Allow client to specify how to find the package config (#2199)

Author: elliette

dwds/CHANGELOG.md

@@ -1,4 +1,8 @@
-## 20.0.2-wip
+## 21.0.0-wip
+
+**Breaking changes**
+
+- Allow clients to specify where to find the package config. - [#2199](https://github.com/dart-lang/webdev/pull/2199).
 
 ## 20.0.1
 

dwds/lib/src/loaders/legacy.dart

@@ -66,6 +66,16 @@ class LegacyStrategy extends LoadStrategy {
   /// an app URI.
   final String? Function(String appUri) _serverPathForAppUri;
 
+  /// Returns the absolute path to the app's package config, determined by the
+  /// app's [entrypoint] path.
+  ///
+  /// Example:
+  ///
+  ///  main_module.bootstrap.js
+  ///   -> /Users/john_doe/my_dart_app/.dart_tool/package_config.json
+  ///
+  final String? Function(String entrypoint) _packageConfigLocator;
+
   final Uri? _appEntrypoint;
 
   LegacyStrategy(
@@ -77,6 +87,7 @@ class LegacyStrategy extends LoadStrategy {
     this._moduleInfoForProvider,
     AssetReader assetReader,
     this._appEntrypoint,
+    this._packageConfigLocator,
   ) : super(assetReader);
 
   @override
@@ -122,4 +133,8 @@ class LegacyStrategy extends LoadStrategy {
 
   @override
   Uri? get appEntrypoint => _appEntrypoint;
+
+  @override
+  String? packageConfigLocator(String entrypoint) =>
+      _packageConfigLocator(entrypoint);
 }

dwds/lib/src/loaders/require.dart

@@ -283,4 +283,7 @@ if(!window.\$requireLoader) {
   @override
   Future<Map<String, ModuleInfo>> moduleInfoForEntrypoint(String entrypoint) =>
       _moduleInfoForProvider(metadataProviderFor(entrypoint));
+
+  @override
+  String? packageConfigLocator(String entrypoint) => null;
 }

dwds/lib/src/loaders/strategy.dart

@@ -5,6 +5,8 @@
 import 'package:dwds/src/debugging/metadata/provider.dart';
 import 'package:dwds/src/readers/asset_reader.dart';
 import 'package:dwds/src/services/expression_compiler.dart';
+import 'package:dwds/src/utilities/dart_uri.dart';
+import 'package:path/path.dart' as p;
 import 'package:shelf/shelf.dart';
 
 late LoadStrategy _globalLoadStrategy;
@@ -16,6 +18,7 @@ LoadStrategy get globalLoadStrategy => _globalLoadStrategy;
 abstract class LoadStrategy {
   final AssetReader _assetReader;
   final _providers = <String, MetadataProvider>{};
+  String? _packageConfigPath;
 
   LoadStrategy(this._assetReader);
 
@@ -103,6 +106,29 @@ abstract class LoadStrategy {
   /// an app URI.
   String? serverPathForAppUri(String appUri);
 
+  /// Returns the absolute path to the app's package config, determined by the
+  /// app's [entrypoint] path.
+  ///
+  /// Example:
+  ///
+  ///  main_module.bootstrap.js
+  ///   -> /Users/john_doe/my_dart_app/.dart_tool/package_config.json
+  ///
+  String? packageConfigLocator(String entrypoint);
+
+  /// The absolute path to the app's package config, or null if not provided by
+  /// [packageConfigLocator].
+  String get packageConfigPath {
+    return _packageConfigPath ?? _defaultPackageConfigPath;
+  }
+
+  /// The default package config path, if none is provided by the load strategy.
+  String get _defaultPackageConfigPath => p.join(
+        DartUri.currentDirectory,
+        '.dart_tool',
+        'package_config.json',
+      );
+
   /// Returns the [MetadataProvider] for the application located at the provided
   /// [entrypoint].
   MetadataProvider metadataProviderFor(String entrypoint) {
@@ -117,6 +143,7 @@ abstract class LoadStrategy {
   /// provided [entrypoint].
   void trackEntrypoint(String entrypoint) {
     final metadataProvider = MetadataProvider(entrypoint, _assetReader);
+    _packageConfigPath = packageConfigLocator(entrypoint);
     _providers[metadataProvider.entrypoint] = metadataProvider;
   }
 }

dwds/lib/src/utilities/dart_uri.dart

@@ -151,11 +151,8 @@ class DartUri {
 
   /// Record library and script uris to enable resolving library and script paths.
   static Future<void> initialize() async {
-    final packagesUri =
-        p.toUri(p.join(currentDirectory, '.dart_tool/package_config.json'));
-
     clear();
-    await _loadPackageConfig(packagesUri);
+    await _loadPackageConfig(p.toUri(globalLoadStrategy.packageConfigPath));
   }
 
   /// Clear the uri resolution tables.

dwds/lib/src/version.dart

@@ -1,6 +1,6 @@
 name: dwds
 # Every time this changes you need to run `dart run build_runner build`.
-version: 20.0.2-wip
+version: 21.0.0-wip
 description: >-
   A service that proxies between the Chrome debug protocol and the Dart VM
   service protocol.

dwds/pubspec.yaml

@@ -5,6 +5,7 @@
 @TestOn('vm')
 @Timeout(Duration(minutes: 2))
 
+import 'package:dwds/asset_reader.dart';
 import 'package:dwds/src/loaders/strategy.dart';
 import 'package:dwds/src/utilities/dart_uri.dart';
 import 'package:test/test.dart';
@@ -13,6 +14,10 @@ import 'package:test_common/logging.dart';
 import 'fixtures/fakes.dart';
 
 class TestStrategy extends FakeStrategy {
+  TestStrategy(
+    AssetReader assetReader,
+  ) : super(assetReader);
+
   @override
   String? serverPathForAppUri(String appUrl) {
     final appUri = Uri.parse(appUrl);
@@ -30,7 +35,7 @@ class TestStrategy extends FakeStrategy {
 }
 
 void main() {
-  globalLoadStrategy = TestStrategy();
+  globalLoadStrategy = TestStrategy(FakeAssetReader());
   group('DartUri', () {
     test('parses package : paths', () {
       final uri = DartUri('package:path/path.dart');

dwds/test/dart_uri_test.dart

@@ -6,6 +6,7 @@
 @Timeout(Duration(minutes: 2))
 import 'dart:async';
 
+import 'package:dwds/asset_reader.dart';
 import 'package:dwds/src/debugging/debugger.dart';
 import 'package:dwds/src/debugging/frame_computer.dart';
 import 'package:dwds/src/debugging/inspector.dart';
@@ -29,6 +30,10 @@ late Locations locations;
 late SkipLists skipLists;
 
 class TestStrategy extends FakeStrategy {
+  TestStrategy(
+    AssetReader assetReader,
+  ) : super(assetReader);
+
   @override
   Future<String> moduleForServerPath(String entrypoint, String appUri) async =>
       'foo.ddc.js';
@@ -82,7 +87,7 @@ void main() async {
     webkitDebugger = FakeWebkitDebugger(scripts: scripts);
     pausedController = StreamController<DebuggerPausedEvent>();
     webkitDebugger.onPaused = pausedController.stream;
-    globalLoadStrategy = TestStrategy();
+    globalLoadStrategy = TestStrategy(FakeAssetReader());
     final root = 'fakeRoot';
     locations = Locations(
       FakeAssetReader(sourceMap: sourceMapContents),

dwds/test/debugger_test.dart

@@ -35,9 +35,9 @@ void main() async {
     late StreamController<DebuggerPausedEvent> pausedController;
     late StreamController<Event> debugEventController;
     setUp(() async {
-      globalLoadStrategy = FakeStrategy();
-
       final assetReader = FakeAssetReader(sourceMap: '');
+      globalLoadStrategy = FakeStrategy(assetReader);
+
       final modules = FakeModules();
 
       final webkitDebugger = FakeWebkitDebugger();

dwds/test/expression_evaluator_test.dart

@@ -311,7 +311,11 @@ class FakeExecutionContext extends ExecutionContext {
   FakeExecutionContext();
 }
 
-class FakeStrategy implements LoadStrategy {
+class FakeStrategy extends LoadStrategy {
+  FakeStrategy(
+    AssetReader assetReader,
+  ) : super(assetReader);
+
   @override
   Future<String> bootstrapFor(String entrypoint) async => 'dummy_bootstrap';
 
@@ -336,6 +340,9 @@ class FakeStrategy implements LoadStrategy {
   @override
   Uri? get appEntrypoint => Uri.parse('package:myapp/main.dart');
 
+  @override
+  String? packageConfigLocator(String entrypoint) => null;
+
   @override
   ReloadConfiguration get reloadConfiguration => ReloadConfiguration.none;
 
@@ -367,9 +374,6 @@ class FakeStrategy implements LoadStrategy {
   MetadataProvider metadataProviderFor(String entrypoint) =>
       MetadataProvider(entrypoint, FakeAssetReader());
 
-  @override
-  void trackEntrypoint(String entrypoint) {}
-
   @override
   Future<Map<String, ModuleInfo>> moduleInfoForEntrypoint(String entrypoint) =>
       throw UnimplementedError();

dwds/test/fixtures/fakes.dart

@@ -19,7 +19,7 @@ void main() {
   late HttpServer server;
   const entryEtag = 'entry etag';
   const nonEntryEtag = 'some etag';
-  final loadStrategy = FakeStrategy();
+  final loadStrategy = FakeStrategy(FakeAssetReader());
 
   group('InjectedHandlerWithoutExtension', () {
     late DwdsInjector injector;

dwds/test/handlers/injector_test.dart

@@ -0,0 +1,68 @@
+// Copyright (c) 2023, 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.
+
+@TestOn('vm')
+@Timeout(Duration(minutes: 1))
+
+import 'package:dwds/asset_reader.dart';
+import 'package:path/path.dart' as p;
+import 'package:test/test.dart';
+import 'package:test_common/test_sdk_configuration.dart';
+
+import 'fixtures/context.dart';
+import 'fixtures/fakes.dart';
+import 'fixtures/project.dart';
+
+class LoadStrategyCustomPackageConfig extends FakeStrategy {
+  LoadStrategyCustomPackageConfig(
+    AssetReader assetReader,
+  ) : super(assetReader);
+
+  @override
+  String? packageConfigLocator(String entrypoint) =>
+      '$entrypoint/custom/package_config/path';
+}
+
+void main() {
+  final provider = TestSdkConfigurationProvider();
+  tearDownAll(provider.dispose);
+
+  final context = TestContext(TestProject.testWithSoundNullSafety, provider);
+
+  setUpAll(() async {
+    await context.setUp();
+  });
+
+  tearDownAll(() async {
+    await context.tearDown();
+  });
+
+  group('Load Strategy', () {
+    group(
+        'When the packageConfigLocator does not specify a package config path',
+        () {
+      final strategy = FakeStrategy(FakeAssetReader());
+
+      test('defaults to "./dart_tool/packageconfig.json"', () {
+        strategy.trackEntrypoint('my_app/entrypoint');
+        expect(
+          p.split(strategy.packageConfigPath).join('/'),
+          endsWith('_testSound/.dart_tool/package_config.json'),
+        );
+      });
+    });
+
+    group('When the packageConfigLocator specifies a package config path', () {
+      final strategy = LoadStrategyCustomPackageConfig(FakeAssetReader());
+
+      test('uses the specified package config path', () {
+        strategy.trackEntrypoint('my_app/entrypoint');
+        expect(
+          strategy.packageConfigPath,
+          equals('my_app/entrypoint/custom/package_config/path'),
+        );
+      });
+    });
+  });
+}

dwds/test/load_strategy_test.dart

@@ -4,6 +4,7 @@
 
 @Timeout(Duration(minutes: 2))
 
+import 'package:dwds/asset_reader.dart';
 import 'package:dwds/src/debugging/location.dart';
 import 'package:dwds/src/loaders/strategy.dart';
 import 'package:dwds/src/utilities/dart_uri.dart';
@@ -23,10 +24,10 @@ void main() {
   const lines = 100;
   const lineLength = 150;
 
-  globalLoadStrategy = MockLoadStrategy();
+  final assetReader = FakeAssetReader(sourceMap: sourceMapContents);
+  globalLoadStrategy = MockLoadStrategy(assetReader);
   final dartUri = DartUri('org-dartlang-app://web/main.dart');
 
-  final assetReader = FakeAssetReader(sourceMap: sourceMapContents);
   final modules = FakeModules(module: _module);
   final locations = Locations(assetReader, modules, '');
   locations.initialize('fake_entrypoint');
@@ -183,6 +184,10 @@ const _serverPath = 'web/main.dart';
 const _sourceMapPath = 'packages/module.js.map';
 
 class MockLoadStrategy extends FakeStrategy {
+  MockLoadStrategy(
+    AssetReader assetReader,
+  ) : super(assetReader);
+
   @override
   Future<String?> moduleForServerPath(
     String entrypoint,

dwds/test/location_test.dart

@@ -6,6 +6,7 @@
 
 import 'package:dwds/src/debugging/metadata/module_metadata.dart';
 import 'package:dwds/src/debugging/metadata/provider.dart';
+import 'package:dwds/src/loaders/strategy.dart';
 import 'package:test/test.dart';
 
 import 'fixtures/fakes.dart';
@@ -40,6 +41,7 @@ const _fileUriMetadata =
     '// intentionally empty: package blah has no dart sources';
 
 void main() {
+  globalLoadStrategy = FakeStrategy(FakeAssetReader());
   test('can parse metadata with empty sources', () async {
     final provider = MetadataProvider(
       'foo.bootstrap.js',

dwds/test/metadata_test.dart

@@ -4,6 +4,7 @@
 
 @Timeout(Duration(minutes: 2))
 
+import 'package:dwds/asset_reader.dart';
 import 'package:dwds/src/debugging/location.dart';
 import 'package:dwds/src/debugging/skip_list.dart';
 import 'package:dwds/src/loaders/strategy.dart';
@@ -14,14 +15,18 @@ import 'package:test/test.dart';
 import 'fixtures/fakes.dart';
 
 class TestStrategy extends FakeStrategy {
+  TestStrategy(
+    AssetReader assetReader,
+  ) : super(assetReader);
+
   @override
   String serverPathForAppUri(String appUri) {
     return 'foo';
   }
 }
 
 void main() {
-  globalLoadStrategy = TestStrategy();
+  globalLoadStrategy = TestStrategy(FakeAssetReader());
 
   late SkipLists skipLists;
   final dartUri = DartUri('org-dartlang-app://web/main.dart');

dwds/test/skip_list_test.dart

@@ -67,7 +67,7 @@ String testPattern(Object obj) {
 }
 
 String testPattern2() {
-  final dog = 'Prismo'; 
+  final dog = 'Prismo';
   final cats = ['Garfield', 'Tom']; // Breakpoint: testPattern2Case1
   final [firstCat, secondCat] = cats;
   print(firstCat); // Breakpoint: testPattern2Case2