analyzer_testing: Move three mock packages

This moves the sources for the mock fixnum, test_reflective_loader,
and vector_math packages to be loaded via multi-line Dart strings.

Change-Id: I95800ebc417afd4a6b1a5103ffd9e69329022cf3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/461526
Commit-Queue: Samuel Rawlins <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: srawlins

pkg/analyzer_testing/lib/mock_packages/mock_packages.dart

@@ -5,6 +5,13 @@
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/physical_file_system.dart';
 import 'package:analyzer_testing/package_root.dart' as package_root;
+import 'package:analyzer_testing/src/mock_packages/fixnum/fixnum.dart'
+    as mock_fixnum;
+import 'package:analyzer_testing/src/mock_packages/mock_library.dart';
+import 'package:analyzer_testing/src/mock_packages/test_reflective_loader/test_reflective_loader.dart'
+    as test_reflective_loader;
+import 'package:analyzer_testing/src/mock_packages/vector_math/vector_math.dart'
+    as mock_vector_math;
 import 'package:analyzer_testing/utilities/extensions/resource_provider.dart';
 import 'package:path/path.dart' as path;
 
@@ -97,7 +104,7 @@ mixin MockPackagesMixin {
   }
 
   Folder addFixnum() {
-    var packageFolder = _addFiles('fixnum');
+    var packageFolder = _addFiles2('fixnum', mock_fixnum.units);
     return packageFolder.getChildAssumingFolder('lib');
   }
 
@@ -144,7 +151,10 @@ mixin MockPackagesMixin {
   }
 
   Folder addTestReflectiveLoader() {
-    var packageFolder = _addFiles('test_reflective_loader');
+    var packageFolder = _addFiles2(
+      'test_reflective_loader',
+      test_reflective_loader.units,
+    );
     return packageFolder.getChildAssumingFolder('lib');
   }
 
@@ -154,11 +164,15 @@ mixin MockPackagesMixin {
   }
 
   Folder addVectorMath() {
-    var packageFolder = _addFiles('vector_math');
+    var packageFolder = _addFiles2('vector_math', mock_vector_math.units);
     return packageFolder.getChildAssumingFolder('lib');
   }
 
   /// Adds files of the given [packageName] to the [resourceProvider].
+  ///
+  /// This method adds files from the sources found in
+  /// [package_root.packageRoot]. The mock sources are being moved to
+  /// `lib/src/mock_sources/`, accessible via [_addFiles2].
   Folder _addFiles(String packageName) {
     Map<String, String> cachedFiles;
     try {
@@ -187,4 +201,21 @@ mixin MockPackagesMixin {
     );
     return packagesFolder.getChildAssumingFolder(packageName);
   }
+
+  /// Adds files of the given [packageName] to the [resourceProvider].
+  Folder _addFiles2(String packageName, List<MockLibraryUnit> units) {
+    var absolutePackagePath = resourceProvider.convertPath(
+      '$packagesRootPath/$packageName/$packageName',
+    );
+    for (var unit in units) {
+      var absoluteUnitPath = resourceProvider.convertPath(
+        '$absolutePackagePath/${unit.path}',
+      );
+      resourceProvider
+          .getFile(absoluteUnitPath)
+          .writeAsStringSync(unit.content);
+    }
+
+    return resourceProvider.getFolder(absolutePackagePath);
+  }
 }

pkg/analyzer_testing/lib/mock_packages/package_content/fixnum/lib/fixnum.dart

@@ -0,0 +1,16 @@
+// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:analyzer_testing/src/mock_packages/mock_library.dart';
+
+/// The set of units that make up the mock 'fixnum' package.
+final List<MockLibraryUnit> units = [_fixnumLibrary];
+
+final _fixnumLibrary = MockLibraryUnit('lib/fixnum.dart', r'''
+library fixnum;
+
+class Int32 {}
+
+class Int64 {}
+''');

pkg/analyzer_testing/lib/mock_packages/package_content/fixnum/pubspec.yaml

@@ -0,0 +1,15 @@
+// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+class MockLibraryUnit {
+  /// The relative path of this compilation unit, relative to the package root.
+  ///
+  /// Typically, this will start with 'lib/'.
+  final String path;
+
+  /// The source content of the compilation unit.
+  final String content;
+
+  MockLibraryUnit(this.path, this.content);
+}