add test

Author: GaryQian

testing/scenario_app/ios/Scenarios/ScenariosTests/LocalizationInitializationTest.m

@@ -0,0 +1,62 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <Flutter/Flutter.h>
+#import <XCTest/XCTest.h>
+#import "AppDelegate.h"
+
+@interface XCUIElement (ftr_waitForNonExistence)
+/// Keeps waiting until the element doesn't exist.  Returns NO if the timeout is
+/// reached before it doesn't exist.
+- (BOOL)ftr_waitForNonExistenceWithTimeout:(NSTimeInterval)timeout;
+/// Waits the full duration to ensure something doesn't exist for that duration.
+/// Returns NO if at some point the element exists during the duration.
+- (BOOL)ftr_waitForNonExistenceForDuration:(NSTimeInterval)duration;
+@end
+
+@implementation XCUIElement (ftr_waitForNonExistence)
+- (BOOL)ftr_waitForNonExistenceWithTimeout:(NSTimeInterval)timeout {
+  NSTimeInterval delta = 0.5;
+  while (timeout > 0.0) {
+    if (!self.exists) {
+      return YES;
+    }
+    usleep(delta * 1000000);
+    timeout -= delta;
+  }
+  return NO;
+}
+
+- (BOOL)ftr_waitForNonExistenceForDuration:(NSTimeInterval)duration {
+  return ![self waitForExistenceWithTimeout:duration];
+}
+
+@end
+
+@interface LocalizationInitializationTest : XCTestCase
+@property(nonatomic, strong) XCUIApplication* application;
+@end
+
+@implementation LocalizationInitializationTest
+
+- (void)setUp {
+  [super setUp];
+  self.continueAfterFailure = NO;
+
+  self.application = [[XCUIApplication alloc] init];
+  self.application.launchArguments = @[ @"--locale-initialization" ];
+  [self.application launch];
+}
+
+- (void)testNoLocalePrepend {
+  NSTimeInterval timeout = 10.0;
+
+  // The locales recieved by dart:ui are exposed onBeginFrame via semantics label.
+  // There should only be one locale, as we have removed the locale prepend on iOS.
+  XCUIElement* textInputSemanticsObject =
+      [[[self.application textFields] matchingIdentifier:@"[en_US]"] element];
+  XCTAssertTrue([textInputSemanticsObject waitForExistenceWithTimeout:timeout]);
+}
+
+@end

testing/scenario_app/lib/src/locale_initialization.dart

@@ -0,0 +1,66 @@
+// Copyright 2020 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:typed_data';
+import 'dart:ui';
+
+import 'scenario.dart';
+
+/// A scenario that sends back messages when touches are received.
+class LocaleInitialization extends Scenario {
+  /// Constructor for `SendTextFocusScemantics`.
+  LocaleInitialization(Window window)
+      : assert(window != null),
+        super(window);
+
+  @override
+  void onBeginFrame(Duration duration) {
+    // Doesn't matter what we draw. Just paint white.
+    final SceneBuilder builder = SceneBuilder();
+    final PictureRecorder recorder = PictureRecorder();
+    final Canvas canvas = Canvas(recorder);
+
+    canvas.drawRect(
+      Rect.fromLTWH(0, 0, window.physicalSize.width, window.physicalSize.height),
+      Paint()..color = const Color.fromARGB(255, 255, 255, 255),
+    );
+    final Picture picture = recorder.endRecording();
+
+    builder.addPicture(
+      Offset.zero,
+      picture,
+    );
+    final Scene scene = builder.build();
+    window.render(scene);
+    scene.dispose();
+
+    // On the first frame, also pretend that it drew a text field. Send the
+    // corresponding semantics tree comprised of 1 node for the text field.
+    window.updateSemantics((SemanticsUpdateBuilder()
+      ..updateNode(
+        id: 0,
+        // SemanticsFlag.isTextField.
+        flags: 16,
+        // SemanticsAction.tap.
+        actions: 1,
+        rect: const Rect.fromLTRB(0.0, 0.0, 414.0, 48.0),
+        label: window.locales.toString(),
+        textDirection: TextDirection.ltr,
+        textSelectionBase: -1,
+        textSelectionExtent: -1,
+        platformViewId: -1,
+        maxValueLength: -1,
+        currentValueLength: 0,
+        scrollChildren: 0,
+        scrollIndex: 0,
+        // transform: Matrix4.identity().storage,
+        elevation: 0.0,
+        thickness: 0.0,
+        childrenInTraversalOrder: Int32List(0),
+        childrenInHitTestOrder: Int32List(0),
+        additionalActions: Int32List(0),
+      )).build()
+    );
+  }
+}

testing/scenario_app/lib/src/scenarios.dart

@@ -6,6 +6,7 @@
 import 'dart:ui';
 
 import 'animated_color_square.dart';
+import 'src/locale_initialization.dart';
 import 'platform_view.dart';
 import 'poppable_screen.dart';
 import 'scenario.dart';
@@ -14,6 +15,7 @@ import 'touches_scenario.dart';
 
 Map<String, Scenario> _scenarios = <String, Scenario>{
   'animated_color_square': AnimatedColorSquareScenario(window),
+  'locale_initialization': LocaleInitialization(window),
   'platform_view': PlatformViewScenario(window, 'Hello from Scenarios (Platform View)', id: 0),
   'platform_view_no_overlay_intersection': PlatformViewNoOverlayIntersectionScenario(window, 'Hello from Scenarios (Platform View)', id: 0),
   'platform_view_partial_intersection': PlatformViewPartialIntersectionScenario(window, 'Hello from Scenarios (Platform View)', id: 0),