fix source map loading and service protocol for flutter web (#39189)

packages/flutter_tools/lib/src/build_runner/resident_web_runner.dart

@@ -66,6 +66,10 @@ class ResidentWebRunner extends ResidentRunner {
   final Device device;
   final FlutterProject flutterProject;
 
+  // Only the debug builds of the web support the service protocol.
+  @override
+  bool get supportsServiceProtocol => isRunningDebug;
+
   WebFs _webFs;
   DebugConnection _debugConnection;
   StreamSubscription<vmservice.Event> _stdOutSub;

packages/flutter_tools/lib/src/build_runner/web_fs.dart

@@ -25,9 +25,11 @@ import '../base/context.dart';
 import '../base/file_system.dart';
 import '../base/io.dart';
 import '../base/os.dart';
+import '../base/platform.dart';
 import '../build_info.dart';
 import '../bundle.dart';
 import '../cache.dart';
+import '../dart/package_map.dart';
 import '../globals.dart';
 import '../project.dart';
 import '../web/chrome.dart';
@@ -178,6 +180,8 @@ class WebFs {
     final Map<String, String> mappedUrls = <String, String>{
       'main.dart.js': 'packages/${flutterProject.manifest.appName}/'
         '${targetBaseName}_web_entrypoint.dart.js',
+      '${targetBaseName}_web_entrypoint.dart.js.map': 'packages/${flutterProject.manifest.appName}/'
+        '${targetBaseName}_web_entrypoint.dart.js.map',
       '${targetBaseName}_web_entrypoint.dart.bootstrap.js': 'packages/${flutterProject.manifest.appName}/'
         '${targetBaseName}_web_entrypoint.dart.bootstrap.js',
       '${targetBaseName}_web_entrypoint.digests': 'packages/${flutterProject.manifest.appName}/'
@@ -206,7 +210,7 @@ class WebFs {
       .addHandler(dwds.handler);
     Cascade cascade = Cascade();
     cascade = cascade.add(handler);
-    cascade = cascade.add(_assetHandler);
+    cascade = cascade.add(_assetHandler(flutterProject));
     final HttpServer server = await httpMultiServerFactory(_kHostName, port);
     shelf_io.serveRequests(server, cascade.handler);
     final Chrome chrome = await chromeLauncher.launch('http://$_kHostName:$port/');
@@ -218,46 +222,74 @@ class WebFs {
     );
   }
 
-  static Future<Response> _assetHandler(Request request) async {
-    if (request.url.path.contains('stack_trace_mapper')) {
-      final File file = fs.file(fs.path.join(
-        artifacts.getArtifactPath(Artifact.engineDartSdkPath),
-        'lib',
-        'dev_compiler',
-        'web',
-        'dart_stack_trace_mapper.js'
-      ));
-      return Response.ok(file.readAsBytesSync(), headers: <String, String>{
-        'Content-Type': 'text/javascript',
-      });
-    } else if (request.url.path.contains('require.js')) {
-      final File file = fs.file(fs.path.join(
-        artifacts.getArtifactPath(Artifact.engineDartSdkPath),
-        'lib',
-        'dev_compiler',
-        'kernel',
-        'amd',
-        'require.js'
-      ));
-      return Response.ok(file.readAsBytesSync(), headers: <String, String>{
-        'Content-Type': 'text/javascript',
-      });
-    } else if (request.url.path.contains('dart_sdk')) {
-      final File file = fs.file(fs.path.join(
-        artifacts.getArtifactPath(Artifact.flutterWebSdk),
-        'kernel',
-        'amd',
-        'dart_sdk.js',
-      ));
-      return Response.ok(file.readAsBytesSync(), headers: <String, String>{
-        'Content-Type': 'text/javascript',
-      });
-    } else if (request.url.path.contains('assets')) {
-      final String assetPath = request.url.path.replaceFirst('assets/', '');
-      final File file = fs.file(fs.path.join(getAssetBuildDirectory(), assetPath));
-      return Response.ok(file.readAsBytesSync());
-    }
-    return Response.notFound('');
+  static Future<Response> Function(Request request) _assetHandler(FlutterProject flutterProject) {
+    final PackageMap packageMap = PackageMap(PackageMap.globalPackagesPath);
+    return (Request request) async {
+      if (request.url.path.contains('stack_trace_mapper')) {
+        final File file = fs.file(fs.path.join(
+          artifacts.getArtifactPath(Artifact.engineDartSdkPath),
+          'lib',
+          'dev_compiler',
+          'web',
+          'dart_stack_trace_mapper.js'
+        ));
+        return Response.ok(file.readAsBytesSync(), headers: <String, String>{
+          'Content-Type': 'text/javascript',
+        });
+      } else if (request.url.path.contains('require.js')) {
+        final File file = fs.file(fs.path.join(
+          artifacts.getArtifactPath(Artifact.engineDartSdkPath),
+          'lib',
+          'dev_compiler',
+          'kernel',
+          'amd',
+          'require.js'
+        ));
+        return Response.ok(file.readAsBytesSync(), headers: <String, String>{
+          'Content-Type': 'text/javascript',
+        });
+      } else if (request.url.path.contains('dart_sdk')) {
+        final File file = fs.file(fs.path.join(
+          artifacts.getArtifactPath(Artifact.flutterWebSdk),
+          'kernel',
+          'amd',
+          'dart_sdk.js',
+        ));
+        return Response.ok(file.readAsBytesSync(), headers: <String, String>{
+          'Content-Type': 'text/javascript',
+        });
+      } else if (request.url.path.endsWith('.dart')) {
+        // This is likely a sourcemap request. The first segment is the
+        // package name, and the rest is the path to the file relative to
+        // the package uri. For example, `foo/bar.dart` would represent a
+        // file at a path like `foo/lib/bar.dart`. If there is no leading
+        // segment, then we assume it is from the current package.
+        final String packageName = request.url.pathSegments.length == 1
+          ? flutterProject.manifest.appName
+          : request.url.pathSegments.first;
+        String filePath = fs.path.joinAll(request.url.pathSegments.length == 1
+          ? request.url.pathSegments
+          : request.url.pathSegments.skip(1));
+        String packagePath = packageMap.map[packageName]?.toFilePath(windows: platform.isWindows);
+        // If the package isn't found, then we have an issue with relative
+        // paths within the main project.
+        if (packagePath == null) {
+          packagePath = packageMap.map[flutterProject.manifest.appName]
+            .toFilePath(windows: platform.isWindows);
+          filePath = request.url.path;
+        }
+        final File file = fs.file(fs.path.join(packagePath, filePath));
+        if (file.existsSync()) {
+          return Response.ok(file.readAsBytesSync());
+        }
+        return Response.notFound('');
+      } else if (request.url.path.contains('assets')) {
+        final String assetPath = request.url.path.replaceFirst('assets/', '');
+        final File file = fs.file(fs.path.join(getAssetBuildDirectory(), assetPath));
+        return Response.ok(file.readAsBytesSync());
+      }
+      return Response.notFound('');
+    };
   }
 }
 

packages/flutter_tools/test/general.shard/resident_web_runner_test.dart

@@ -74,6 +74,18 @@ void main() {
     when(mockDebugConnection.uri).thenReturn('ws://127.0.0.1/abcd/');
   }
 
+  test('profile does not supportsServiceProtocol', () => testbed.run(() {
+    final ResidentRunner profileResidentWebRunner = ResidentWebRunner(
+      MockWebDevice(),
+      flutterProject: FlutterProject.current(),
+      debuggingOptions: DebuggingOptions.enabled(BuildInfo.profile),
+      ipv6: true,
+    );
+
+    expect(profileResidentWebRunner.supportsServiceProtocol, false);
+    expect(residentWebRunner.supportsServiceProtocol, true);
+  }));
+
   test('Exits on run if application does not support the web', () => testbed.run(() async {
     fs.file('pubspec.yaml').createSync();
     final BufferLogger bufferLogger = logger;