[flutter_markdown] Fix some memory leaks and activate leak testing [prod-leak-fix]

packages/flutter_markdown/CHANGELOG.md

@@ -1,6 +1,7 @@
-## NEXT
+## 0.7.5
 
 * Updates minimum supported SDK version to Flutter 3.22/Dart 3.4.
+* Fixes some memory leaks.
 
 ## 0.7.4+3
 

packages/flutter_markdown/lib/src/builder.dart

@@ -346,16 +346,20 @@ class MarkdownBuilder implements md.NodeVisitor {
       child = builders[_blocks.last.tag!]!
           .visitText(text, styleSheet.styles[_blocks.last.tag!]);
     } else if (_blocks.last.tag == 'pre') {
-      final ScrollController preScrollController = ScrollController();
-      child = Scrollbar(
-        controller: preScrollController,
-        child: SingleChildScrollView(
-          controller: preScrollController,
-          scrollDirection: Axis.horizontal,
-          padding: styleSheet.codeblockPadding,
-          child: _buildRichText(delegate.formatText(styleSheet, text.text)),
-        ),
-      );
+      child = _ScrollControllerBuilder(
+          builder: (BuildContext context, ScrollController preScrollController,
+              Widget? child) {
+            return Scrollbar(
+              controller: preScrollController,
+              child: SingleChildScrollView(
+                controller: preScrollController,
+                scrollDirection: Axis.horizontal,
+                padding: styleSheet.codeblockPadding,
+                child: child,
+              ),
+            );
+          },
+          child: _buildRichText(delegate.formatText(styleSheet, text.text)));
     } else {
       child = _buildRichText(
         TextSpan(
@@ -448,15 +452,20 @@ class MarkdownBuilder implements md.NodeVisitor {
         }
       } else if (tag == 'table') {
         if (styleSheet.tableColumnWidth is FixedColumnWidth) {
-          final ScrollController tableScrollController = ScrollController();
-          child = Scrollbar(
-            controller: tableScrollController,
-            child: SingleChildScrollView(
-              controller: tableScrollController,
-              scrollDirection: Axis.horizontal,
-              padding: styleSheet.tablePadding,
-              child: _buildTable(),
-            ),
+          child = _ScrollControllerBuilder(
+            builder: (BuildContext context,
+                ScrollController tableScrollController, Widget? child) {
+              return Scrollbar(
+                controller: tableScrollController,
+                child: SingleChildScrollView(
+                  controller: tableScrollController,
+                  scrollDirection: Axis.horizontal,
+                  padding: styleSheet.tablePadding,
+                  child: child,
+                ),
+              );
+            },
+            child: _buildTable(),
           );
         } else {
           child = _buildTable();
@@ -1017,3 +1026,33 @@ class MarkdownBuilder implements md.NodeVisitor {
     }
   }
 }
+
+class _ScrollControllerBuilder extends StatefulWidget {
+  const _ScrollControllerBuilder({
+    required this.builder,
+    this.child,
+  });
+
+  final ValueWidgetBuilder<ScrollController> builder;
+
+  final Widget? child;
+
+  @override
+  State<_ScrollControllerBuilder> createState() =>
+      _ScrollControllerBuilderState();
+}
+
+class _ScrollControllerBuilderState extends State<_ScrollControllerBuilder> {
+  final ScrollController _controller = ScrollController();
+
+  @override
+  void dispose() {
+    _controller.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return widget.builder(context, _controller, widget.child);
+  }
+}

packages/flutter_markdown/pubspec.yaml

@@ -4,7 +4,7 @@ description: A Markdown renderer for Flutter. Create rich text output,
   formatted with simple Markdown tags.
 repository: https://github.com/flutter/packages/tree/main/packages/flutter_markdown
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+flutter_markdown%22
-version: 0.7.4+3
+version: 0.7.5
 
 environment:
   sdk: ^3.4.0

packages/flutter_markdown/test/custom_syntax_test.dart

@@ -276,9 +276,14 @@ class WikilinkSyntax extends md.InlineSyntax {
 class WikilinkBuilder extends MarkdownElementBuilder {
   @override
   Widget visitElementAfter(md.Element element, _) {
-    return Text.rich(TextSpan(
-        text: element.textContent,
-        recognizer: TapGestureRecognizer()..onTap = () {}));
+    final TapGestureRecognizer recognizer = TapGestureRecognizer()
+      ..onTap = () {};
+    return _TapGestureRecognizerDisposer(
+      recognizer: recognizer,
+      child: Text.rich(
+        TextSpan(text: element.textContent, recognizer: recognizer),
+      ),
+    );
   }
 }
 
@@ -460,3 +465,31 @@ class CustomTagBlockSyntax extends md.BlockSyntax {
     return element;
   }
 }
+
+class _TapGestureRecognizerDisposer extends StatefulWidget {
+  const _TapGestureRecognizerDisposer({
+    required this.child,
+    required this.recognizer,
+  });
+
+  final Widget child;
+  final TapGestureRecognizer recognizer;
+
+  @override
+  State<_TapGestureRecognizerDisposer> createState() =>
+      __TapGestureRecognizerDisposerState();
+}
+
+class __TapGestureRecognizerDisposerState
+    extends State<_TapGestureRecognizerDisposer> {
+  @override
+  void dispose() {
+    widget.recognizer.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return widget.child;
+  }
+}

packages/flutter_markdown/test/image_test.dart

@@ -92,6 +92,7 @@ void defineTests() {
     testWidgets(
       'local files should be files on non-web',
       (WidgetTester tester) async {
+        addTearDown(imageCache.clear);
         const String data = '![alt](http.png)';
         await tester.pumpWidget(
           boilerplate(
@@ -131,6 +132,7 @@ void defineTests() {
       'should work with resources',
       (WidgetTester tester) async {
         TestWidgetsFlutterBinding.ensureInitialized();
+        addTearDown(imageCache.clear);
         const String data = '![alt](resource:assets/logo.png)';
         await tester.pumpWidget(
           boilerplate(
@@ -195,6 +197,7 @@ void defineTests() {
     testWidgets(
       'should show properly next to text',
       (WidgetTester tester) async {
+        addTearDown(imageCache.clear);
         const String data = 'Hello ![alt](img#50x50)';
         await tester.pumpWidget(
           boilerplate(
@@ -412,6 +415,7 @@ void defineTests() {
     testWidgets(
       'custom image builder',
       (WidgetTester tester) async {
+        addTearDown(imageCache.clear);
         const String data = '![alt](https://img.png)';
         Widget builder(Uri uri, String? title, String? alt) =>
             Image.asset('assets/logo.png');

packages/flutter_markdown/test/link_test.dart

@@ -142,6 +142,7 @@ void defineTests() {
     testWidgets(
       'multiple inline links with same content should not throw an exception',
       (WidgetTester tester) async {
+        addTearDown(imageCache.clear);
         //Arange
         final Widget toBePumped = boilerplate(
           Column(
@@ -1025,6 +1026,7 @@ void defineTests() {
       // Example 525 from GFM.
       'inline image link text',
       (WidgetTester tester) async {
+        addTearDown(imageCache.clear);
         const String data = '[![moon](moon.jpg)](/uri)';
         MarkdownLink? linkTapResults;
         await tester.pumpWidget(
@@ -1129,6 +1131,7 @@ void defineTests() {
       // Example 528 from GFM.
       'links cannot be nested in image linksinline image link text',
       (WidgetTester tester) async {
+        addTearDown(imageCache.clear);
         const String data = '![[[foo](uri1)](uri2)](uri3)';
         MarkdownLink? linkTapResults;
         await tester.pumpWidget(

packages/flutter_markdown/test/padding_test.dart

@@ -17,6 +17,8 @@ void defineTests() {
       (WidgetTester tester) async {
         const double paddingX = 10.0;
 
+        addTearDown(imageCache.clear);
+
         await tester.pumpWidget(
           boilerplate(
             Markdown(

packages/flutter_markdown/test/scrollable_test.dart

@@ -68,6 +68,7 @@ void defineTests() {
         final ScrollController controller = ScrollController(
           initialScrollOffset: 209.0,
         );
+        addTearDown(controller.dispose);
 
         await tester.pumpWidget(
           boilerplate(