Fix experimental incremental web compiler for Windows (#45286)

packages/flutter_tools/lib/src/resident_runner.dart

@@ -88,7 +88,9 @@ class FlutterDevice {
         fileSystemScheme: fileSystemScheme,
         targetModel: TargetModel.dartdevc,
         experimentalFlags: experimentalFlags,
-        platformDill: artifacts.getArtifactPath(Artifact.webPlatformKernelDill, mode: buildMode),
+        platformDill: fs.file(artifacts
+          .getArtifactPath(Artifact.webPlatformKernelDill, mode: buildMode))
+          .absolute.uri.toString(),
         dartDefines: dartDefines,
       );
     } else if (flutterProject.hasBuilders) {

packages/flutter_tools/lib/src/web/devfs_web.dart

@@ -12,6 +12,7 @@ import '../asset.dart';
 import '../base/common.dart';
 import '../base/file_system.dart';
 import '../base/io.dart';
+import '../base/platform.dart';
 import '../base/utils.dart';
 import '../build_info.dart';
 import '../bundle.dart';
@@ -61,6 +62,8 @@ class WebAssetServer {
   final Map<String, Uint8List> _files = <String, Uint8List>{};
   final Map<String, Uint8List> _sourcemaps = <String, Uint8List>{};
 
+  final RegExp _drivePath = RegExp(r'\/[A-Z]:\/');
+
   // handle requests for JavaScript source, dart sources maps, or asset files.
   Future<void> _handleRequest(HttpRequest request) async {
     final HttpResponse response = request.response;
@@ -79,11 +82,17 @@ class WebAssetServer {
       await response.close();
       return;
     }
+    // TODO(jonahwilliams): better path normalization in frontend_server to remove
+    // this workaround.
+    String requestPath = request.uri.path;
+    if (requestPath.startsWith(_drivePath)) {
+      requestPath = requestPath.substring(3);
+    }
 
     // If this is a JavaScript file, it must be in the in-memory cache.
     // Attempt to look up the file by URI.
-    if (_files.containsKey(request.uri.path)) {
-      final List<int> bytes = _files[request.uri.path];
+    if (_files.containsKey(requestPath)) {
+      final List<int> bytes = _files[requestPath];
       response.headers
         ..add('Content-Length', bytes.length)
         ..add('Content-Type', 'application/javascript');
@@ -93,8 +102,8 @@ class WebAssetServer {
     }
     // If this is a sourcemap file, then it might be in the in-memory cache.
     // Attempt to lookup the file by URI.
-    if (_sourcemaps.containsKey(request.uri.path)) {
-      final List<int> bytes = _sourcemaps[request.uri.path];
+    if (_sourcemaps.containsKey(requestPath)) {
+      final List<int> bytes = _sourcemaps[requestPath];
       response.headers
         ..add('Content-Length', bytes.length)
         ..add('Content-Type', 'application/json');
@@ -193,7 +202,7 @@ class WebAssetServer {
         codeStart,
         codeEnd - codeStart,
       );
-      _files[filePath] = byteView;
+      _files[_filePathToUriFragment(filePath)] = byteView;
 
       final int sourcemapStart = sourcemapOffsets[0];
       final int sourcemapEnd = sourcemapOffsets[1];
@@ -206,7 +215,7 @@ class WebAssetServer {
         sourcemapStart,
         sourcemapEnd - sourcemapStart ,
       );
-      _sourcemaps['$filePath.map'] = sourcemapView;
+      _sourcemaps['${_filePathToUriFragment(filePath)}.map'] = sourcemapView;
 
       modules.add(filePath);
     }
@@ -303,15 +312,18 @@ class WebDevFS implements DevFS {
         'dart_stack_trace_mapper.js',
       ));
       _webAssetServer.writeFile('/main.dart.js', generateBootstrapScript(
-        requireUrl: requireJS.path,
-        mapperUrl: stackTraceMapper.path,
-        entrypoint: '$mainPath.js',
+        requireUrl: _filePathToUriFragment(requireJS.path),
+        mapperUrl: _filePathToUriFragment(stackTraceMapper.path),
+        entrypoint: '${_filePathToUriFragment(mainPath)}.js',
       ));
       _webAssetServer.writeFile('/main_module.js', generateMainModule(
-        entrypoint: '$mainPath.js',
+        entrypoint: '${_filePathToUriFragment(mainPath)}.js',
       ));
       _webAssetServer.writeFile('/dart_sdk.js', dartSdk.readAsStringSync());
       _webAssetServer.writeFile('/dart_sdk.js.map', dartSdkSourcemap.readAsStringSync());
+      // TODO(jonahwilliams): refactor the asset code in this and the regular devfs to
+      // be shared.
+      await writeBundle(fs.directory(getAssetBuildDirectory()), bundle.entries);
     }
     final DateTime candidateCompileTime = DateTime.now();
     if (fullRestart) {
@@ -344,6 +356,20 @@ class WebDevFS implements DevFS {
     }
     return UpdateFSReport(success: true, syncedBytes: codeFile.lengthSync(),
       invalidatedSourcesCount: invalidatedFiles.length)
-        ..invalidatedModules = modules;
+        ..invalidatedModules = modules.map(_filePathToUriFragment).toList();
+  }
+}
+
+String _filePathToUriFragment(String path) {
+  if (platform.isWindows) {
+    final bool startWithSlash = path.startsWith('/');
+    final String partial = fs.path
+      .split(path)
+      .skip(startWithSlash ? 2 : 1).join('/');
+    if (partial.startsWith('/')) {
+      return partial;
+    }
+    return '/$partial';
   }
+  return path;
 }

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

@@ -620,8 +620,11 @@ void main() {
     expect(residentCompiler.targetModel, TargetModel.dartdevc);
     expect(residentCompiler.sdkRoot,
       artifacts.getArtifactPath(Artifact.flutterWebSdk, mode: BuildMode.debug) + '/');
-    expect(residentCompiler.platformDill,
-      artifacts.getArtifactPath(Artifact.webPlatformKernelDill, mode: BuildMode.debug));
+    expect(
+      residentCompiler.platformDill,
+      fs.file(artifacts.getArtifactPath(Artifact.webPlatformKernelDill, mode: BuildMode.debug))
+        .absolute.uri.toString(),
+    );
   }, overrides: <Type, Generator>{
     FeatureFlags: () => TestFeatureFlags(isWebIncrementalCompilerEnabled: true),
   }));

packages/flutter_tools/test/general.shard/web/devfs_web_test.dart

@@ -127,6 +127,31 @@ void main() {
     verify(headers.add('Content-Length', source.lengthSync())).called(1);
     verify(headers.add('Content-Type', 'application/javascript')).called(1);
     verify(response.add(source.readAsBytesSync())).called(1);
+  }, overrides: <Type, Generator>{
+    Platform: () => linux,
+  }));
+
+  test('serves JavaScript files from in memory cache on Windows', () => testbed.run(() async {
+    final File source = fs.file('source')
+      ..writeAsStringSync('main() {}');
+    final File sourcemap = fs.file('sourcemap')
+      ..writeAsStringSync('{}');
+    final File manifest = fs.file('manifest')
+      ..writeAsStringSync(json.encode(<String, Object>{'/C:/foo.js': <String, Object>{
+        'code': <int>[0, source.lengthSync()],
+        'sourcemap': <int>[0, 2],
+      }}));
+    webAssetServer.write(source, manifest, sourcemap);
+
+    when(request.uri).thenReturn(Uri.parse('http://foobar/C:/foo.js'));
+    requestController.add(request);
+    await closeCompleter.future;
+
+    verify(headers.add('Content-Length', source.lengthSync())).called(1);
+    verify(headers.add('Content-Type', 'application/javascript')).called(1);
+    verify(response.add(source.readAsBytesSync())).called(1);
+  }, overrides: <Type, Generator>{
+    Platform: () => windows,
   }));
 
   test('serves JavaScript files from in memory cache not from manifest', () => testbed.run(() async {