Remove hidden dependencies on the default goldenFileComparator. (#146956)

This is part 12 of a broken down version of the #140101 refactor.

This only makes one dependency explicit. Further PRs will do the same for other dependencies, until these APIs have no hidden dependencies.

packages/flutter_goldens/lib/flutter_goldens.dart

@@ -57,21 +57,24 @@ Future<void> testExecutable(FutureOr<void> Function() testMain, {String? namePre
   const Platform platform = LocalPlatform();
   const FileSystem fs = LocalFileSystem();
   if (FlutterPostSubmitFileComparator.isForEnvironment(platform)) {
-    goldenFileComparator = await FlutterPostSubmitFileComparator.fromDefaultComparator(
+    goldenFileComparator = await FlutterPostSubmitFileComparator.fromLocalFileComparator(
+      localFileComparator: goldenFileComparator as LocalFileComparator,
       platform,
       namePrefix: namePrefix,
       log: print,
       fs: fs,
     );
   } else if (FlutterPreSubmitFileComparator.isForEnvironment(platform)) {
-    goldenFileComparator = await FlutterPreSubmitFileComparator.fromDefaultComparator(
+    goldenFileComparator = await FlutterPreSubmitFileComparator.fromLocalFileComparator(
+      localFileComparator: goldenFileComparator as LocalFileComparator,
       platform,
       namePrefix: namePrefix,
       log: print,
       fs: fs,
     );
   } else if (FlutterSkippingFileComparator.isForEnvironment(platform)) {
-    goldenFileComparator = FlutterSkippingFileComparator.fromDefaultComparator(
+    goldenFileComparator = FlutterSkippingFileComparator.fromLocalFileComparator(
+      localFileComparator: goldenFileComparator as LocalFileComparator,
       'Golden file testing is not executed on Cirrus, or LUCI environments '
       'outside of flutter/flutter, or in test shards that are not configured '
       'for using goldctl.',
@@ -80,7 +83,8 @@ Future<void> testExecutable(FutureOr<void> Function() testMain, {String? namePre
       fs: fs,
     );
   } else {
-    goldenFileComparator = await FlutterLocalFileComparator.fromDefaultComparator(
+    goldenFileComparator = await FlutterLocalFileComparator.fromLocalFileComparator(
+      localFileComparator: goldenFileComparator as LocalFileComparator,
       platform,
       log: print,
       fs: fs,
@@ -268,21 +272,19 @@ class FlutterPostSubmitFileComparator extends FlutterGoldenFileComparator {
   });
 
   /// Creates a new [FlutterPostSubmitFileComparator] that mirrors the relative
-  /// path resolution of the default [goldenFileComparator].
+  /// path resolution of the provided `localFileComparator`.
   ///
-  /// The [goldens] and [defaultComparator] parameters are visible for testing
-  /// purposes only.
-  static Future<FlutterPostSubmitFileComparator> fromDefaultComparator(
+  /// The [goldens] parameter is visible for testing purposes only.
+  static Future<FlutterPostSubmitFileComparator> fromLocalFileComparator(
     final Platform platform, {
     SkiaGoldClient? goldens,
-    LocalFileComparator? defaultComparator,
+    required LocalFileComparator localFileComparator,
     String? namePrefix,
     required LogCallback log,
     required FileSystem fs,
   }) async {
-    defaultComparator ??= goldenFileComparator as LocalFileComparator;
     final Directory baseDirectory = FlutterGoldenFileComparator.getBaseDirectory(
-      defaultComparator,
+      localFileComparator,
       platform,
       suffix: 'flutter_goldens_postsubmit.',
       fs: fs,
@@ -354,20 +356,18 @@ class FlutterPreSubmitFileComparator extends FlutterGoldenFileComparator {
   /// Creates a new [FlutterPreSubmitFileComparator] that mirrors the
   /// relative path resolution of the default [goldenFileComparator].
   ///
-  /// The [goldens] and [defaultComparator] parameters are visible for testing
-  /// purposes only.
-  static Future<FlutterGoldenFileComparator> fromDefaultComparator(
+  /// The [goldens] parameter is visible for testing purposes only.
+  static Future<FlutterGoldenFileComparator> fromLocalFileComparator(
     final Platform platform, {
     SkiaGoldClient? goldens,
-    LocalFileComparator? defaultComparator,
+    required LocalFileComparator localFileComparator,
     Directory? testBasedir,
     String? namePrefix,
     required LogCallback log,
     required FileSystem fs,
   }) async {
-    defaultComparator ??= goldenFileComparator as LocalFileComparator;
     final Directory baseDirectory = testBasedir ?? FlutterGoldenFileComparator.getBaseDirectory(
-      defaultComparator,
+      localFileComparator,
       platform,
       suffix: 'flutter_goldens_presubmit.',
       fs: fs,
@@ -447,16 +447,15 @@ class FlutterSkippingFileComparator extends FlutterGoldenFileComparator {
   final String reason;
 
   /// Creates a new [FlutterSkippingFileComparator] that mirrors the
-  /// relative path resolution of the default [goldenFileComparator].
-  static FlutterSkippingFileComparator fromDefaultComparator(
+  /// relative path resolution of the given [localFileComparator].
+  static FlutterSkippingFileComparator fromLocalFileComparator(
     String reason, {
-    LocalFileComparator? defaultComparator,
+    required LocalFileComparator localFileComparator,
     String? namePrefix,
     required LogCallback log,
     required FileSystem fs,
   }) {
-    defaultComparator ??= goldenFileComparator as LocalFileComparator;
-    final Uri basedir = defaultComparator.basedir;
+    final Uri basedir = localFileComparator.basedir;
     final SkiaGoldClient skiaClient = SkiaGoldClient(fs.directory(basedir), log: log);
     return FlutterSkippingFileComparator(
       basedir,
@@ -531,21 +530,20 @@ class FlutterLocalFileComparator extends FlutterGoldenFileComparator with LocalC
   });
 
   /// Creates a new [FlutterLocalFileComparator] that mirrors the
-  /// relative path resolution of the default [goldenFileComparator].
+  /// relative path resolution of the given [localFileComparator].
   ///
-  /// The [goldens], [defaultComparator], and [baseDirectory] parameters are
+  /// The [goldens] and [baseDirectory] parameters are
   /// visible for testing purposes only.
-  static Future<FlutterGoldenFileComparator> fromDefaultComparator(
+  static Future<FlutterGoldenFileComparator> fromLocalFileComparator(
     final Platform platform, {
     SkiaGoldClient? goldens,
-    LocalFileComparator? defaultComparator,
+    required LocalFileComparator localFileComparator,
     Directory? baseDirectory,
     required LogCallback log,
     required FileSystem fs,
   }) async {
-    defaultComparator ??= goldenFileComparator as LocalFileComparator;
     baseDirectory ??= FlutterGoldenFileComparator.getBaseDirectory(
-      defaultComparator,
+      localFileComparator,
       platform,
       fs: fs,
     );

packages/flutter_goldens/test/flutter_goldens_test.dart

@@ -13,6 +13,7 @@ import 'package:file/memory.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter_goldens/flutter_goldens.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:path/path.dart' as path;
 import 'package:platform/platform.dart';
 import 'package:process/process.dart';
 
@@ -851,7 +852,8 @@ void main() {
         fs.directory(_kFlutterRoot).createSync(recursive: true);
         final FakeSkiaGoldClient fakeSkiaClient = FakeSkiaGoldClient();
         expect(fakeSkiaClient.initCalls, 0);
-        FlutterPostSubmitFileComparator.fromDefaultComparator(
+        FlutterPostSubmitFileComparator.fromLocalFileComparator(
+          localFileComparator: LocalFileComparator(Uri.parse('/test'), pathStyle: path.Style.posix),
           platform,
           goldens: fakeSkiaClient,
           log: (String message) => fail('skia gold client printed unexpected output: "$message"'),
@@ -936,7 +938,8 @@ void main() {
         fs.directory(_kFlutterRoot).createSync(recursive: true);
         final FakeSkiaGoldClient fakeSkiaClient = FakeSkiaGoldClient();
         expect(fakeSkiaClient.tryInitCalls, 0);
-        FlutterPostSubmitFileComparator.fromDefaultComparator(
+        FlutterPostSubmitFileComparator.fromLocalFileComparator(
+          localFileComparator: LocalFileComparator(Uri.parse('/test'), pathStyle: path.Style.posix),
           platform,
           goldens: fakeSkiaClient,
           log: (String message) => fail('skia gold client printed unexpected output: "$message"'),
@@ -1037,7 +1040,8 @@ void main() {
         fakeDirectory.uri = Uri.parse('/flutter');
 
         fakeSkiaClient.getExpectationForTestThrowable = const OSError("Can't reach Gold");
-        final FlutterGoldenFileComparator comparator1 = await FlutterLocalFileComparator.fromDefaultComparator(
+        final FlutterGoldenFileComparator comparator1 = await FlutterLocalFileComparator.fromLocalFileComparator(
+          localFileComparator: LocalFileComparator(Uri.parse('/test'), pathStyle: path.Style.posix),
           platform,
           goldens: fakeSkiaClient,
           baseDirectory: fakeDirectory,
@@ -1047,7 +1051,8 @@ void main() {
         expect(comparator1.runtimeType, FlutterSkippingFileComparator);
 
         fakeSkiaClient.getExpectationForTestThrowable =  const SocketException("Can't reach Gold");
-        final FlutterGoldenFileComparator comparator2 = await FlutterLocalFileComparator.fromDefaultComparator(
+        final FlutterGoldenFileComparator comparator2 = await FlutterLocalFileComparator.fromLocalFileComparator(
+          localFileComparator: LocalFileComparator(Uri.parse('/test'), pathStyle: path.Style.posix),
           platform,
           goldens: fakeSkiaClient,
           baseDirectory: fakeDirectory,
@@ -1057,7 +1062,8 @@ void main() {
         expect(comparator2.runtimeType, FlutterSkippingFileComparator);
 
         fakeSkiaClient.getExpectationForTestThrowable =  const FormatException("Can't reach Gold");
-        final FlutterGoldenFileComparator comparator3 = await FlutterLocalFileComparator.fromDefaultComparator(
+        final FlutterGoldenFileComparator comparator3 = await FlutterLocalFileComparator.fromLocalFileComparator(
+          localFileComparator: LocalFileComparator(Uri.parse('/test'), pathStyle: path.Style.posix),
           platform,
           goldens: fakeSkiaClient,
           baseDirectory: fakeDirectory,