Move context menus out of experimental (#2134)

Now that the context menu code is on stable, move the sample out of
experimental.

Fixes https://github.com/flutter/samples/issues/2110

## Pre-launch Checklist

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] All existing and new tests are passing.

---------

Co-authored-by: Brett Morgan <brett.morgan@gmail.com>

context_menus/test/anywhere_page_test.dart

@@ -0,0 +1,36 @@
+import 'package:context_menus/anywhere_page.dart';
+import 'package:context_menus/main.dart';
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Right click works outside of text', (tester) async {
+    await tester.pumpWidget(const MyApp());
+
+    // Navigate to the AnywherePage example.
+    await tester.dragUntilVisible(
+      find.text(AnywherePage.title),
+      find.byType(ListView),
+      const Offset(0.0, -100.0),
+    );
+    await tester.pumpAndSettle();
+    await tester.tap(find.text(AnywherePage.title));
+    await tester.pumpAndSettle();
+
+    // Right click on the background of the app to show the context menu.
+    final TestGesture gesture = await tester.startGesture(
+      const Offset(100.0, 100.0),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture.up();
+    await gesture.removePointer();
+    await tester.pumpAndSettle();
+
+    // The context menu is shown, with a custom back button.
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
+    expect(find.text('Back'), findsOneWidget);
+  });
+}

context_menus/test/cascading_menu_page_test.dart

@@ -0,0 +1,126 @@
+import 'package:context_menus/cascading_menu_page.dart';
+import 'package:context_menus/main.dart';
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Can show and use the cascading menu', (tester) async {
+    await tester.pumpWidget(const MyApp());
+
+    // Navigate to the CascadingMenuPage example.
+    await tester.dragUntilVisible(
+      find.text(CascadingMenuPage.title),
+      find.byType(ListView),
+      const Offset(0.0, -250.0),
+    );
+    await tester.pumpAndSettle();
+    await tester.tap(find.text(CascadingMenuPage.title));
+    await tester.pumpAndSettle();
+
+    const String message =
+        'Right click or long press anywhere to show the cascading menu.';
+    expect(find.text(message), findsOneWidget);
+
+    // Right click on the background of the app to show the cascading context
+    // menu.
+    TestGesture gesture = await tester.startGesture(
+      const Offset(0.0, 100.0),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture.up();
+    await gesture.removePointer();
+    await tester.pumpAndSettle();
+
+    // The custom cascading context menu is shown.
+    expect(find.byType(DesktopTextSelectionToolbar), findsOneWidget);
+    expect(find.text('About'), findsOneWidget);
+    expect(find.text('Show'), findsNothing);
+    expect(find.text('Hide'), findsOneWidget);
+    expect(find.text('Reset'), findsOneWidget);
+    expect(find.text('Color'), findsOneWidget);
+
+    // Click "Hide Message" and the message and menu are hidden.
+    await tester.tap(find.text('Hide'));
+    await tester.pumpAndSettle();
+    expect(find.byType(DesktopTextSelectionToolbar), findsNothing);
+    expect(find.text(message), findsNothing);
+
+    // Right click to show the menu again.
+    gesture = await tester.startGesture(
+      const Offset(0.0, 100.0),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture.up();
+    await gesture.removePointer();
+    await tester.pumpAndSettle();
+    expect(find.byType(DesktopTextSelectionToolbar), findsOneWidget);
+    expect(find.text('About'), findsOneWidget);
+    expect(find.text('Show'), findsOneWidget);
+    expect(find.text('Hide'), findsNothing);
+    expect(find.text('Reset'), findsOneWidget);
+    expect(find.text('Color'), findsOneWidget);
+
+    // Use the shortcut to show the message again.
+    await tester.sendKeyDownEvent(LogicalKeyboardKey.control);
+    await tester.sendKeyDownEvent(LogicalKeyboardKey.keyS);
+    await tester.sendKeyUpEvent(LogicalKeyboardKey.control);
+    await tester.sendKeyUpEvent(LogicalKeyboardKey.keyS);
+    await tester.pumpAndSettle();
+    expect(find.byType(DesktopTextSelectionToolbar), findsNothing);
+    expect(find.text(message), findsOneWidget);
+
+    // Right click to show the menu again.
+    gesture = await tester.startGesture(
+      const Offset(0.0, 100.0),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture.up();
+    await gesture.removePointer();
+    await tester.pumpAndSettle();
+    expect(find.byType(DesktopTextSelectionToolbar), findsOneWidget);
+    expect(find.text('About'), findsOneWidget);
+    expect(find.text('Show'), findsNothing);
+    expect(find.text('Hide'), findsOneWidget);
+    expect(find.text('Reset'), findsOneWidget);
+    expect(find.text('Color'), findsOneWidget);
+    expect(find.text('Red'), findsNothing);
+    expect(find.text('Green'), findsNothing);
+    expect(find.text('Blue'), findsNothing);
+
+    // Hover Background Color.
+    gesture = await tester.startGesture(
+      //tester.getCenter(find.text('Color')),
+      const Offset(0.0, 100),
+      kind: PointerDeviceKind.mouse,
+    );
+    await tester.pump();
+    await gesture.moveTo(tester.getCenter(find.text('Color')));
+    await tester.pumpAndSettle();
+
+    // Background colors are shown.
+    expect(find.text('Red'), findsOneWidget);
+    expect(find.text('Green'), findsOneWidget);
+    expect(find.text('Blue'), findsOneWidget);
+
+    // Select green.
+    await gesture.moveTo(tester.getCenter(find.text('Green')));
+    await tester.pump();
+    await tester.tap(find.text('Green'));
+    await tester.pump();
+    await gesture.removePointer();
+
+    // The menu is gone and the UI shows green was selected.
+    expect(find.byType(DesktopTextSelectionToolbar), findsNothing);
+    expect(find.text('Last Selected: Green Background'), findsOneWidget);
+  },
+      // TODO(justinmc): https://github.com/flutter/samples/issues/2086
+      skip: true);
+}

context_menus/test/custom_buttons_page_test.dart

@@ -0,0 +1,55 @@
+import 'package:context_menus/custom_buttons_page.dart';
+import 'package:context_menus/main.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Shows custom buttons in the built-in context menu',
+      (tester) async {
+    await tester.pumpWidget(const MyApp());
+
+    // Navigate to the CustomButtonsPage example.
+    await tester.dragUntilVisible(
+      find.text(CustomButtonsPage.title),
+      find.byType(ListView),
+      const Offset(0.0, -100.0),
+    );
+    await tester.pumpAndSettle();
+    await tester.tap(find.text(CustomButtonsPage.title));
+    await tester.pumpAndSettle();
+
+    // Right click on the text field to show the context menu.
+    final TestGesture gesture = await tester.startGesture(
+      tester.getCenter(find.byType(EditableText)),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture.up();
+    await gesture.removePointer();
+    await tester.pumpAndSettle();
+
+    // The context menu is shown, and the buttons are custom widgets.
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
+    switch (defaultTargetPlatform) {
+      case TargetPlatform.iOS:
+        expect(find.byType(CupertinoTextSelectionToolbarButton), findsNothing);
+        expect(find.byType(CupertinoButton), findsNWidgets(2));
+      case TargetPlatform.macOS:
+        expect(find.byType(CupertinoButton), findsNWidgets(2));
+        expect(find.byType(CupertinoDesktopTextSelectionToolbarButton),
+            findsNothing);
+      case TargetPlatform.android:
+      case TargetPlatform.fuchsia:
+        expect(find.byType(CupertinoButton), findsNWidgets(1));
+        expect(find.byType(TextSelectionToolbarTextButton), findsNothing);
+      case TargetPlatform.linux:
+      case TargetPlatform.windows:
+        expect(find.byType(CupertinoButton), findsNWidgets(1));
+        expect(find.byType(DesktopTextSelectionToolbarButton), findsNothing);
+    }
+  });
+}

context_menus/test/custom_menu_page_test.dart

@@ -0,0 +1,53 @@
+import 'package:context_menus/custom_menu_page.dart';
+import 'package:context_menus/main.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Shows default buttons in a custom context menu', (tester) async {
+    await tester.pumpWidget(const MyApp());
+
+    // Navigate to the CustomMenuPage example.
+    await tester.dragUntilVisible(
+      find.text(CustomMenuPage.title),
+      find.byType(ListView),
+      const Offset(0.0, -200.0),
+    );
+    await tester.pumpAndSettle();
+    await tester.tap(find.text(CustomMenuPage.title));
+    await tester.pumpAndSettle();
+
+    // Right click on the text field to show the context menu.
+    final TestGesture gesture = await tester.startGesture(
+      tester.getCenter(find.byType(EditableText)),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture.up();
+    await gesture.removePointer();
+    await tester.pumpAndSettle();
+
+    // A custom context menu is shown, and the buttons are the default ones.
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);
+    expect(find.byType(CupertinoAdaptiveTextSelectionToolbar), findsNothing);
+    switch (defaultTargetPlatform) {
+      case TargetPlatform.iOS:
+        expect(
+            find.byType(CupertinoTextSelectionToolbarButton), findsNWidgets(2));
+      case TargetPlatform.macOS:
+        expect(find.byType(CupertinoDesktopTextSelectionToolbarButton),
+            findsNWidgets(2));
+      case TargetPlatform.android:
+      case TargetPlatform.fuchsia:
+        expect(find.byType(TextSelectionToolbarTextButton), findsNWidgets(1));
+      case TargetPlatform.linux:
+      case TargetPlatform.windows:
+        expect(
+            find.byType(DesktopTextSelectionToolbarButton), findsNWidgets(1));
+    }
+  });
+}

context_menus/test/default_values_page_test.dart

@@ -0,0 +1,99 @@
+import 'package:context_menus/default_values_page.dart';
+import 'package:context_menus/main.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Gives correct behavior for all values of contextMenuBuilder',
+      (tester) async {
+    await tester.pumpWidget(const MyApp());
+
+    // Navigate to the DefaultValuesPage example.
+    await tester.dragUntilVisible(
+      find.text(DefaultValuesPage.title),
+      find.byType(ListView),
+      const Offset(0.0, -100.0),
+    );
+    await tester.pumpAndSettle();
+    await tester.tap(find.text(DefaultValuesPage.title));
+    await tester.pumpAndSettle();
+    expect(
+      find.descendant(
+        of: find.byType(AppBar),
+        matching: find.text(DefaultValuesPage.title),
+      ),
+      findsOneWidget,
+    );
+
+    // Right click on the text field where contextMenuBuilder isn't passed.
+    TestGesture gesture = await tester.startGesture(
+      tester.getCenter(find.byType(EditableText).first),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture.up();
+    await gesture.removePointer();
+    await tester.pumpAndSettle();
+
+    // The default context menu is shown.
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
+    switch (defaultTargetPlatform) {
+      case TargetPlatform.iOS:
+        expect(
+            find.byType(CupertinoTextSelectionToolbarButton), findsNWidgets(2));
+      case TargetPlatform.macOS:
+        expect(find.byType(CupertinoDesktopTextSelectionToolbarButton),
+            findsNWidgets(2));
+      case TargetPlatform.android:
+      case TargetPlatform.fuchsia:
+        expect(find.byType(TextSelectionToolbarTextButton), findsNWidgets(1));
+      case TargetPlatform.linux:
+      case TargetPlatform.windows:
+        expect(
+            find.byType(DesktopTextSelectionToolbarButton), findsNWidgets(1));
+    }
+
+    // Tap the next field to hide the context menu.
+    await tester.tap(find.byType(EditableText).at(1));
+    await tester.pumpAndSettle();
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);
+
+    // Right click on the text field where contextMenuBuilder is given null.
+    gesture = await tester.startGesture(
+      tester.getCenter(find.byType(EditableText).at(1)),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture.up();
+    await gesture.removePointer();
+    await tester.pumpAndSettle();
+
+    // No context menu is shown.
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);
+
+    // Tap the next field to hide the context menu.
+    await tester.tap(find.byType(EditableText).at(2));
+    await tester.pumpAndSettle();
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);
+
+    // Right click on the text field with the custom contextMenuBuilder.
+    gesture = await tester.startGesture(
+      tester.getCenter(find.byType(EditableText).at(2)),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture.up();
+    await gesture.removePointer();
+    await tester.pumpAndSettle();
+
+    // The custom context menu is shown.
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
+    expect(find.text('Custom button'), findsOneWidget);
+  });
+}

context_menus/test/email_button_page_test.dart

@@ -0,0 +1,111 @@
+import 'package:context_menus/email_button_page.dart';
+import 'package:context_menus/main.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'utils.dart';
+
+void main() {
+  testWidgets('Selecting the email address shows a custom button',
+      (tester) async {
+    await tester.pumpWidget(const MyApp());
+
+    // Navigate to the EmailButtonPage example.
+    await tester.dragUntilVisible(
+      find.text(EmailButtonPage.title),
+      find.byType(ListView),
+      const Offset(0.0, -100.0),
+    );
+    await tester.pumpAndSettle();
+    await tester.tap(find.text(EmailButtonPage.title));
+    await tester.pumpAndSettle();
+
+    // Select the first word, then right click to show the context menu.
+    expect(find.byType(TextField), findsOneWidget);
+    await tester.tapAt(tester.getTopLeft(find.byType(EditableText)));
+    await tester.pumpAndSettle();
+    await tester.sendKeyDownEvent(LogicalKeyboardKey.shift);
+    for (int i = 0; i < 6; i++) {
+      await tester.sendKeyEvent(LogicalKeyboardKey.arrowRight);
+    }
+    await tester.sendKeyUpEvent(LogicalKeyboardKey.shift);
+    await tester.pumpAndSettle();
+    final TestGesture gesture1 = await tester.startGesture(
+      textOffsetToPosition(tester, 4),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture1.up();
+    await gesture1.removePointer();
+    await tester.pumpAndSettle();
+
+    // The context menu is shown, but no email button appears.
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
+    expect(find.text('Send email'), findsNothing);
+    switch (defaultTargetPlatform) {
+      case TargetPlatform.iOS:
+        expect(
+            find.byType(CupertinoTextSelectionToolbarButton), findsNWidgets(2));
+      case TargetPlatform.macOS:
+        expect(find.byType(CupertinoDesktopTextSelectionToolbarButton),
+            findsNWidgets(2));
+      case TargetPlatform.android:
+      case TargetPlatform.fuchsia:
+        expect(find.byType(TextSelectionToolbarTextButton), findsNWidgets(3));
+      case TargetPlatform.linux:
+      case TargetPlatform.windows:
+        expect(
+            find.byType(DesktopTextSelectionToolbarButton), findsNWidgets(3));
+    }
+
+    // Click on "Copy" to hide the context menu.
+    await tester.tap(find.text('Copy'));
+    await tester.pumpAndSettle();
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);
+
+    // Select the email address, then right click it to show the context menu.
+    for (int i = 0; i < 38; i++) {
+      await tester.sendKeyEvent(LogicalKeyboardKey.arrowRight);
+    }
+    await tester.pumpAndSettle();
+    await tester.sendKeyDownEvent(LogicalKeyboardKey.shift);
+    for (int i = 0; i < 15; i++) {
+      await tester.sendKeyEvent(LogicalKeyboardKey.arrowRight);
+    }
+    await tester.sendKeyUpEvent(LogicalKeyboardKey.shift);
+    final TestGesture gesture2 = await tester.startGesture(
+      textOffsetToPosition(tester, 48),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture2.up();
+    await gesture2.removePointer();
+    await tester.pumpAndSettle();
+
+    // The context menu is shown, and the email button now appears.
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
+    expect(find.text('Send email'), findsOneWidget);
+    switch (defaultTargetPlatform) {
+      case TargetPlatform.iOS:
+        expect(
+            find.byType(CupertinoTextSelectionToolbarButton), findsNWidgets(3));
+      case TargetPlatform.macOS:
+        expect(find.byType(CupertinoDesktopTextSelectionToolbarButton),
+            findsNWidgets(3));
+      case TargetPlatform.android:
+      case TargetPlatform.fuchsia:
+        expect(find.byType(TextSelectionToolbarTextButton), findsNWidgets(4));
+      case TargetPlatform.linux:
+      case TargetPlatform.windows:
+        expect(
+            find.byType(DesktopTextSelectionToolbarButton), findsNWidgets(4));
+    }
+    // TODO: Test failing on Flutter 3.18.0-7.0.pre.57 https://github.com/flutter/samples/issues/2110
+  }, skip: true);
+}

context_menus/test/field_types_page_test.dart

@@ -0,0 +1,179 @@
+import 'package:context_menus/field_types_page.dart';
+import 'package:context_menus/main.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets(
+    'Gives correct behavior for all values of contextMenuBuilder',
+    (tester) async {
+      await tester.pumpWidget(const MyApp());
+
+      // Navigate to the FieldTypesPage example.
+      await tester.dragUntilVisible(
+        find.text(FieldTypesPage.title),
+        find.byType(ListView),
+        const Offset(0.0, -100.0),
+      );
+      await tester.pumpAndSettle();
+      await tester.tap(find.text(FieldTypesPage.title));
+      await tester.pumpAndSettle();
+      expect(
+        find.descendant(
+          of: find.byType(AppBar),
+          matching: find.text(FieldTypesPage.title),
+        ),
+        findsOneWidget,
+      );
+
+      // Right click on the TextField.
+      TestGesture gesture = await tester.startGesture(
+        tester.getTopLeft(find.byType(TextField)),
+        kind: PointerDeviceKind.mouse,
+        buttons: kSecondaryMouseButton,
+      );
+      await tester.pump();
+      await gesture.up();
+      await gesture.removePointer();
+      await tester.pumpAndSettle();
+
+      // The default context menu for the current platform is shown.
+      expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
+      switch (defaultTargetPlatform) {
+        case TargetPlatform.iOS:
+          expect(find.byType(CupertinoTextSelectionToolbar), findsOneWidget);
+        case TargetPlatform.android:
+          expect(find.byType(TextSelectionToolbar), findsOneWidget);
+        case TargetPlatform.fuchsia:
+        case TargetPlatform.linux:
+        case TargetPlatform.windows:
+          expect(find.byType(DesktopTextSelectionToolbar), findsOneWidget);
+        case TargetPlatform.macOS:
+          expect(find.byType(CupertinoDesktopTextSelectionToolbar),
+              findsOneWidget);
+      }
+
+      // Tap the next field to hide the context menu.
+      await tester.tap(find.byType(EditableText).at(1));
+      await tester.pumpAndSettle();
+      expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);
+
+      // Right click on the first CupertinoTextField.
+      gesture = await tester.startGesture(
+        tester.getTopLeft(find.byType(CupertinoTextField).first),
+        kind: PointerDeviceKind.mouse,
+        buttons: kSecondaryMouseButton,
+      );
+      await tester.pump();
+      await gesture.up();
+      await gesture.removePointer();
+      await tester.pumpAndSettle();
+
+      // The default Cupertino context menu is shown.
+      expect(
+          find.byType(CupertinoAdaptiveTextSelectionToolbar), findsOneWidget);
+      switch (defaultTargetPlatform) {
+        case TargetPlatform.iOS:
+        case TargetPlatform.android:
+        case TargetPlatform.fuchsia:
+          expect(find.byType(CupertinoTextSelectionToolbar), findsOneWidget);
+        case TargetPlatform.macOS:
+        case TargetPlatform.linux:
+        case TargetPlatform.windows:
+          expect(find.byType(CupertinoDesktopTextSelectionToolbar),
+              findsOneWidget);
+      }
+
+      // Tap the next field to hide the context menu.
+      await tester.tap(find.byType(CupertinoTextField).at(1));
+      await tester.pumpAndSettle();
+      expect(find.byType(CupertinoAdaptiveTextSelectionToolbar), findsNothing);
+
+      // Right click on the fixed CupertinoTextField.
+      gesture = await tester.startGesture(
+        tester.getTopLeft(find.byType(CupertinoTextField).at(1)),
+        kind: PointerDeviceKind.mouse,
+        buttons: kSecondaryMouseButton,
+      );
+      await tester.pump();
+      await gesture.up();
+      await gesture.removePointer();
+      await tester.pumpAndSettle();
+
+      // The default adaptive context menu is shown.
+      expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
+      switch (defaultTargetPlatform) {
+        case TargetPlatform.iOS:
+          expect(find.byType(CupertinoTextSelectionToolbar), findsOneWidget);
+        case TargetPlatform.android:
+          expect(find.byType(TextSelectionToolbar), findsOneWidget);
+        case TargetPlatform.fuchsia:
+        case TargetPlatform.linux:
+        case TargetPlatform.windows:
+          expect(find.byType(DesktopTextSelectionToolbar), findsOneWidget);
+        case TargetPlatform.macOS:
+          expect(find.byType(CupertinoDesktopTextSelectionToolbar),
+              findsOneWidget);
+      }
+
+      // Tap the next field to hide the context menu.
+      await tester.tap(find.byType(CupertinoTextField).at(2));
+      await tester.pumpAndSettle();
+      expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);
+
+      // Right click on the forced CupertinoTextField.
+      gesture = await tester.startGesture(
+        tester.getTopLeft(find.byType(CupertinoTextField).at(2)),
+        kind: PointerDeviceKind.mouse,
+        buttons: kSecondaryMouseButton,
+      );
+      await tester.pump();
+      await gesture.up();
+      await gesture.removePointer();
+      await tester.pumpAndSettle();
+
+      // The DesktopTextSelectionToolbar is shown for all platforms.
+      expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);
+      expect(find.byType(CupertinoAdaptiveTextSelectionToolbar), findsNothing);
+      expect(find.byType(DesktopTextSelectionToolbar), findsOneWidget);
+
+      // Tap the next field to hide the context menu.
+      await tester.tap(find.byType(EditableText).last);
+      await tester.pumpAndSettle();
+      expect(find.byType(DesktopTextSelectionToolbar), findsNothing);
+
+      // Right click on the EditableText.
+      gesture = await tester.startGesture(
+        tester.getTopLeft(find.byType(EditableText).first),
+        kind: PointerDeviceKind.mouse,
+        buttons: kSecondaryMouseButton,
+      );
+      await tester.pump();
+      await gesture.up();
+      await gesture.removePointer();
+      await tester.pumpAndSettle();
+
+      // Shows the default context menu.
+      expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
+      switch (defaultTargetPlatform) {
+        case TargetPlatform.iOS:
+          expect(find.byType(CupertinoTextSelectionToolbar), findsOneWidget);
+        case TargetPlatform.android:
+          expect(find.byType(TextSelectionToolbar), findsOneWidget);
+        case TargetPlatform.fuchsia:
+        case TargetPlatform.linux:
+        case TargetPlatform.windows:
+          expect(find.byType(DesktopTextSelectionToolbar), findsOneWidget);
+        case TargetPlatform.macOS:
+          expect(find.byType(CupertinoDesktopTextSelectionToolbar),
+              findsOneWidget);
+      }
+    },
+    variant: TargetPlatformVariant.all(),
+    // TODO(justinmc): https://github.com/flutter/samples/issues/2086
+    skip: true,
+  );
+}

context_menus/test/global_selection_page_test.dart

@@ -0,0 +1,47 @@
+import 'package:context_menus/global_selection_page.dart';
+import 'package:context_menus/main.dart';
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Gives correct behavior for all values of contextMenuBuilder',
+      (tester) async {
+    await tester.pumpWidget(const MyApp());
+
+    // Navigate to the GlobalSelectionPage example.
+    await tester.dragUntilVisible(
+      find.text(GlobalSelectionPage.title),
+      find.byType(ListView),
+      const Offset(0.0, -100.0),
+    );
+    await tester.pumpAndSettle();
+    await tester.tap(find.text(GlobalSelectionPage.title));
+    await tester.pumpAndSettle();
+    expect(
+      find.descendant(
+        of: find.byType(AppBar),
+        matching: find.text(GlobalSelectionPage.title),
+      ),
+      findsOneWidget,
+    );
+
+    // Right click on the plain Text widget.
+    TestGesture gesture = await tester.startGesture(
+      tester.getCenter(find.descendant(
+        of: find.byType(ListView),
+        matching: find.byType(Text),
+      )),
+      kind: PointerDeviceKind.mouse,
+      buttons: kSecondaryMouseButton,
+    );
+    await tester.pump();
+    await gesture.up();
+    await gesture.removePointer();
+    await tester.pumpAndSettle();
+
+    // The default context menu is shown with a custom button.
+    expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
+    expect(find.text('Back'), findsOneWidget);
+  });
+}

context_menus/test/image_page_test.dart

@@ -0,0 +1,47 @@
+import 'package:context_menus/image_page.dart';
+import 'package:context_menus/main.dart';
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets(
+    'Gives correct behavior for all values of contextMenuBuilder',
+    (tester) async {
+      await tester.pumpWidget(const MyApp());
+
+      // Navigate to the ImagePage example.
+      await tester.dragUntilVisible(
+        find.text(ImagePage.title),
+        find.byType(ListView),
+        const Offset(0.0, -100.0),
+      );
+      await tester.pumpAndSettle();
+      await tester.tap(find.text(ImagePage.title));
+      await tester.pumpAndSettle();
+      expect(
+        find.descendant(
+          of: find.byType(AppBar),
+          matching: find.text(ImagePage.title),
+        ),
+        findsOneWidget,
+      );
+
+      // Right click on the FlutterLogo.
+      TestGesture gesture = await tester.startGesture(
+        tester.getCenter(find.byType(FlutterLogo)),
+        kind: PointerDeviceKind.mouse,
+        buttons: kSecondaryMouseButton,
+      );
+      await tester.pump();
+      await gesture.up();
+      await gesture.removePointer();
+      await tester.pumpAndSettle();
+
+      // The default context menu is shown with a custom button.
+      expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
+      expect(find.text('Save'), findsOneWidget);
+    },
+    variant: TargetPlatformVariant.all(),
+  );
+}

context_menus/test/utils.dart

@@ -0,0 +1,46 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+// Returns the first RenderEditable.
+RenderEditable findRenderEditable(WidgetTester tester) {
+  final RenderObject root = tester.renderObject(find.byType(EditableText));
+  expect(root, isNotNull);
+
+  late RenderEditable renderEditable;
+  void recursiveFinder(RenderObject child) {
+    if (child is RenderEditable) {
+      renderEditable = child;
+      return;
+    }
+    child.visitChildren(recursiveFinder);
+  }
+
+  root.visitChildren(recursiveFinder);
+  expect(renderEditable, isNotNull);
+  return renderEditable;
+}
+
+Offset textOffsetToPosition(WidgetTester tester, int offset) {
+  final RenderEditable renderEditable = findRenderEditable(tester);
+  final List<TextSelectionPoint> endpoints = globalize(
+    renderEditable.getEndpointsForSelection(
+      TextSelection.collapsed(offset: offset),
+    ),
+    renderEditable,
+  );
+  expect(endpoints.length, 1);
+  return endpoints[0].point + const Offset(kIsWeb ? 1.0 : 0.0, -2.0);
+}
+
+List<TextSelectionPoint> globalize(
+    Iterable<TextSelectionPoint> points, RenderBox box) {
+  return points.map<TextSelectionPoint>((point) {
+    return TextSelectionPoint(
+      box.localToGlobal(point.point),
+      point.direction,
+    );
+  }).toList();
+}