentException = @"FBInvalidArgumentException";
+NSString *const FBSessionCreationException = @"FBSessionCreationException";
 NSString *const FBSessionDoesNotExistException = @"FBSessionDoesNotExistException";
 NSString *const FBApplicationDeadlockDetectedException = @"FBApplicationDeadlockDetectedException";
 NSString *const FBElementAttributeUnknownException = @"FBElementAttributeUnknownException";