[pointer_interceptor] fix integration test (flutter#1675)

yjbanov · web-flow · commit 951adfe4d0a8 · 2022-04-29T17:39:10.000-07:00
diff --git a/packages/pointer_interceptor/CHANGELOG.md b/packages/pointer_interceptor/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.9.3+1
+
+* Updates example code and integration tests to accomodate hit-testing changes in the Flutter web engine.
+
 ## 0.9.3
 
 * Require minimal version of flutter SDK to be `2.10`
diff --git a/packages/pointer_interceptor/example/integration_test/widget_test.dart b/packages/pointer_interceptor/example/integration_test/widget_test.dart
@@ -11,86 +11,141 @@ import 'package:integration_test/integration_test.dart';
 
 import 'package:pointer_interceptor_example/main.dart' as app;
 
+final Finder nonClickableButtonFinder =
+    find.byKey(const Key('transparent-button'));
+final Finder clickableWrappedButtonFinder =
+    find.byKey(const Key('wrapped-transparent-button'));
+final Finder clickableButtonFinder = find.byKey(const Key('clickable-button'));
+final Finder backgroundFinder =
+    find.byKey(const ValueKey<String>('background-widget'));
+
 void main() {
   IntegrationTestWidgetsFlutterBinding.ensureInitialized();
 
-  group('Widget', () {
-    final Finder nonClickableButtonFinder =
-        find.byKey(const Key('transparent-button'));
-    final Finder clickableWrappedButtonFinder =
-        find.byKey(const Key('wrapped-transparent-button'));
-    final Finder clickableButtonFinder =
-        find.byKey(const Key('clickable-button'));
-
+  group('Without semantics', () {
     testWidgets(
         'on wrapped elements, the browser does not hit the background-html-view',
         (WidgetTester tester) async {
       app.main();
       await tester.pumpAndSettle();
 
-      final html.Element? element =
-          _getHtmlElementFromFinder(clickableButtonFinder, tester);
-
-      if (html.document.querySelector('flt-glass-pane')?.shadowRoot != null) {
-        // In flutter master...
-        expect(element?.id, isNot('background-html-view'));
-      } else {
-        // In previous versions (--web-renderer=html only)...
-        expect(element?.tagName.toLowerCase(), 'flt-platform-view');
-        final html.Element? platformViewRoot =
-            element?.shadowRoot?.getElementById('background-html-view');
-        expect(platformViewRoot, isNull);
-      }
-    });
+      final html.Element element =
+          _getHtmlElementAtCenter(clickableButtonFinder, tester);
+
+      expect(element.id, isNot('background-html-view'));
+    }, semanticsEnabled: false);
 
     testWidgets(
         'on wrapped elements with intercepting set to false, the browser hits the background-html-view',
         (WidgetTester tester) async {
       app.main();
       await tester.pumpAndSettle();
 
-      final html.Element? element =
-          _getHtmlElementFromFinder(clickableWrappedButtonFinder, tester);
-
-      if (html.document.querySelector('flt-glass-pane')?.shadowRoot != null) {
-        // In flutter master...
-        expect(element?.id, 'background-html-view');
-      } else {
-        // In previous versions (--web-renderer=html only)...
-        expect(element?.tagName.toLowerCase(), 'flt-platform-view');
-        final html.Element? platformViewRoot =
-            element?.shadowRoot?.getElementById('background-html-view');
-        expect(platformViewRoot, isNotNull);
-      }
-    });
+      final html.Element element =
+          _getHtmlElementAtCenter(clickableWrappedButtonFinder, tester);
+
+      expect(element.id, 'background-html-view');
+    }, semanticsEnabled: false);
 
     testWidgets(
         'on unwrapped elements, the browser hits the background-html-view',
         (WidgetTester tester) async {
       app.main();
       await tester.pumpAndSettle();
 
-      final html.Element? element =
-          _getHtmlElementFromFinder(nonClickableButtonFinder, tester);
-
-      if (html.document.querySelector('flt-glass-pane')?.shadowRoot != null) {
-        // In flutter master...
-        expect(element?.id, 'background-html-view');
-      } else {
-        // In previous versions (--web-renderer=html only)...
-        expect(element?.tagName.toLowerCase(), 'flt-platform-view');
-        final html.Element? platformViewRoot =
-            element?.shadowRoot?.getElementById('background-html-view');
-        expect(platformViewRoot, isNotNull);
-      }
+      final html.Element element =
+          _getHtmlElementAtCenter(nonClickableButtonFinder, tester);
+
+      expect(element.id, 'background-html-view');
+    }, semanticsEnabled: false);
+
+    testWidgets('on background directly', (WidgetTester tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+
+      final html.Element element =
+          _getHtmlElementAt(tester.getTopLeft(backgroundFinder));
+
+      expect(element.id, 'background-html-view');
+    }, semanticsEnabled: false);
+  });
+
+  group('With semantics', () {
+    testWidgets('finds semantics of wrapped widgets',
+        (WidgetTester tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+
+      final html.Element element =
+          _getHtmlElementAtCenter(clickableButtonFinder, tester);
+
+      expect(element.tagName.toLowerCase(), 'flt-semantics');
+      expect(element.getAttribute('aria-label'), 'Works As Expected');
+    });
+
+    testWidgets(
+        'finds semantics of wrapped widgets with intercepting set to false',
+        (WidgetTester tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+
+      final html.Element element =
+          _getHtmlElementAtCenter(clickableWrappedButtonFinder, tester);
+
+      expect(element.tagName.toLowerCase(), 'flt-semantics');
+      expect(element.getAttribute('aria-label'),
+          'Never calls onPressed transparent');
+    });
+
+    testWidgets('finds semantics of unwrapped elements',
+        (WidgetTester tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+
+      final html.Element element =
+          _getHtmlElementAtCenter(nonClickableButtonFinder, tester);
+
+      expect(element.tagName.toLowerCase(), 'flt-semantics');
+      expect(element.getAttribute('aria-label'), 'Never calls onPressed');
+    });
+
+    // Notice that, when hit-testing the background platform view, instead of
+    // finding a semantics node, the platform view itself is found. This is
+    // because the platform view does not add interactive semantics nodes into
+    // the framework's semantics tree. Instead, its semantics is determined by
+    // the HTML content of the platform view itself. Flutter's semantics tree
+    // simply allows the hit test to land on the platform view by making itself
+    // hit test transparent.
+    testWidgets('on background directly', (WidgetTester tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+
+      final html.Element element =
+          _getHtmlElementAt(tester.getTopLeft(backgroundFinder));
+
+      expect(element.id, 'background-html-view');
     });
   });
 }
 
-// This functions locates a widget from a Finder, and asks the browser what's the
-// DOM element in the center of the coordinates of the widget. (Returns *which*
-// DOM element will handle Mouse interactions first at those coordinates.)
-html.Element? _getHtmlElementFromFinder(Finder finder, WidgetTester tester) {
+// Calls [_getHtmlElementAt] passing it the center of the widget identified by
+// the `finder`.
+html.Element _getHtmlElementAtCenter(Finder finder, WidgetTester tester) {
   final Offset point = tester.getCenter(finder);
-  return html.document.elementFromPoint(point.dx.toInt(), point.dy.toInt());
+  return _getHtmlElementAt(point);
+}
+
+// Locates the DOM element at the given `point` using `elementFromPoint`.
+//
+// `elementFromPoint` is an approximate proxy for a hit test, although it's
+// sensitive to the presence of shadow roots and browser quirks (not all
+// browsers agree on what it should return in all situations). Since this test
+// runs only in Chromium, it relies on Chromium's behavior.
+html.Element _getHtmlElementAt(Offset point) {
+  // Probe at the shadow so the browser reports semantics nodes in addition to
+  // platform view elements. If probed from `html.document` the browser hides
+  // the contents of <flt-glass-name> as an implementation detail.
+  final html.ShadowRoot glassPaneShadow =
+      html.document.querySelector('flt-glass-pane')!.shadowRoot!;
+  return glassPaneShadow.elementFromPoint(point.dx.toInt(), point.dy.toInt())!;
 }
diff --git a/packages/pointer_interceptor/example/lib/main.dart b/packages/pointer_interceptor/example/lib/main.dart
@@ -116,6 +116,7 @@ class _MyHomePageState extends State<MyHomePage> {
                 alignment: Alignment.center,
                 children: <Widget>[
                   HtmlElement(
+                    key: const ValueKey<String>('background-widget'),
                     onClick: () {
                       _clickedOn('html-element');
                     },
@@ -134,7 +135,8 @@ class _MyHomePageState extends State<MyHomePage> {
                         intercepting: false,
                         child: ElevatedButton(
                           key: const Key('wrapped-transparent-button'),
-                          child: const Text('Never calls onPressed'),
+                          child:
+                              const Text('Never calls onPressed transparent'),
                           onPressed: () {
                             _clickedOn('wrapped-transparent-button');
                           },
diff --git a/packages/pointer_interceptor/pubspec.yaml b/packages/pointer_interceptor/pubspec.yaml
@@ -2,7 +2,7 @@ name: pointer_interceptor
 description: A widget to prevent clicks from being swallowed by underlying HtmlElementViews on the web.
 repository: https://github.com/flutter/packages/tree/main/packages/pointer_interceptor
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+pointer_interceptor%22
-version: 0.9.3
+version: 0.9.3+1
 
 environment:
   sdk: ">=2.12.0 <3.0.0"
