Add ios platform view integration test (#51882)

dev/devicelab/bin/tasks/ios_platform_view_tests.dart

+// Copyright 2014 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:async';
+
+import 'package:flutter_devicelab/framework/adb.dart';
+import 'package:flutter_devicelab/framework/framework.dart';
+import 'package:flutter_devicelab/tasks/integration_tests.dart';
+
+Future<void> main() async {
+  deviceOperatingSystem = DeviceOperatingSystem.ios;
+  await task(createIOSPlatformViewTests());
+}

dev/devicelab/lib/tasks/integration_tests.dart

@@ -122,6 +122,13 @@ TaskFunction createFlutterDriverScreenshotTest({
   );
 }
 
+TaskFunction createIOSPlatformViewTests() {
+  return DriverTest(
+    '${flutterDirectory.path}/dev/integration_tests/ios_platform_view_tests',
+    'lib/main.dart',
+  );
+}
+
 class DriverTest {
   DriverTest(
     this.testDirectory,

dev/devicelab/manifest.yaml

@@ -564,6 +564,12 @@ tasks:
     # Remove the flaky flag when we are sure the test is stable.
     flaky: true
 
+  ios_platform_view_tests:
+    description: >
+      Runs end-to-end tests with platform views in the scene.
+    stage: devicelab_ios
+    required_agent_capabilities: ["mac/ios"]
+
   # TODO(fujino): does not pass on iOS13 https://github.com/flutter/flutter/issues/41133
   # system_debug_ios:
   #   description: >

dev/integration_tests/ios_platform_view_tests/.metadata

+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: a2d0d0a2be50ec0aa728f552ba4ffa6296ab2898
+  channel: screenshot_test
+
+project_type: app

dev/integration_tests/ios_platform_view_tests/README.md

+# ios_platform_view_test
+
+A simple app contains:
+
+* A home with with a button that pushes a new page into the scene.
+* A page contains a platform view, a button and a text.
+    * Press the button will update the text.
+
+We use this app to test platform views in general such as platform view creation, destruction and thread merging(iOS only).

dev/integration_tests/ios_platform_view_tests/ios/.gitignore

+*.mode1v3
+*.mode2v3
+*.moved-aside
+*.pbxuser
+*.perspectivev3
+**/*sync/
+.sconsign.dblite
+.tags*
+**/.vagrant/
+**/DerivedData/
+Icon?
+**/Pods/
+**/.symlinks/
+profile
+xcuserdata
+**/.generated/
+Flutter/App.framework
+Flutter/Flutter.framework
+Flutter/Flutter.podspec
+Flutter/Generated.xcconfig
+Flutter/app.flx
+Flutter/app.zip
+Flutter/flutter_assets/
+Flutter/flutter_export_environment.sh
+ServiceDefinitions.json
+Runner/GeneratedPluginRegistrant.*
+
+# Exceptions to above rules.
+!default.mode1v3
+!default.mode2v3
+!default.pbxuser
+!default.perspectivev3

dev/integration_tests/ios_platform_view_tests/ios/Flutter/AppFrameworkInfo.plist

+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+  <key>CFBundleDevelopmentRegion</key>
+  <string>$(DEVELOPMENT_LANGUAGE)</string>
+  <key>CFBundleExecutable</key>
+  <string>App</string>
+  <key>CFBundleIdentifier</key>
+  <string>io.flutter.flutter.app</string>
+  <key>CFBundleInfoDictionaryVersion</key>
+  <string>6.0</string>
+  <key>CFBundleName</key>
+  <string>App</string>
+  <key>CFBundlePackageType</key>
+  <string>FMWK</string>
+  <key>CFBundleShortVersionString</key>
+  <string>1.0</string>
+  <key>CFBundleSignature</key>
+  <string>????</string>
+  <key>CFBundleVersion</key>
+  <string>1.0</string>
+  <key>MinimumOSVersion</key>
+  <string>8.0</string>
+</dict>
+</plist>

dev/integration_tests/ios_platform_view_tests/ios/Flutter/Debug.xcconfig

+#include "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
+#include "Generated.xcconfig"

dev/integration_tests/ios_platform_view_tests/ios/Flutter/Release.xcconfig

+#include "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
+#include "Generated.xcconfig"

dev/integration_tests/ios_platform_view_tests/ios/Podfile

+# Uncomment this line to define a global platform for your project
+# platform :ios, '9.0'
+
+# CocoaPods analytics sends network stats synchronously affecting flutter build latency.
+ENV['COCOAPODS_DISABLE_STATS'] = 'true'
+
+project 'Runner', {
+  'Debug' => :debug,
+  'Profile' => :release,
+  'Release' => :release,
+}
+
+def parse_KV_file(file, separator='=')
+  file_abs_path = File.expand_path(file)
+  if !File.exists? file_abs_path
+    return [];
+  end
+  generated_key_values = {}
+  skip_line_start_symbols = ["#", "/"]
+  File.foreach(file_abs_path) do |line|
+    next if skip_line_start_symbols.any? { |symbol| line =~ /^\s*#{symbol}/ }
+    plugin = line.split(pattern=separator)
+    if plugin.length == 2
+      podname = plugin[0].strip()
+      path = plugin[1].strip()
+      podpath = File.expand_path("#{path}", file_abs_path)
+      generated_key_values[podname] = podpath
+    else
+      puts "Invalid plugin specification: #{line}"
+    end
+  end
+  generated_key_values
+end
+
+target 'Runner' do
+  # Flutter Pod
+
+  copied_flutter_dir = File.join(__dir__, 'Flutter')
+  copied_framework_path = File.join(copied_flutter_dir, 'Flutter.framework')
+  copied_podspec_path = File.join(copied_flutter_dir, 'Flutter.podspec')
+  unless File.exist?(copied_framework_path) && File.exist?(copied_podspec_path)
+    # Copy Flutter.framework and Flutter.podspec to Flutter/ to have something to link against if the xcode backend script has not run yet.
+    # That script will copy the correct debug/profile/release version of the framework based on the currently selected Xcode configuration.
+    # CocoaPods will not embed the framework on pod install (before any build phases can generate) if the dylib does not exist.
+
+    generated_xcode_build_settings_path = File.join(copied_flutter_dir, 'Generated.xcconfig')
+    unless File.exist?(generated_xcode_build_settings_path)
+      raise "Generated.xcconfig must exist. If you're running pod install manually, make sure flutter pub get is executed first"
+    end
+    generated_xcode_build_settings = parse_KV_file(generated_xcode_build_settings_path)
+    cached_framework_dir = generated_xcode_build_settings['FLUTTER_FRAMEWORK_DIR'];
+
+    unless File.exist?(copied_framework_path)
+      FileUtils.cp_r(File.join(cached_framework_dir, 'Flutter.framework'), copied_flutter_dir)
+    end
+    unless File.exist?(copied_podspec_path)
+      FileUtils.cp(File.join(cached_framework_dir, 'Flutter.podspec'), copied_flutter_dir)
+    end
+  end
+
+  # Keep pod path relative so it can be checked into Podfile.lock.
+  pod 'Flutter', :path => 'Flutter'
+
+  # Plugin Pods
+
+  # Prepare symlinks folder. We use symlinks to avoid having Podfile.lock
+  # referring to absolute paths on developers' machines.
+  system('rm -rf .symlinks')
+  system('mkdir -p .symlinks/plugins')
+  plugin_pods = parse_KV_file('../.flutter-plugins')
+  plugin_pods.each do |name, path|
+    symlink = File.join('.symlinks', 'plugins', name)
+    File.symlink(path, symlink)
+    pod name, :path => File.join(symlink, 'ios')
+  end
+end
+
+# Prevent Cocoapods from embedding a second Flutter framework and causing an error with the new Xcode build system.
+install! 'cocoapods', :disable_input_output_paths => true
+
+post_install do |installer|
+  installer.pods_project.targets.each do |target|
+    target.build_configurations.each do |config|
+      config.build_settings['ENABLE_BITCODE'] = 'NO'
+    end
+  end
+end

dev/integration_tests/ios_platform_view_tests/ios/Runner.xcodeproj/project.xcworkspace/contents.xcworkspacedata

+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "group:Runner.xcodeproj">
+   </FileRef>
+</Workspace>

dev/integration_tests/ios_platform_view_tests/ios/Runner.xcworkspace/contents.xcworkspacedata

+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "group:Runner.xcodeproj">
+   </FileRef>
+   <FileRef
+      location = "group:Pods/Pods.xcodeproj">
+   </FileRef>
+</Workspace>

dev/integration_tests/ios_platform_view_tests/ios/Runner/AppDelegate.h

+// Copyright 2014 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 <UIKit/UIKit.h>
+
+@interface AppDelegate : FlutterAppDelegate
+
+@end

dev/integration_tests/ios_platform_view_tests/ios/Runner/AppDelegate.m

+// Copyright 2014 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 "AppDelegate.h"
+#import "GeneratedPluginRegistrant.h"
+
+@interface PlatformView: NSObject<FlutterPlatformView>
+
+@property (strong, nonatomic) UIView *platformView;
+
+@end
+
+@implementation PlatformView
+
+- (instancetype)init
+{
+  self = [super init];
+  if (self) {
+    self.platformView = [[UIView alloc] init];
+    self.platformView.backgroundColor = [UIColor blueColor];
+  }
+  return self;
+}
+
+- (UIView *)view {
+  return self.platformView;
+}
+
+@end
+
+@interface ViewFactory: NSObject<FlutterPlatformViewFactory>
+
+@end
+
+@implementation ViewFactory
+
+- (NSObject<FlutterPlatformView> *)createWithFrame:(CGRect)frame viewIdentifier:(int64_t)viewId arguments:(id)args {
+  PlatformView *platformView = [[PlatformView alloc] init];
+  return platformView;
+}
+
+@end
+
+@implementation AppDelegate
+
+- (BOOL)application:(UIApplication *)application
+    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
+  [GeneratedPluginRegistrant registerWithRegistry:self];
+  // Override point for customization after application launch.
+  [[self registrarForPlugin:@"flutter"] registerViewFactory:[ViewFactory new] withId:@"platform_view"];
+  return [super application:application didFinishLaunchingWithOptions:launchOptions];
+}
+
+@end

dev/integration_tests/ios_platform_view_tests/ios/Runner/Assets.xcassets/AppIcon.appiconset/Contents.json

+{
+  "images" : [
+    {
+      "size" : "20x20",
+      "idiom" : "iphone",
+      "filename" : "Icon-App-20x20@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "20x20",
+      "idiom" : "iphone",
+      "filename" : "Icon-App-20x20@3x.png",
+      "scale" : "3x"
+    },
+    {
+      "size" : "29x29",
+      "idiom" : "iphone",
+      "filename" : "Icon-App-29x29@1x.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "29x29",
+      "idiom" : "iphone",
+      "filename" : "Icon-App-29x29@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "29x29",
+      "idiom" : "iphone",
+      "filename" : "Icon-App-29x29@3x.png",
+      "scale" : "3x"
+    },
+    {
+      "size" : "40x40",
+      "idiom" : "iphone",
+      "filename" : "Icon-App-40x40@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "40x40",
+      "idiom" : "iphone",
+      "filename" : "Icon-App-40x40@3x.png",
+      "scale" : "3x"
+    },
+    {
+      "size" : "60x60",
+      "idiom" : "iphone",
+      "filename" : "Icon-App-60x60@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "60x60",
+      "idiom" : "iphone",
+      "filename" : "Icon-App-60x60@3x.png",
+      "scale" : "3x"
+    },
+    {
+      "size" : "20x20",
+      "idiom" : "ipad",
+      "filename" : "Icon-App-20x20@1x.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "20x20",
+      "idiom" : "ipad",
+      "filename" : "Icon-App-20x20@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "29x29",
+      "idiom" : "ipad",
+      "filename" : "Icon-App-29x29@1x.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "29x29",
+      "idiom" : "ipad",
+      "filename" : "Icon-App-29x29@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "40x40",
+      "idiom" : "ipad",
+      "filename" : "Icon-App-40x40@1x.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "40x40",
+      "idiom" : "ipad",
+      "filename" : "Icon-App-40x40@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "76x76",
+      "idiom" : "ipad",
+      "filename" : "Icon-App-76x76@1x.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "76x76",
+      "idiom" : "ipad",
+      "filename" : "Icon-App-76x76@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "83.5x83.5",
+      "idiom" : "ipad",
+      "filename" : "Icon-App-83.5x83.5@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "1024x1024",
+      "idiom" : "ios-marketing",
+      "filename" : "Icon-App-1024x1024@1x.png",
+      "scale" : "1x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

dev/integration_tests/ios_platform_view_tests/ios/Runner/Assets.xcassets/LaunchImage.imageset/Contents.json

+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "LaunchImage.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "LaunchImage@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "LaunchImage@3x.png",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

dev/integration_tests/ios_platform_view_tests/ios/Runner/Assets.xcassets/LaunchImage.imageset/README.md

+# Launch Screen Assets
+
+You can customize the launch screen with your own desired assets by replacing the image files in this directory.
+
+You can also do it by opening your Flutter project's Xcode project with `open ios/Runner.xcworkspace`, selecting `Runner/Assets.xcassets` in the Project Navigator and dropping in the desired images.
\ No newline at end of file

dev/integration_tests/ios_platform_view_tests/ios/Runner/Base.lproj/LaunchScreen.storyboard

+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="12121" systemVersion="16G29" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" colorMatched="YES" initialViewController="01J-lp-oVM">
+    <dependencies>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="12089"/>
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="EHf-IW-A2E">
+            <objects>
+                <viewController id="01J-lp-oVM" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="Ydg-fD-yQy"/>
+                        <viewControllerLayoutGuide type="bottom" id="xbc-2k-c8Z"/>
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="Ze5-6b-2t3">
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <subviews>
+                            <imageView opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" image="LaunchImage" translatesAutoresizingMaskIntoConstraints="NO" id="YRO-k0-Ey4">
+                            </imageView>
+                        </subviews>
+                        <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                        <constraints>
+                            <constraint firstItem="YRO-k0-Ey4" firstAttribute="centerX" secondItem="Ze5-6b-2t3" secondAttribute="centerX" id="1a2-6s-vTC"/>
+                            <constraint firstItem="YRO-k0-Ey4" firstAttribute="centerY" secondItem="Ze5-6b-2t3" secondAttribute="centerY" id="4X2-HB-R7a"/>
+                        </constraints>
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="iYj-Kq-Ea1" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="53" y="375"/>
+        </scene>
+    </scenes>
+    <resources>
+        <image name="LaunchImage" width="168" height="185"/>
+    </resources>
+</document>

dev/integration_tests/ios_platform_view_tests/ios/Runner/Base.lproj/Main.storyboard

+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="10117" systemVersion="15F34" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" initialViewController="BYZ-38-t0r">
+    <dependencies>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="10085"/>
+    </dependencies>
+    <scenes>
+        <!--Flutter View Controller-->
+        <scene sceneID="tne-QT-ifu">
+            <objects>
+                <viewController id="BYZ-38-t0r" customClass="FlutterViewController" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="y3c-jy-aDJ"/>
+                        <viewControllerLayoutGuide type="bottom" id="wfy-db-euE"/>
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="8bC-Xf-vdC">
+                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="dkx-z0-nzr" sceneMemberID="firstResponder"/>
+            </objects>
+        </scene>
+    </scenes>
+</document>

dev/integration_tests/ios_platform_view_tests/ios/Runner/Info.plist

+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>$(DEVELOPMENT_LANGUAGE)</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>platform_view_test</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>$(FLUTTER_BUILD_NAME)</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleVersion</key>
+	<string>$(FLUTTER_BUILD_NUMBER)</string>
+	<key>LSRequiresIPhoneOS</key>
+	<true/>
+	<key>UILaunchStoryboardName</key>
+	<string>LaunchScreen</string>
+	<key>UIMainStoryboardFile</key>
+	<string>Main</string>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+	<key>UISupportedInterfaceOrientations~ipad</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationPortraitUpsideDown</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+	<key>UIViewControllerBasedStatusBarAppearance</key>
+	<false/>
+	<key>io.flutter.embedded_views_preview</key>
+	<true/>
+</dict>
+</plist>

dev/integration_tests/ios_platform_view_tests/ios/Runner/main.m

+// Copyright 2014 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 <UIKit/UIKit.h>
+#import "AppDelegate.h"
+
+int main(int argc, char* argv[]) {
+  @autoreleasepool {
+    return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
+  }
+}

dev/integration_tests/ios_platform_view_tests/lib/main.dart

+// Copyright 2014 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 'package:flutter/material.dart';
+import 'package:flutter_driver/driver_extension.dart';
+
+void main() {
+  enableFlutterDriverExtension();
+  runApp(MyApp());
+}
+
+/// The main app entrance of the test
+class MyApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Flutter Demo',
+      theme: ThemeData(
+        primarySwatch: Colors.blue,
+      ),
+      home: const MyHomePage(title: 'Flutter Demo Home Page'),
+    );
+  }
+}
+
+/// A page with a button in the center.
+///
+/// On press the button, a page with platform view should be pushed into the scene.
+class MyHomePage extends StatefulWidget {
+  const MyHomePage({Key key, this.title}) : super(key: key);
+  final String title;
+
+  @override
+  _MyHomePageState createState() => _MyHomePageState();
+}
+
+class _MyHomePageState extends State<MyHomePage> {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(widget.title),
+      ),
+      body: Column(children: <Widget>[
+        FlatButton(
+          key: const ValueKey<String>('platform_view_button'),
+          child: const Text('show platform view'),
+          onPressed: () {
+            Navigator.push(
+              context,
+              MaterialPageRoute<PlatformViewPage>(
+                  builder: (BuildContext context) => PlatformViewPage()),
+            );
+          },
+        ),
+        // Push this button to perform an animation, which ensure the threads are unmerged after the animation.
+        RaisedButton(
+          key: const ValueKey<String>('unmerge_button'),
+          child: const Text('Tap to unmerge threads'),
+          onPressed: () {},
+        ),
+      ]),
+    );
+  }
+}
+
+/// A page contains the platform view to be tested.
+class PlatformViewPage extends StatelessWidget {
+  final Key button = const ValueKey<String>('plus_button');
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('Platform View'),
+      ),
+      body: Column(
+        children: <Widget>[
+          Container(
+            child: const UiKitView(viewType: 'platform_view'),
+            width: 300,
+            height: 300,
+          ),
+          RaisedButton(
+            key: button,
+            child: const Text('button'),
+            onPressed: (){},
+          )
+        ],
+      ),
+    );
+  }
+}

dev/integration_tests/ios_platform_view_tests/pubspec.yaml

+name: ios_platform_view_tests
+
+version: 1.0.0+1
+environment:
+  sdk: ">=2.1.0 <3.0.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+
+  collection: 1.14.11 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  meta: 1.1.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  vector_math: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  flutter_driver:
+    sdk: flutter
+  e2e: 0.3.0
+  test: 1.14.2
+
+  _fe_analyzer_shared: 1.0.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  analyzer: 0.39.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  archive: 2.0.11 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  args: 1.5.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  async: 2.4.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  boolean_selector: 1.0.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  charcode: 1.1.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  convert: 2.1.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  coverage: 0.13.9 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  crypto: 2.1.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  csslib: 0.16.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  file: 5.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  glob: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  html: 0.14.0+3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  http: 0.12.0+4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  http_multi_server: 2.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  http_parser: 3.1.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  image: 2.1.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  intl: 0.16.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  io: 0.3.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  js: 0.6.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  json_rpc_2: 2.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  logging: 0.11.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  matcher: 0.12.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  mime: 0.9.6+3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  multi_server_socket: 1.0.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  node_interop: 1.0.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  node_io: 1.0.1+2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  node_preamble: 1.4.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  package_config: 1.9.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  package_resolver: 1.0.10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  path: 1.6.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pedantic: 1.9.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  petitparser: 2.4.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pool: 1.4.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pub_semver: 1.4.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  quiver: 2.0.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf: 0.7.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_packages_handler: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_static: 0.2.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_web_socket: 0.2.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  source_map_stack_trace: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  source_maps: 0.10.9 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  source_span: 1.5.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  stack_trace: 1.9.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  stream_channel: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  string_scanner: 1.0.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  sync_http: 0.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_api: 0.2.15 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.3.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  vm_service: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  vm_service_client: 0.2.6+2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  watcher: 0.9.7+14 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  web_socket_channel: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  webdriver: 2.1.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  webkit_inspection_protocol: 0.5.0+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  xml: 3.5.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  yaml: 2.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+
+flutter:
+
+  uses-material-design: true
+
+# PUBSPEC CHECKSUM: 93e6

dev/integration_tests/ios_platform_view_tests/test_driver/main_test.dart

+// Copyright 2014 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:async';
+import 'dart:io';
+import 'package:flutter_driver/flutter_driver.dart';
+import 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
+
+// TODO(cyanglaz): Move the test to engine repo once https://github.com/flutter/flutter/issues/51892 is resolved.
+Future<void> main() async {
+  FlutterDriver driver;
+
+  setUpAll(() async {
+    driver = await FlutterDriver.connect();
+  });
+
+  tearDownAll(() => driver.close());
+
+  test('Merge thread to create and remove platform views should not crash', () async {
+
+    // Start pushing in a page with platform view, merge threads.
+    final SerializableFinder platformViewButton =
+        find.byValueKey('platform_view_button');
+    await driver.waitFor(platformViewButton);
+    await driver.tap(platformViewButton);
+
+    // Wait for the platform view page to show.
+    final SerializableFinder plusButton =
+        find.byValueKey('plus_button');
+    await driver.waitFor(plusButton);
+    await driver.waitUntilNoTransientCallbacks();
+
+    // Tapping a raised button runs an animation that pumps enough frames to un-merge the threads.
+    await driver.tap(plusButton);
+    await driver.waitUntilNoTransientCallbacks();
+
+    // Remove the page with platform view, merge threads again.
+    final SerializableFinder backButton = find.pageBack();
+    await driver.tap(backButton);
+    await driver.waitUntilNoTransientCallbacks();
+
+    final Health driverHealth = await driver.checkHealth();
+    expect(driverHealth.status, HealthStatus.ok);
+  }, skip: !Platform.isIOS);
+
+    test('Merge thread to create and remove platform views should not crash', () async {
+
+    // Start pushing in a page with platform view, merge threads.
+    final SerializableFinder platformViewButton =
+        find.byValueKey('platform_view_button');
+    await driver.waitFor(platformViewButton);
+    await driver.tap(platformViewButton);
+    await driver.waitUntilNoTransientCallbacks();
+
+    // Remove the page with platform view, threads are still merged.
+    final SerializableFinder backButton = find.pageBack();
+    await driver.tap(backButton);
+    await driver.waitUntilNoTransientCallbacks();
+
+    // The animation of tapping a `RaisedButton` should pump enough frames to un-merge the thread.
+    final SerializableFinder unmergeButton =
+        find.byValueKey('unmerge_button');
+    await driver.waitFor(unmergeButton);
+    await driver.tap(unmergeButton);
+    await driver.waitUntilNoTransientCallbacks();
+
+    final Health driverHealth = await driver.checkHealth();
+    expect(driverHealth.status, HealthStatus.ok);
+  }, skip: !Platform.isIOS);
+}

dev/integration_tests/ios_platform_view_tests/test_driver/platform_view_e2e.dart

+// Copyright 2014 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:io';
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:e2e/e2e.dart';
+
+// TODO(cyanglaz): e2e test is not current running on flutter/flutter.
+// Move the e2e test to engine repo once https://github.com/flutter/flutter/issues/51892 is resolved.
+void main() {
+  E2EWidgetsFlutterBinding.ensureInitialized();
+
+  testWidgets('merging thread to remove platform views does not crash',
+      (WidgetTester tester) async {
+    // Pump a frame with platform view, threads are merged.
+    await tester.pumpWidget(Directionality(
+      textDirection: TextDirection.ltr,
+      child: Container(
+        child: const UiKitView(viewType: 'platform_view'),
+        width: 300,
+        height: 300,
+      ),
+    ));
+
+    // Pump enough widgets to un-merge the threads.
+    for (int i = 0; i < 100; i++) {
+      await tester.pump();
+    }
+    // Remove platform view, thread should be merged during this frame.
+    await tester.pumpWidget(Directionality(
+      textDirection: TextDirection.ltr,
+      child: Container(),
+    ));
+  }, skip: !Platform.isIOS);
+
+  testWidgets('un-merging thread after removing the platform view does not crash',
+      (WidgetTester tester) async {
+    // Pump a frame with platform view, threads are merged.
+    await tester.pumpWidget(Directionality(
+      textDirection: TextDirection.ltr,
+      child: Container(
+        child: const UiKitView(viewType: 'platform_view'),
+        width: 300,
+        height: 300,
+      ),
+    ));
+
+    // Remove platform view, thread should still be merged at this moment as the lease hasn't expired.
+    await tester.pumpWidget(Directionality(
+      textDirection: TextDirection.ltr,
+      child: Container(),
+    ));
+
+    // Pump enough widgets to un-merge the threads.
+    for (int i = 0; i < 100; i++) {
+      await tester.pump();
+    }
+  }, skip: !Platform.isIOS);
+}

dev/integration_tests/ios_platform_view_tests/test_driver/platform_view_e2e_test.dart

+// Copyright 2014 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:async';
+import 'dart:io';
+import 'package:flutter_driver/flutter_driver.dart';
+
+Future<void> main() async {
+  final FlutterDriver driver = await FlutterDriver.connect();
+  final String result =
+      await driver.requestData(null, timeout: const Duration(minutes: 1));
+  await driver.close();
+  exit(result == 'pass' ? 0 : 1);
+}