_NoOpCodec review feedback (#149442)

Author: kevmoo

packages/flutter/test/painting/image_provider_network_image_test.dart

@@ -13,7 +13,7 @@ import 'package:flutter_test/flutter_test.dart';
 
 import '../image_data.dart';
 import '../rendering/rendering_tester.dart';
-import 'noop_codec.dart';
+import 'no_op_codec.dart';
 
 void main() {
   TestRenderingFlutterBinding.ensureInitialized();
@@ -242,7 +242,7 @@ void main() {
 
     const NetworkImage provider = NetworkImage(url);
 
-    final MultiFrameImageStreamCompleter completer = provider.loadBuffer(provider, noopCodec) as MultiFrameImageStreamCompleter;
+    final MultiFrameImageStreamCompleter completer = provider.loadBuffer(provider, noOpDecoderBufferCallback) as MultiFrameImageStreamCompleter;
 
     expect(completer.debugLabel, url);
   });

packages/flutter/test/painting/image_provider_test.dart

@@ -15,7 +15,7 @@ import 'package:flutter_test/flutter_test.dart';
 import '../image_data.dart';
 import '../rendering/rendering_tester.dart';
 import 'mocks_for_image_cache.dart';
-import 'noop_codec.dart';
+import 'no_op_codec.dart';
 
 void main() {
   TestRenderingFlutterBinding.ensureInitialized();
@@ -89,7 +89,7 @@ void main() {
     final FileImage provider = FileImage(file);
 
     expect(provider.loadBuffer(provider, (ImmutableBuffer buffer, {int? cacheWidth, int? cacheHeight, bool? allowUpscaling}) async {
-      return Future<Codec>.value(NoopCodec());
+      return Future<Codec>.value(createNoOpCodec());
     }), isA<MultiFrameImageStreamCompleter>());
 
     expect(await error.future, isStateError);
@@ -100,7 +100,7 @@ void main() {
     final File file = fs.file('/blue.png')..createSync(recursive: true)..writeAsBytesSync(kBlueSquarePng);
     final FileImage provider = FileImage(file);
 
-    final MultiFrameImageStreamCompleter completer = provider.loadBuffer(provider, noopCodec) as MultiFrameImageStreamCompleter;
+    final MultiFrameImageStreamCompleter completer = provider.loadBuffer(provider, noOpDecoderBufferCallback) as MultiFrameImageStreamCompleter;
 
     expect(completer.debugLabel, file.path);
   });
@@ -109,7 +109,7 @@ void main() {
     final Uint8List bytes = Uint8List.fromList(kBlueSquarePng);
     final MemoryImage provider = MemoryImage(bytes);
 
-    final MultiFrameImageStreamCompleter completer = provider.loadBuffer(provider, noopCodec) as MultiFrameImageStreamCompleter;
+    final MultiFrameImageStreamCompleter completer = provider.loadBuffer(provider, noOpDecoderBufferCallback) as MultiFrameImageStreamCompleter;
 
     expect(completer.debugLabel, 'MemoryImage(${describeIdentity(bytes)})');
   });
@@ -118,7 +118,7 @@ void main() {
     const String asset = 'images/blue.png';
     final ExactAssetImage provider = ExactAssetImage(asset, bundle: _TestAssetBundle());
     final AssetBundleImageKey key = await provider.obtainKey(ImageConfiguration.empty);
-    final MultiFrameImageStreamCompleter completer = provider.loadBuffer(key, noopCodec) as MultiFrameImageStreamCompleter;
+    final MultiFrameImageStreamCompleter completer = provider.loadBuffer(key, noOpDecoderBufferCallback) as MultiFrameImageStreamCompleter;
 
     expect(completer.debugLabel, asset);
   });
@@ -128,7 +128,7 @@ void main() {
     final ResizeImage provider = ResizeImage(MemoryImage(bytes), width: 40, height: 40);
     final MultiFrameImageStreamCompleter completer = provider.loadBuffer(
       await provider.obtainKey(ImageConfiguration.empty),
-      noopCodec,
+      noOpDecoderBufferCallback,
     ) as MultiFrameImageStreamCompleter;
 
     expect(completer.debugLabel, 'MemoryImage(${describeIdentity(bytes)}) - Resized(40×40)');

packages/flutter/test/painting/noop_codec.dart renamed to packages/flutter/test/painting/no_op_codec.dart

@@ -4,7 +4,20 @@
 
 import 'dart:ui';
 
-class NoopCodec implements Codec {
+/// Returns a [Codec] that throws on all member invocations.
+Codec createNoOpCodec() => _NoOpCodec();
+
+/// Function matching [DecoderBufferCallback] which returns a [Codec]
+/// that throws on all member invocations.
+Future<Codec> noOpDecoderBufferCallback(
+  ImmutableBuffer buffer, {
+  int? cacheWidth,
+  int? cacheHeight,
+  bool? allowUpscaling,
+}) async =>
+    _NoOpCodec();
+
+class _NoOpCodec implements Codec {
   @override
   void dispose() {}
 
@@ -17,11 +30,3 @@ class NoopCodec implements Codec {
   @override
   int get repetitionCount => throw UnimplementedError();
 }
-
-Future<Codec> noopCodec(
-  ImmutableBuffer buffer, {
-  int? cacheWidth,
-  int? cacheHeight,
-  bool? allowUpscaling,
-}) async =>
-    NoopCodec();