Lookup the package config location for Dart and Flutter test targets

packages/devtools_app/lib/src/shared/server/_extensions_api.dart

@@ -8,6 +8,9 @@ part of 'server.dart';
 /// serve their assets on the server, and return the list of available
 /// extensions here.
 Future<List<DevToolsExtensionConfig>> refreshAvailableExtensions(
+  // TODO(https://github.com/flutter/devtools/issues/7944): pass the URI to the
+  // package config file instead of passing the app root and rebulding the URI
+  // to the package config file.
   Uri? appRoot,
 ) async {
   _log.fine('refreshAvailableExtensions for app root: ${appRoot.toString()}');

packages/devtools_app_shared/CHANGELOG.md

@@ -1,4 +1,8 @@
 ## 0.2.2-wip
+* Lookup the connected app package root from an expression evaluation when
+the connected app is a Dart or Flutter test.
+* Added a field `logExceptions` to `EvalOnDartLibrary` that defaults to true but
+can be disabled to prevent exceptions from being logged to console.
 * Add `caseInsensitiveFuzzyMatch` extension method on `String`.
 * Add common widgets `DevToolsClearableTextField`, `InputDecorationSuffixButton`,
 and `RoundedDropDownButton`.

packages/devtools_app_shared/lib/src/service/eval_on_dart_library.dart

@@ -40,6 +40,7 @@ class EvalOnDartLibrary extends DisposableController
     ValueListenable<IsolateRef?>? isolate,
     this.disableBreakpoints = true,
     this.oneRequestAtATime = false,
+    this.logExceptions = true,
   }) : _clientId = Random().nextInt(1000000000) {
     _libraryRef = Completer<LibraryRef>();
 
@@ -60,6 +61,9 @@ class EvalOnDartLibrary extends DisposableController
   /// Whether to disable breakpoints triggered while evaluating expressions.
   final bool disableBreakpoints;
 
+  /// Whether to log exceptions to stdout on failed evaluations.
+  final bool logExceptions;
+
   /// An ID unique to this instance, so that [asyncEval] keeps working even if
   /// the devtool is opened on multiple tabs at the same time.
   final int _clientId;
@@ -261,7 +265,7 @@ class EvalOnDartLibrary extends DisposableController
   }
 
   void _handleError(Object e, StackTrace stack) {
-    if (_disposed) return;
+    if (_disposed || !logExceptions) return;
 
     if (e is RPCError) {
       _log.shout('RPCError: $e', e, stack);

packages/devtools_app_shared/lib/src/service/service_manager.dart

@@ -11,11 +11,13 @@ import 'package:devtools_shared/devtools_shared.dart';
 import 'package:flutter/foundation.dart';
 import 'package:logging/logging.dart';
 import 'package:meta/meta.dart';
+import 'package:path/path.dart' as path;
 import 'package:vm_service/vm_service.dart' hide Error;
 
 import '../utils/utils.dart';
 import 'connected_app.dart';
 import 'dtd_manager.dart';
+import 'eval_on_dart_library.dart' hide SentinelException;
 import 'flutter_version.dart';
 import 'isolate_manager.dart';
 import 'isolate_state.dart';
@@ -522,30 +524,90 @@ class ServiceManager<T extends VmService> {
     // VM service connection spawned from `dart test` or `flutter test`).
     if (packageRootUriString?.endsWith('.dart') ?? false) {
       final rootLibrary = await _mainIsolateRootLibrary();
-      final testTargetFileUriString =
-          (rootLibrary?.dependencies ?? <LibraryDependency>[])
-              .firstWhereOrNull((dep) => dep.prefix == 'test')
-              ?.target
-              ?.uri;
-      if (testTargetFileUriString != null) {
+      if (rootLibrary != null) {
+        packageRootUriString = (await _lookupPackageRootByEval(rootLibrary)) ??
+            // TODO(kenz): remove this fallback once all test bootstrap
+            // generators include the `packageConfigLocation` constant we
+            // can evaluate.
+            await _lookupPackageRootByImportPrefix(
+              rootLibrary,
+              dtdManager,
+            );
+      }
+    }
+    _log.fine(
+      '[connectedAppPackageRoot] package root for test target: '
+      '$packageRootUriString',
+    );
+    return packageRootUriString == null
+        ? null
+        : Uri.parse(packageRootUriString);
+  }
+
+  Future<String?> _lookupPackageRootByEval(Library rootLibrary) async {
+    final eval = EvalOnDartLibrary(
+      rootLibrary.uri!,
+      this.service! as VmService,
+      serviceManager: this,
+      // Swallow exceptions since this evaluation may be called on an older
+      // version of package:test where we do not expect the evaluation to
+      // succeed.
+      logExceptions: false,
+    );
+    final evalDisposable = Disposable();
+    try {
+      final packageConfig = (await eval.evalInstance(
+        'packageConfigLocation',
+        isAlive: evalDisposable,
+      ))
+          .valueAsString;
+
+      // TODO(https://github.com/flutter/devtools/issues/7944): return the
+      // unmodified package config location. For this case, be sure to handle
+      // invalid values like the empty String or 'null'.
+      final packageConfigIdentifier =
+          path.join('.dart_tool', 'package_config.json');
+      if (packageConfig?.endsWith(packageConfigIdentifier) ?? false) {
         _log.fine(
-          '[connectedAppPackageRoot] detected test library from root library '
-          'imports: $testTargetFileUriString',
+          '[connectedAppPackageRoot] detected test package config from root '
+          'library eval: $packageConfig.',
         );
-        packageRootUriString = await packageRootFromFileUriString(
-          testTargetFileUriString,
-          dtd: dtdManager.connection.value,
-        );
-        _log.fine(
-          '[connectedAppPackageRoot] package root for test target: '
-          '$packageRootUriString',
+        return packageConfig!.substring(
+          0,
+          // Minus 1 to remove the trailing slash.
+          packageConfig.length - packageConfigIdentifier.length - 1,
         );
       }
+    } catch (_) {
+      // Fail gracefully if the evaluation fails.
+    } finally {
+      evalDisposable.dispose();
     }
+    return null;
+  }
 
-    return packageRootUriString == null
-        ? null
-        : Uri.parse(packageRootUriString);
+  Future<String?> _lookupPackageRootByImportPrefix(
+    Library rootLibrary,
+    DTDManager dtdManager,
+  ) async {
+    final testTargetFileUriString =
+        (rootLibrary.dependencies ?? <LibraryDependency>[])
+            .firstWhereOrNull((dep) => dep.prefix == 'test')
+            ?.target
+            ?.uri;
+    if (testTargetFileUriString != null) {
+      _log.fine(
+        '[connectedAppPackageRoot] detected test library from root library '
+        'imports: $testTargetFileUriString',
+      );
+      // TODO(https://github.com/flutter/devtools/issues/7944): return the
+      // unmodified package config location.
+      return await packageRootFromFileUriString(
+        testTargetFileUriString,
+        dtd: dtdManager.connection.value,
+      );
+    }
+    return null;
   }
 
   Future<Library?> _mainIsolateRootLibrary() async {

packages/devtools_app_shared/pubspec.yaml

@@ -16,6 +16,7 @@ dependencies:
     sdk: flutter
   logging: ^1.1.1
   meta: ^1.9.1
+  path: ^1.8.0
   pointer_interceptor: ^0.9.3+3
   url_launcher: ^6.1.0
   vm_service: ^14.2.1

packages/devtools_shared/lib/src/extensions/extension_manager.dart

@@ -105,13 +105,13 @@ class ExtensionsManager {
           if (root.toString() == rootFileUriString) continue;
 
           await _addExtensionsForRoot(
-            // TODO(https://github.com/dart-lang/pub/issues/4218): this logic
+            // TODO(https://github.com/flutter/devtools/issues/7944): this logic
             // assumes that the .dart_tool folder containing the
             // package_config.json file is in the same directory as the
             // pubspec.yaml file (since `dartToolingDaemon.getProjectRoots`
             // returns all directories within the IDE workspace roots that have
             // a pubspec.yaml file). This may be an incorrect assumption for
-            // monorepos.
+            // pub workspaces.
             root.toString(),
             logs: logs,
             parsingErrors: parsingErrors,
@@ -143,9 +143,9 @@ class ExtensionsManager {
     _assertUriFormat(rootFileUriString);
     final List<Extension> extensions;
     try {
-      // TODO(https://github.com/dart-lang/pub/issues/4218): this assumes that
-      // the .dart_tool/package_config.json file is in the package root, which
-      // may be an incorrect assumption for monorepos.
+      // TODO(https://github.com/flutter/devtools/issues/7944): this assumes
+      // that the .dart_tool/package_config.json file is in the package root,
+      // which may be an incorrect assumption for pub workspaces.
       final packageConfigPath = path.posix.join(
         rootFileUriString,
         '.dart_tool',
@@ -188,9 +188,10 @@ class ExtensionsManager {
         final extensionConfig = DevToolsExtensionConfig.parse({
           ...config,
           DevToolsExtensionConfig.extensionAssetsPathKey: location,
-          // TODO(kenz): for monorepos, we may want to store the
-          // devtools_options.yaml at the same location as the workspace's
-          // .dart_tool/package_config.json file.
+          // TODO(https://github.com/flutter/devtools/issues/7944): for pub
+          // workspaces, we may want to store the devtools_options.yaml at the
+          // same location as the workspace's .dart_tool/package_config.json
+          // file.
           DevToolsExtensionConfig.devtoolsOptionsUriKey:
               path.join(rootFileUriString, devtoolsOptionsFileName),
           DevToolsExtensionConfig.isPubliclyHostedKey: isPubliclyHosted,