Avoid changing current directory in dart:io

Author: srujzs

dwds/test/fixtures/project.dart

@@ -22,9 +22,12 @@ class TestProject {
   late Directory _fixturesCopy;
 
   /// The top level directory in which we run the test server, e.g.
-  /// "/tmp/_testSound".
+  /// "/tmp/_testSound/".
   String get absolutePackageDirectory =>
-      p.join(_fixturesCopy.absolute.path, packageDirectory);
+      // Return it as a directory with a trailing slash.
+      Directory.fromUri(
+        _fixturesCopy.absolute.uri.resolve(packageDirectory),
+      ).uri.path;
 
   /// The directory to build and serve, e.g. "example".
   String get directoryToServe => p.split(webAssetsPath).first;
@@ -242,9 +245,18 @@ class TestProject {
     } on FileSystemException catch (_) {
       assert(Platform.isWindows);
       // On Windows, the build daemon process might still be accessing the
-      // working directory, so wait a few seconds and then try again.
-      await Future.delayed(const Duration(seconds: 5));
-      _fixturesCopy.deleteSync(recursive: true);
+      // working directory, so try again with an exponential backoff.
+      var seconds = 1;
+      final maxAttempts = 3;
+      for (var attempt = 0; attempt < maxAttempts; attempt++) {
+        try {
+          _fixturesCopy.deleteSync(recursive: true);
+          break;
+        } on FileSystemException catch (_) {
+          await Future.delayed(Duration(seconds: seconds));
+          seconds *= 2;
+        }
+      }
     }
   }
 

frontend_server_common/lib/src/asset_server.dart

@@ -26,6 +26,7 @@ class TestAssetServer implements AssetReader {
   // Fallback to "application/octet-stream" on null which
   // makes no claims as to the structure of the data.
   static const String _defaultMimeType = 'application/octet-stream';
+  final Uri _projectDirectory;
   final FileSystem _fileSystem;
   final HttpServer _httpServer;
   final Map<String, Uint8List> _files = {};
@@ -41,6 +42,7 @@ class TestAssetServer implements AssetReader {
     this._httpServer,
     this._packageUriMapper,
     this.internetAddress,
+    this._projectDirectory,
     this._fileSystem,
     this._sdkLayout,
   ) {
@@ -65,6 +67,7 @@ class TestAssetServer implements AssetReader {
   /// trace.
   static Future<TestAssetServer> start(
     String sdkDirectory,
+    Uri projectDirectory,
     FileSystem fileSystem,
     String index,
     String hostname,
@@ -75,8 +78,8 @@ class TestAssetServer implements AssetReader {
     final address = (await InternetAddress.lookup(hostname)).first;
     final httpServer = await HttpServer.bind(address, port);
     final sdkLayout = TestSdkLayout.createDefault(sdkDirectory);
-    final server = TestAssetServer(
-        index, httpServer, packageUriMapper, address, fileSystem, sdkLayout);
+    final server = TestAssetServer(index, httpServer, packageUriMapper, address,
+        projectDirectory, fileSystem, sdkLayout);
     return server;
   }
 
@@ -94,7 +97,7 @@ class TestAssetServer implements AssetReader {
     final headers = <String, String>{};
 
     if (request.url.path.endsWith('.html')) {
-      final indexFile = _fileSystem.file(index);
+      final indexFile = _fileSystem.file(_projectDirectory.resolve(index));
       if (indexFile.existsSync()) {
         headers[HttpHeaders.contentTypeHeader] = 'text/html';
         headers[HttpHeaders.contentLengthHeader] =
@@ -244,8 +247,7 @@ class TestAssetServer implements AssetReader {
     // If this is a dart file, it must be on the local file system and is
     // likely coming from a source map request. The tool doesn't currently
     // consider the case of Dart files as assets.
-    final dartFile =
-        _fileSystem.file(_fileSystem.currentDirectory.uri.resolve(path));
+    final dartFile = _fileSystem.file(_projectDirectory.resolve(path));
     if (dartFile.existsSync()) {
       return dartFile;
     }
@@ -255,7 +257,10 @@ class TestAssetServer implements AssetReader {
     // The file might have been a package file which is signaled by a
     // `/packages/<package>/<path>` request.
     if (segments.first == 'packages') {
-      final resolved = _packageUriMapper.serverPathToResolvedUri(path);
+      var resolved = _packageUriMapper.serverPathToResolvedUri(path);
+      if (resolved != null) {
+        resolved = _projectDirectory.resolveUri(resolved);
+      }
       final packageFile = _fileSystem.file(resolved);
       if (packageFile.existsSync()) {
         return packageFile;
@@ -311,7 +316,7 @@ class TestAssetServer implements AssetReader {
   }
 
   String _parseBasePathFromIndexHtml(String index) {
-    final file = _fileSystem.file(index);
+    final file = _fileSystem.file(_projectDirectory.resolve(index));
     if (!file.existsSync()) {
       throw StateError('Index file $index is not found');
     }

frontend_server_common/lib/src/devfs.dart

@@ -51,15 +51,11 @@ class WebDevFS {
 
   final TestSdkLayout sdkLayout;
   final CompilerOptions compilerOptions;
-  late final Directory _savedCurrentDirectory;
 
   Future<Uri> create() async {
-    _savedCurrentDirectory = fileSystem.currentDirectory;
-
-    fileSystem.currentDirectory = projectDirectory.toFilePath();
-
     assetServer = await TestAssetServer.start(
       sdkLayout.sdkDirectory,
+      projectDirectory,
       fileSystem,
       index,
       hostname,
@@ -71,7 +67,6 @@ class WebDevFS {
   }
 
   Future<void> dispose() {
-    fileSystem.currentDirectory = _savedCurrentDirectory;
     return assetServer.close();
   }
 
@@ -84,7 +79,8 @@ class WebDevFS {
     required bool fullRestart,
   }) async {
     final mainPath = mainUri.toFilePath();
-    final outputDirectoryPath = fileSystem.file(mainPath).parent.path;
+    final outputDirectory = fileSystem.directory(
+        fileSystem.file(projectDirectory.resolve(mainPath)).parent.path);
     final entryPoint = mainUri.toString();
 
     var prefix = '';
@@ -103,7 +99,10 @@ class WebDevFS {
       final bootstrap = '${prefix}main_module.bootstrap.js';
 
       assetServer.writeFile(
-          entryPoint, fileSystem.file(mainPath).readAsStringSync());
+          entryPoint,
+          fileSystem
+              .file(projectDirectory.resolve(mainPath))
+              .readAsStringSync());
       assetServer.writeFile(stackMapper, stackTraceMapper.readAsStringSync());
 
       switch (ddcModuleFormat) {
@@ -199,14 +198,13 @@ class WebDevFS {
     File metadataFile;
     List<String> modules;
     try {
-      final parentDirectory = fileSystem.directory(outputDirectoryPath);
       codeFile =
-          parentDirectory.childFile('${compilerOutput.outputFilename}.sources');
+          outputDirectory.childFile('${compilerOutput.outputFilename}.sources');
       manifestFile =
-          parentDirectory.childFile('${compilerOutput.outputFilename}.json');
+          outputDirectory.childFile('${compilerOutput.outputFilename}.json');
       sourcemapFile =
-          parentDirectory.childFile('${compilerOutput.outputFilename}.map');
-      metadataFile = parentDirectory
+          outputDirectory.childFile('${compilerOutput.outputFilename}.map');
+      metadataFile = outputDirectory
           .childFile('${compilerOutput.outputFilename}.metadata');
       modules = assetServer.write(
           codeFile, manifestFile, sourcemapFile, metadataFile);

frontend_server_common/lib/src/frontend_server_client.dart

@@ -402,7 +402,6 @@ class ResidentCompiler {
       if (compilerOptions.moduleFormat == ModuleFormat.ddc)
         '--dartdevc-module-format=ddc'
     ];
-
     _logger.info(args.join(' '));
     final workingDirectory = projectDirectory.toFilePath();
     _server = await Process.start(sdkLayout.dartAotRuntimePath, args,
@@ -657,7 +656,7 @@ String _toMultiRootPath(
   for (final fileSystemRoot in fileSystemRoots) {
     final rootPath = fileSystemRoot.toFilePath(windows: Platform.isWindows);
     if (filePath.startsWith(rootPath)) {
-      return '$scheme://${filePath.substring(rootPath.length)}';
+      return '$scheme:///${filePath.substring(rootPath.length)}';
     }
   }
   return fileUri.toString();

test_common/lib/utilities.dart

@@ -12,12 +12,10 @@ const fixturesDirName = 'fixtures';
 
 const newDdcTypeSystemVersion = '3.3.0-242.0.dev';
 
-final _currentDirectory = p.current;
-
 /// The path to the webdev directory in the local machine, e.g.
 /// '/workstation/webdev'.
 String get webdevPath {
-  final pathParts = p.split(_currentDirectory);
+  final pathParts = p.split(p.current);
   assert(pathParts.contains(webdevDirName));
   return p.joinAll(
     pathParts.sublist(0, pathParts.lastIndexOf(webdevDirName) + 1),