feat: add Image support to finder (#88761)

packages/flutter_test/lib/src/finders.dart

@@ -103,6 +103,19 @@ class CommonFinders {
     );
   }
 
+  /// Finds [Image] and [FadeInImage] widgets containing `image` equal to the
+  /// `image` argument.
+  ///
+  /// ## Sample code
+  ///
+  /// ```dart
+  /// expect(find.image(FileImage(File(filePath))), findsOneWidget);
+  /// ```
+  ///
+  /// If the `skipOffstage` argument is true (the default), then this skips
+  /// nodes that are [Offstage] or that are from inactive [Route]s.
+  Finder image(ImageProvider image, { bool skipOffstage = true }) => _WidgetImageFinder(image, skipOffstage: skipOffstage);
+
   /// Finds widgets by searching for one with a particular [Key].
   ///
   /// ## Sample code
@@ -690,6 +703,26 @@ class _WidgetTypeFinder extends MatchFinder {
   }
 }
 
+class _WidgetImageFinder extends MatchFinder {
+  _WidgetImageFinder(this.image, { bool skipOffstage = true }) : super(skipOffstage: skipOffstage);
+
+  final ImageProvider image;
+
+  @override
+  String get description => 'image "$image"';
+
+  @override
+  bool matches(Element candidate) {
+    final Widget widget = candidate.widget;
+    if (widget is Image) {
+      return widget.image == image;
+    } else if (widget is FadeInImage) {
+      return widget.image == image;
+    }
+    return false;
+  }
+}
+
 class _WidgetIconFinder extends MatchFinder {
   _WidgetIconFinder(this.icon, { bool skipOffstage = true }) : super(skipOffstage: skipOffstage);
 

packages/flutter_test/test/finders_test.dart

@@ -2,11 +2,22 @@
 // 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/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
+  group('image', () {
+    testWidgets('finds Image widgets', (WidgetTester tester) async {
+      await tester.pumpWidget(_boilerplate(
+          Image(image: FileImage(File('test'), scale: 1.0))
+      ));
+      expect(find.image(FileImage(File('test'), scale: 1.0)), findsOneWidget);
+    });
+  });
+
   group('text', () {
     testWidgets('finds Text widgets', (WidgetTester tester) async {
       await tester.pumpWidget(_boilerplate(