Handle iOS Universal Links

shell/platform/darwin/ios/framework/Source/FlutterAppDelegate.mm

@@ -227,9 +227,43 @@ - (BOOL)application:(UIApplication*)application
     continueUserActivity:(NSUserActivity*)userActivity
       restorationHandler:(void (^)(NSArray* __nullable restorableObjects))restorationHandler {
 #endif
-  return [_lifeCycleDelegate application:application
-                    continueUserActivity:userActivity
-                      restorationHandler:restorationHandler];
+  if ([_lifeCycleDelegate application:application
+                 continueUserActivity:userActivity
+                   restorationHandler:restorationHandler]) {
+    return YES;
+  } else if (userActivity.activityType == NSUserActivityTypeBrowsingWeb) {
+    return NO;
+  } else {
+    NSURLComponents* components = [NSURLComponents componentsWithURL:userActivity.webpageURL
+                                             resolvingAgainstBaseURL:YES];
+
+    if (components == nil or components.path == nil) {
+      return NO;
+    }
+    FlutterViewController* flutterViewController = [self rootFlutterViewController];
+    if (flutterViewController) {
+      [flutterViewController.engine
+          waitForFirstFrame:3.0
+                   callback:^(BOOL didTimeout) {
+                     if (didTimeout) {
+                       FML_LOG(ERROR) << "Timeout waiting for the first frame when launching a "
+                                         "universal link.";
+                     } else {
+                       NSString* pathAndQuery = components.path;
+                       if (components.query != nil and [components.query length] != 0) {
+                         pathAndQuery =
+                             [NSString stringWithFormat:@"%@?%@", pathAndQuery, components.query];
+                       }
+                       [flutterViewController.engine.navigationChannel invokeMethod:@"pushRoute"
+                                                                          arguments:pathAndQuery];
+                     }
+                   }];
+      return YES;
+    } else {
+      FML_LOG(ERROR) << "Attempting to open a universal link without a Flutter RootViewController.";
+      return NO;
+    }
+  }
 }
 
 #pragma mark - FlutterPluginRegistry methods. All delegating to the rootViewController

shell/platform/darwin/ios/framework/Source/FlutterAppDelegateTest.mm

@@ -42,4 +42,28 @@ - (void)skip_testLaunchUrl {
   OCMVerify([navigationChannel invokeMethod:@"pushRoute" arguments:@"/custom/route?query=test"]);
 }
 
+- (void)skip_testLaunchUniversalLink {
+  FlutterAppDelegate* appDelegate = [[FlutterAppDelegate alloc] init];
+  FlutterViewController* viewController = OCMClassMock([FlutterViewController class]);
+  FlutterEngine* engine = OCMClassMock([FlutterEngine class]);
+  FlutterMethodChannel* navigationChannel = OCMClassMock([FlutterMethodChannel class]);
+  OCMStub([engine navigationChannel]).andReturn(navigationChannel);
+  OCMStub([viewController engine]).andReturn(engine);
+  OCMStub([engine waitForFirstFrame:3.0 callback:([OCMArg invokeBlockWithArgs:@(NO), nil])]);
+  appDelegate.rootFlutterViewControllerGetter = ^{
+    return viewController;
+  };
+  NSURL* url = [NSURL URLWithString:@"http://myApp/custom/route?query=test"];
+  NSUserActivity* userActivity =
+      [[NSUserActivity alloc] initWithActivityType:NSUserActivityTypeBrowsingWeb];
+  userActivity.webpageURL = url;
+  BOOL result = [appDelegate
+               application:[UIApplication sharedApplication]
+      continueUserActivity:userActivity
+        restorationHandler:^(NSArray<id<UIUserActivityRestoring>>* __nullable restorableObjects){
+        }];
+  XCTAssertTrue(result);
+  OCMVerify([navigationChannel invokeMethod:@"pushRoute" arguments:@"/custom/route?query=test"]);
+}
+
 @end