diff --git a/dwds/test/build_daemon_breakpoint_test.dart b/dwds/test/build_daemon_breakpoint_test.dart
index 21a71d372..8dd6fe192 100644
--- a/dwds/test/build_daemon_breakpoint_test.dart
+++ b/dwds/test/build_daemon_breakpoint_test.dart
@@ -8,18 +8,18 @@ import 'dart:async';
 
 import 'package:dwds/src/connections/debug_connection.dart';
 import 'package:dwds/src/services/chrome_proxy_service.dart';
-import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:vm_service/vm_service.dart';
 import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
 
 import 'fixtures/context.dart';
 
-final context = TestContext(
-    directory: p.join('..', 'fixtures', '_testPackageSound'),
-    entry: p.join('..', 'fixtures', '_testPackageSound', 'web', 'main.dart'),
-    path: 'index.html',
-    pathToServe: 'web');
+final context = TestContext.withSoundNullSafety(
+  packageName: '_testPackageSound',
+  webAssetsPath: 'web',
+  dartEntryFileName: 'main.dart',
+  htmlEntryFileName: 'index.html',
+);
 
 ChromeProxyService get service =>
     fetchChromeProxyService(context.debugConnection);
diff --git a/dwds/test/build_daemon_callstack_test.dart b/dwds/test/build_daemon_callstack_test.dart
index 0e51f75c2..f3ee816ef 100644
--- a/dwds/test/build_daemon_callstack_test.dart
+++ b/dwds/test/build_daemon_callstack_test.dart
@@ -8,7 +8,6 @@ import 'dart:async';
 
 import 'package:dwds/src/connections/debug_connection.dart';
 import 'package:dwds/src/services/chrome_proxy_service.dart';
-import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:vm_service/vm_service.dart';
 import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
@@ -18,20 +17,18 @@ import 'fixtures/logging.dart';
 import 'utils/version_compatibility.dart';
 
 class TestSetup {
-  static final contextUnsound = TestContext(
-    directory: p.join('..', 'fixtures', '_testPackage'),
-    entry: p.join('..', 'fixtures', '_testPackage', 'web', 'main.dart'),
-    path: 'index.html',
-    pathToServe: 'web',
-    nullSafety: NullSafety.weak,
+  static final contextUnsound = TestContext.withWeakNullSafety(
+    packageName: '_testPackage',
+    webAssetsPath: 'web',
+    dartEntryFileName: 'main.dart',
+    htmlEntryFileName: 'index.html',
   );
 
-  static final contextSound = TestContext(
-    directory: p.join('..', 'fixtures', '_testPackageSound'),
-    entry: p.join('..', 'fixtures', '_testPackageSound', 'web', 'main.dart'),
-    path: 'index.html',
-    pathToServe: 'web',
-    nullSafety: NullSafety.sound,
+  static final contextSound = TestContext.withSoundNullSafety(
+    packageName: '_testPackageSound',
+    webAssetsPath: 'web',
+    dartEntryFileName: 'main.dart',
+    htmlEntryFileName: 'index.html',
   );
 
   TestContext context;
diff --git a/dwds/test/chrome_proxy_service_test.dart b/dwds/test/chrome_proxy_service_test.dart
index b9f86a9df..2054485cc 100644
--- a/dwds/test/chrome_proxy_service_test.dart
+++ b/dwds/test/chrome_proxy_service_test.dart
@@ -21,7 +21,7 @@ import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
 import 'fixtures/context.dart';
 import 'fixtures/logging.dart';
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 
 ChromeProxyService get service =>
     fetchChromeProxyService(context.debugConnection);
diff --git a/dwds/test/dart_uri_file_uri_test.dart b/dwds/test/dart_uri_file_uri_test.dart
index f19c3858f..346165ec2 100644
--- a/dwds/test/dart_uri_file_uri_test.dart
+++ b/dwds/test/dart_uri_file_uri_test.dart
@@ -13,21 +13,19 @@ import 'fixtures/context.dart';
 import 'fixtures/utilities.dart';
 import 'utils/version_compatibility.dart';
 
-final context = TestContext(
-  directory: p.join('..', 'fixtures', '_testPackage'),
-  entry: p.join('..', 'fixtures', '_testPackage', 'web', 'main.dart'),
-  path: 'index.html',
-  pathToServe: 'web',
-  nullSafety: NullSafety.weak,
+final context = TestContext.withWeakNullSafety(
+  packageName: '_testPackage',
+  webAssetsPath: 'web',
+  dartEntryFileName: 'main.dart',
+  htmlEntryFileName: 'index.html',
 );
 
 /// The directory for the general _test package.
-final testDir = absolutePath(pathFromDwds: p.join('..', 'fixtures', '_test'));
+final testDir = absolutePath(pathFromFixtures: p.join('_test'));
 
 /// The directory for the _testPackage package (contained within dwds), which
 /// imports _test.
-final testPackageDir =
-    absolutePath(pathFromDwds: p.join('..', 'fixtures', '_testPackage'));
+final testPackageDir = absolutePath(pathFromFixtures: p.join('_testPackage'));
 
 // This tests converting file Uris into our internal paths.
 //
diff --git a/dwds/test/debug_extension_test.dart b/dwds/test/debug_extension_test.dart
index eea611621..97e63d783 100644
--- a/dwds/test/debug_extension_test.dart
+++ b/dwds/test/debug_extension_test.dart
@@ -29,7 +29,7 @@ import 'fixtures/utilities.dart';
 // Remove the key before pushing code to GitHub.
 // See go/extension-identification.
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 
 void main() async {
   Future<void> waitForDartDevToolsWithRetry({
@@ -203,7 +203,7 @@ void main() async {
   }
 
   group('With encoding', () {
-    final context = TestContext();
+    final context = TestContext.withSoundNullSafety();
     setUp(() async {
       await context.setUp(
           enableDebugExtension: true,
@@ -224,7 +224,7 @@ void main() async {
   });
 
   group('With "any" hostname', () {
-    final context = TestContext();
+    final context = TestContext.withSoundNullSafety();
     final uriPattern = RegExp(r'dartExtensionUri = "([^"]+)";');
 
     setUp(() async {
diff --git a/dwds/test/debug_service_test.dart b/dwds/test/debug_service_test.dart
index 6ae1cd0b5..e165c1f1f 100644
--- a/dwds/test/debug_service_test.dart
+++ b/dwds/test/debug_service_test.dart
@@ -12,7 +12,7 @@ import 'package:test/test.dart';
 
 import 'fixtures/context.dart';
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 
 void main() {
   setUpAll(() async {
diff --git a/dwds/test/debugger_test.dart b/dwds/test/debugger_test.dart
index de93f2517..4585404a8 100644
--- a/dwds/test/debugger_test.dart
+++ b/dwds/test/debugger_test.dart
@@ -22,7 +22,7 @@ import 'fixtures/context.dart';
 import 'fixtures/debugger_data.dart';
 import 'fixtures/fakes.dart';
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 late AppInspector inspector;
 late Debugger debugger;
 late FakeWebkitDebugger webkitDebugger;
diff --git a/dwds/test/devtools_test.dart b/dwds/test/devtools_test.dart
index 13a0f29e0..66422ce7f 100644
--- a/dwds/test/devtools_test.dart
+++ b/dwds/test/devtools_test.dart
@@ -13,9 +13,7 @@ import 'package:webdriver/io.dart';
 
 import 'fixtures/context.dart';
 
-final context = TestContext(
-  path: 'append_body/index.html',
-);
+final context = TestContext.withSoundNullSafety();
 
 Future<void> _waitForPageReady(TestContext context) async {
   var attempt = 100;
diff --git a/dwds/test/evaluate_circular_common.dart b/dwds/test/evaluate_circular_common.dart
index 2184559c6..87bc97370 100644
--- a/dwds/test/evaluate_circular_common.dart
+++ b/dwds/test/evaluate_circular_common.dart
@@ -8,7 +8,6 @@ import 'dart:async';
 
 import 'package:dwds/src/connections/debug_connection.dart';
 import 'package:dwds/src/services/chrome_proxy_service.dart';
-import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:vm_service/vm_service.dart';
 import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
@@ -17,21 +16,21 @@ import 'fixtures/context.dart';
 import 'fixtures/logging.dart';
 
 class TestSetup {
-  static TestContext createContext(
-          String index, String packageRoot, NullSafety nullSafety) =>
-      TestContext(
-        directory: p.join('..', 'fixtures', packageRoot),
-        entry: p.join('..', 'fixtures', packageRoot, 'web', 'main.dart'),
-        path: index,
-        pathToServe: 'web',
-        nullSafety: nullSafety,
-      );
-
   static TestContext contextUnsound(String index) =>
-      createContext(index, '_testCircular2', NullSafety.weak);
+      TestContext.withWeakNullSafety(
+        packageName: '_testCircular2',
+        webAssetsPath: 'web',
+        dartEntryFileName: 'main.dart',
+        htmlEntryFileName: index,
+      );
 
   static TestContext contextSound(String index) =>
-      createContext(index, '_testCircular2Sound', NullSafety.sound);
+      TestContext.withSoundNullSafety(
+        packageName: '_testCircular2Sound',
+        webAssetsPath: 'web',
+        dartEntryFileName: 'main.dart',
+        htmlEntryFileName: index,
+      );
 
   TestContext context;
 
diff --git a/dwds/test/evaluate_common.dart b/dwds/test/evaluate_common.dart
index a6dce398f..41b8cb51f 100644
--- a/dwds/test/evaluate_common.dart
+++ b/dwds/test/evaluate_common.dart
@@ -8,7 +8,6 @@ import 'dart:async';
 
 import 'package:dwds/src/connections/debug_connection.dart';
 import 'package:dwds/src/services/chrome_proxy_service.dart';
-import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:vm_service/vm_service.dart';
 import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
@@ -17,20 +16,21 @@ import 'fixtures/context.dart';
 import 'fixtures/logging.dart';
 
 class TestSetup {
-  static TestContext createContext(
-          String index, String packageRoot, NullSafety nullSafety) =>
-      TestContext(
-          directory: p.join('..', 'fixtures', packageRoot),
-          entry: p.join('..', 'fixtures', packageRoot, 'web', 'main.dart'),
-          path: index,
-          pathToServe: 'web',
-          nullSafety: nullSafety);
-
   static TestContext contextUnsound(String index) =>
-      createContext(index, '_testPackage', NullSafety.weak);
+      TestContext.withWeakNullSafety(
+        packageName: '_testPackage',
+        webAssetsPath: 'web',
+        dartEntryFileName: 'main.dart',
+        htmlEntryFileName: index,
+      );
 
   static TestContext contextSound(String index) =>
-      createContext(index, '_testPackageSound', NullSafety.sound);
+      TestContext.withSoundNullSafety(
+        packageName: '_testPackageSound',
+        webAssetsPath: 'web',
+        dartEntryFileName: 'main.dart',
+        htmlEntryFileName: index,
+      );
 
   TestContext context;
 
diff --git a/dwds/test/events_test.dart b/dwds/test/events_test.dart
index eaa194aa4..51f1eb9f5 100644
--- a/dwds/test/events_test.dart
+++ b/dwds/test/events_test.dart
@@ -23,7 +23,7 @@ ChromeProxyService get service =>
 
 WipConnection get tabConnection => context.tabConnection;
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 
 void main() {
   group('serve requests', () {
diff --git a/dwds/test/fixtures/context.dart b/dwds/test/fixtures/context.dart
index 94ed72905..ff62190ad 100644
--- a/dwds/test/fixtures/context.dart
+++ b/dwds/test/fixtures/context.dart
@@ -55,6 +55,46 @@ enum IndexBaseMode { noBase, base }
 enum NullSafety { weak, sound }
 
 class TestContext {
+  final String packageName;
+  final String webAssetsPath;
+  final String dartEntryFileName;
+  final String htmlEntryFileName;
+  final NullSafety nullSafety;
+
+  /// Top level directory in which we run the test server, e.g.
+  /// "/workstation/webdev/fixtures/_testSound".
+  String get workingDirectory => absolutePath(pathFromFixtures: packageName);
+
+  /// The directory to build and serve, e.g. "example".
+  String get directoryToServe => p.split(webAssetsPath).first;
+
+  /// The path to the HTML file to serve, relative to the [directoryToServe],
+  /// e.g. "hello_world/index.html".
+  String get filePathToServe {
+    final pathParts = p.split(webAssetsPath).where(
+          (pathPart) => pathPart != directoryToServe,
+        );
+    return webCompatiblePath([...pathParts, htmlEntryFileName]);
+  }
+
+  /// The entry file is the Dart entry file, e.g,
+  /// "/workstation/webdev/fixtures/_testSound/example/hello_world/main.dart":
+  File get _entryFile => File(
+        absolutePath(
+          pathFromFixtures: p.joinAll(
+            [packageName, webAssetsPath, dartEntryFileName],
+          ),
+        ),
+      );
+
+  /// The contents of the Dart entry file:
+  String get _entryContents => _entryFile.readAsStringSync();
+
+  /// The URI for the package_config.json is located in:
+  /// <project directory>/.dart_tool/package_config
+  Uri get _packageConfigFile =>
+      p.toUri(p.join(workingDirectory, '.dart_tool', 'package_config.json'));
+
   String get appUrl => _appUrl!;
   late String? _appUrl;
 
@@ -96,58 +136,54 @@ class TestContext {
   late WipConnection extensionConnection;
   late AppConnection appConnection;
   late DebugConnection debugConnection;
-  late File _entryFile;
-  late Uri _packageConfigFile;
-  late Uri _projectDirectory;
-  late String _entryContents;
 
   final _logger = logging.Logger('Context');
 
-  /// Top level directory in which we run the test server..
-  late String workingDirectory;
-
-  /// The path to build and serve.
-  String pathToServe;
-
-  /// The path part of the application URL.
-  String path;
-
-  NullSafety nullSafety;
-
-  TestContext({
-    String? directory,
-    String? entry,
-    this.nullSafety = NullSafety.sound,
-    this.path = 'hello_world/index.html',
-    this.pathToServe = 'example',
+  TestContext.withSoundNullSafety({
+    String packageName = '_testSound',
+    String webAssetsPath = 'example/hello_world',
+    String dartEntryFileName = 'main.dart',
+    String htmlEntryFileName = 'index.html',
+  }) : this._(
+          nullSafety: NullSafety.sound,
+          packageName: packageName,
+          webAssetsPath: webAssetsPath,
+          dartEntryFileName: dartEntryFileName,
+          htmlEntryFileName: htmlEntryFileName,
+        );
+
+  TestContext.withWeakNullSafety({
+    String packageName = '_test',
+    String webAssetsPath = 'example/hello_world',
+    String dartEntryFileName = 'main.dart',
+    String htmlEntryFileName = 'index.html',
+  }) : this._(
+          nullSafety: NullSafety.weak,
+          packageName: packageName,
+          webAssetsPath: webAssetsPath,
+          dartEntryFileName: dartEntryFileName,
+          htmlEntryFileName: htmlEntryFileName,
+        );
+
+  TestContext._({
+    required this.packageName,
+    required this.webAssetsPath,
+    required this.dartEntryFileName,
+    required this.htmlEntryFileName,
+    required this.nullSafety,
   }) {
-    final pathParts = p.split(p.current);
-    assert(pathParts.contains('webdev'));
-    final defaultPackage =
-        nullSafety == NullSafety.sound ? '_testSound' : '_test';
-    final defaultDirectory = p.join('..', 'fixtures', defaultPackage);
-    final defaultEntry = p.join('..', 'fixtures', defaultPackage, 'example',
-        'hello_world', 'main.dart');
-
-    workingDirectory =
-        absolutePath(pathFromDwds: directory ?? defaultDirectory);
+    // Verify that the test fixtures package matches the null-safety mode:
+    final isSoundPackage = packageName.toLowerCase().contains('sound');
+    assert(nullSafety == NullSafety.sound ? isSoundPackage : !isSoundPackage);
+    // Verify that the web assets path has no starting slash:
+    assert(!webAssetsPath.startsWith('/'));
 
     DartUri.currentDirectory = workingDirectory;
 
-    // package_config.json is located in <project directory>/.dart_tool/package_config
-    _projectDirectory = p.toUri(workingDirectory);
-    _packageConfigFile =
-        p.toUri(p.join(workingDirectory, '.dart_tool/package_config.json'));
-
-    final entryFilePath = absolutePath(pathFromDwds: entry ?? defaultEntry);
-
-    _logger.info('Serving: $pathToServe/$path');
-    _logger.info('Project: $_projectDirectory');
+    _logger.info('Serving: $directoryToServe/$filePathToServe');
+    _logger.info('Project: $workingDirectory');
     _logger.info('Packages: $_packageConfigFile');
-    _logger.info('Entry: $entryFilePath');
-
-    _entryFile = File(entryFilePath);
-    _entryContents = _entryFile.readAsStringSync();
+    _logger.info('Entry: ${_entryFile.path}');
   }
 
   Future<void> setUp({
@@ -252,7 +288,7 @@ class TestContext {
                   record.stackTrace);
             });
             daemonClient.registerBuildTarget(
-                DefaultBuildTarget((b) => b..target = pathToServe));
+                DefaultBuildTarget((b) => b..target = directoryToServe));
             daemonClient.startBuild();
 
             await daemonClient.buildResults
@@ -262,10 +298,10 @@ class TestContext {
 
             final assetServerPort = daemonPort(workingDirectory);
             _assetHandler = proxyHandler(
-                'http://localhost:$assetServerPort/$pathToServe/',
+                'http://localhost:$assetServerPort/$directoryToServe/',
                 client: client);
             assetReader =
-                ProxyServerAssetReader(assetServerPort, root: pathToServe);
+                ProxyServerAssetReader(assetServerPort, root: directoryToServe);
 
             if (enableExpressionEvaluation) {
               ddcService = ExpressionCompilerService(
@@ -288,11 +324,9 @@ class TestContext {
           break;
         case CompilationMode.frontendServer:
           {
-            _logger.warning('Index: $path');
-
-            final entry = p.toUri(_entryFile.path
-                .substring(_projectDirectory.toFilePath().length + 1));
+            _logger.warning('Index: $filePathToServe');
 
+            final entry = p.toUri(p.join(webAssetsPath, dartEntryFileName));
             final fileSystem = LocalFileSystem();
             final packageUriMapper = await PackageUriMapper.create(
               fileSystem,
@@ -303,10 +337,10 @@ class TestContext {
             _webRunner = ResidentWebRunner(
               entry,
               urlEncoder,
-              _projectDirectory,
+              p.toUri(workingDirectory),
               _packageConfigFile,
               packageUriMapper,
-              [_projectDirectory],
+              [p.toUri(workingDirectory)],
               'org-dartlang-app',
               outputDir.path,
               nullSafety == NullSafety.sound,
@@ -315,7 +349,7 @@ class TestContext {
 
             final assetServerPort = await findUnusedPort();
             await webRunner.run(fileSystem, hostname, assetServerPort,
-                p.join(pathToServe, path));
+                p.join(directoryToServe, filePathToServe));
 
             if (enableExpressionEvaluation) {
               expressionCompiler = webRunner.expressionCompiler;
@@ -376,7 +410,7 @@ class TestContext {
         assetHandler,
         assetReader,
         requireStrategy,
-        pathToServe,
+        directoryToServe,
         buildResults,
         () async => connection,
         serveDevTools,
@@ -393,8 +427,8 @@ class TestContext {
       );
 
       _appUrl = basePath.isEmpty
-          ? 'http://localhost:$port/$path'
-          : 'http://localhost:$port/$basePath/$path';
+          ? 'http://localhost:$port/$filePathToServe'
+          : 'http://localhost:$port/$basePath/$filePathToServe';
 
       if (launchChrome) {
         await _webDriver?.get(appUrl);
diff --git a/dwds/test/fixtures/utilities.dart b/dwds/test/fixtures/utilities.dart
index 2f1366a23..dacb24412 100644
--- a/dwds/test/fixtures/utilities.dart
+++ b/dwds/test/fixtures/utilities.dart
@@ -11,26 +11,61 @@ import 'package:path/path.dart' as p;
 
 const webdevDirName = 'webdev';
 const dwdsDirName = 'dwds';
+const fixturesDirName = 'fixtures';
 
-/// The path to the DWDS directory in the local machine, e.g.
-/// "/workstation/webdev/dwds".
-String get dwdsPath {
+/// The path to the webdev directory in the local machine, e.g.
+/// '/workstation/webdev'.
+String get webdevPath {
   final pathParts = p.split(p.current);
   // We expect all tests to be run from the webdev mono-repo:
   assert(pathParts.contains(webdevDirName));
   return p.joinAll(
-    [
-      ...pathParts.sublist(0, pathParts.lastIndexOf(webdevDirName) + 1),
-      dwdsDirName,
-    ],
+    pathParts.sublist(0, pathParts.lastIndexOf(webdevDirName) + 1),
   );
 }
 
-/// Given a [pathFromDwds], e.g. '../fixtures/_test', returns its absolute
-/// path, e.g. '/workstation/webdev/fixtures/_test'.
-String absolutePath({required String pathFromDwds}) => p.normalize(
-      p.join(dwdsPath, pathFromDwds),
-    );
+/// The path to the DWDS directory in the local machine, e.g.
+/// '/workstation/webdev/dwds'.
+String get dwdsPath {
+  return p.join(webdevPath, dwdsDirName);
+}
+
+/// The path to the fixtures directory in the local machine, e.g.
+/// '/workstation/webdev/fixtures'.
+String get fixturesPath {
+  return p.join(webdevPath, fixturesDirName);
+}
+
+// Creates a path compatible for web.
+String webCompatiblePath(List<String> pathParts) {
+  // Note: Replacing "\" with "/" is necessary because `joinAll` uses "\" if
+  // the platform is Windows. However, only "/" is expected by the browser.
+  return p.joinAll([...pathParts]).replaceAll('\\', '/');
+}
+
+/// Expects one of [pathFromWebdev], [pathFromDwds] or [pathFromFixtures]  to be
+/// provided. Returns the absolute path in the local machine to that path, e.g.
+///   absolutePath(pathFromFixtures: '_test/example') ->
+///   '/workstation/webdev/fixtures/_test/example'
+String absolutePath({
+  String? pathFromWebdev,
+  String? pathFromDwds,
+  String? pathFromFixtures,
+}) {
+  if (pathFromWebdev != null) {
+    assert(pathFromDwds == null && pathFromFixtures == null);
+    return p.normalize(p.join(webdevPath, pathFromWebdev));
+  }
+  if (pathFromDwds != null) {
+    assert(pathFromFixtures == null);
+    return p.normalize(p.join(dwdsPath, pathFromDwds));
+  }
+  if (pathFromFixtures != null) {
+    assert(pathFromDwds == null && pathFromWebdev == null);
+    return p.normalize(p.join(fixturesPath, pathFromFixtures));
+  }
+  throw Exception('Expected a path parameter.');
+}
 
 /// Connects to the `build_runner` daemon.
 Future<BuildDaemonClient> connectClient(String workingDirectory,
diff --git a/dwds/test/frontend_server_breakpoint_test.dart b/dwds/test/frontend_server_breakpoint_test.dart
index 2df12d982..ba190c46d 100644
--- a/dwds/test/frontend_server_breakpoint_test.dart
+++ b/dwds/test/frontend_server_breakpoint_test.dart
@@ -8,7 +8,6 @@ import 'dart:async';
 
 import 'package:dwds/src/connections/debug_connection.dart';
 import 'package:dwds/src/services/chrome_proxy_service.dart';
-import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:vm_service/vm_service.dart';
 import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
@@ -17,12 +16,11 @@ import 'fixtures/context.dart';
 import 'fixtures/logging.dart';
 import 'utils/version_compatibility.dart';
 
-final context = TestContext(
-  directory: p.join('..', 'fixtures', '_testPackage'),
-  entry: p.join('..', 'fixtures', '_testPackage', 'web', 'main.dart'),
-  path: 'index.html',
-  pathToServe: 'web',
-  nullSafety: NullSafety.weak,
+final context = TestContext.withWeakNullSafety(
+  packageName: '_testPackage',
+  webAssetsPath: 'web',
+  dartEntryFileName: 'main.dart',
+  htmlEntryFileName: 'index.html',
 );
 
 ChromeProxyService get service =>
diff --git a/dwds/test/frontend_server_callstack_test.dart b/dwds/test/frontend_server_callstack_test.dart
index b8ccf36ed..e1cb27c9a 100644
--- a/dwds/test/frontend_server_callstack_test.dart
+++ b/dwds/test/frontend_server_callstack_test.dart
@@ -8,7 +8,6 @@ import 'dart:async';
 
 import 'package:dwds/src/connections/debug_connection.dart';
 import 'package:dwds/src/services/chrome_proxy_service.dart';
-import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:vm_service/vm_service.dart';
 import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
@@ -18,20 +17,18 @@ import 'fixtures/logging.dart';
 import 'utils/version_compatibility.dart';
 
 class TestSetup {
-  static final contextUnsound = TestContext(
-    directory: p.join('..', 'fixtures', '_testPackage'),
-    entry: p.join('..', 'fixtures', '_testPackage', 'web', 'main.dart'),
-    path: 'index.html',
-    pathToServe: 'web',
-    nullSafety: NullSafety.weak,
+  static final contextUnsound = TestContext.withWeakNullSafety(
+    packageName: '_testPackage',
+    webAssetsPath: 'web',
+    dartEntryFileName: 'main.dart',
+    htmlEntryFileName: 'index.html',
   );
 
-  static final contextSound = TestContext(
-    directory: p.join('..', 'fixtures', '_testPackageSound'),
-    entry: p.join('..', 'fixtures', '_testPackageSound', 'web', 'main.dart'),
-    path: 'index.html',
-    pathToServe: 'web',
-    nullSafety: NullSafety.sound,
+  static final contextSound = TestContext.withSoundNullSafety(
+    packageName: '_testPackageSound',
+    webAssetsPath: 'web',
+    dartEntryFileName: 'main.dart',
+    htmlEntryFileName: 'index.html',
   );
 
   TestContext context;
diff --git a/dwds/test/handlers/asset_handler_test.dart b/dwds/test/handlers/asset_handler_test.dart
index 82043f06e..7cb468193 100644
--- a/dwds/test/handlers/asset_handler_test.dart
+++ b/dwds/test/handlers/asset_handler_test.dart
@@ -12,7 +12,7 @@ import '../fixtures/logging.dart';
 
 void main() {
   group('Asset handler', () {
-    final context = TestContext();
+    final context = TestContext.withSoundNullSafety();
 
     setUpAll(() async {
       setCurrentLogWriter();
diff --git a/dwds/test/inspector_test.dart b/dwds/test/inspector_test.dart
index 31fead67b..10100f93b 100644
--- a/dwds/test/inspector_test.dart
+++ b/dwds/test/inspector_test.dart
@@ -11,23 +11,18 @@ import 'package:dwds/src/debugging/debugger.dart';
 import 'package:dwds/src/debugging/inspector.dart';
 import 'package:dwds/src/loaders/strategy.dart';
 import 'package:dwds/src/utilities/conversions.dart';
-import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:vm_service/vm_service.dart';
 import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
 
 import 'fixtures/context.dart';
+import 'fixtures/utilities.dart';
 
-final context = TestContext(
-    path: 'scopes/scopes.html',
-    entry: p.join(
-      '..',
-      'fixtures',
-      '_testSound',
-      'example',
-      'scopes',
-      'scopes_main.dart',
-    ));
+final context = TestContext.withSoundNullSafety(
+  webAssetsPath: webCompatiblePath(['example', 'scopes']),
+  dartEntryFileName: 'main.dart',
+  htmlEntryFileName: 'scopes.html',
+);
 
 WipConnection get tabConnection => context.tabConnection;
 
@@ -46,11 +41,11 @@ void main() {
     await context.tearDown();
   });
 
-  final url = 'org-dartlang-app:///example/scopes/scopes_main.dart';
+  final url = 'org-dartlang-app:///example/scopes/main.dart';
 
   /// A convenient way to get a library variable without boilerplate.
   String libraryVariableExpression(String variable) =>
-      '${globalLoadStrategy.loadModuleSnippet}("dart_sdk").dart.getModuleLibraries("example/scopes/scopes_main")["$url"]["$variable"];';
+      '${globalLoadStrategy.loadModuleSnippet}("dart_sdk").dart.getModuleLibraries("example/scopes/main")["$url"]["$variable"];';
 
   Future<RemoteObject> libraryPublicFinal() =>
       inspector.jsEvaluate(libraryVariableExpression('libraryPublicFinal'));
@@ -236,27 +231,27 @@ void main() {
 }
 
 final jsMultiLineExceptionWithStackTrace = '''
-Error: Assertion failed: org-dartlang-app:///example/scopes/scopes_main.dart:4:11
+Error: Assertion failed: org-dartlang-app:///example/scopes/main.dart:4:11
 false
 "THIS IS THE ASSERT MESSAGE"
-    at Object.assertFailed (org-dartlang-app:///example/scopes/scopes_main.dart.js:5297:15)
+    at Object.assertFailed (org-dartlang-app:///example/scopes/main.dart.js:5297:15)
 ''';
 
 final formattedMultiLineExceptionWithStackTrace = '''
-Error: Assertion failed: org-dartlang-app:///example/scopes/scopes_main.dart:4:11
+Error: Assertion failed: org-dartlang-app:///example/scopes/main.dart:4:11
 false
 "THIS IS THE ASSERT MESSAGE"
-org-dartlang-app:///example/scopes/scopes_main.dart.js 5297:15  assertFailed
+org-dartlang-app:///example/scopes/main.dart.js 5297:15  assertFailed
 ''';
 
 final jsMultiLineExceptionNoStackTrace = '''
-Error: Assertion failed: org-dartlang-app:///example/scopes/scopes_main.dart:4:11
+Error: Assertion failed: org-dartlang-app:///example/scopes/main.dart:4:11
 false
 "THIS IS THE ASSERT MESSAGE"
 ''';
 
 final formattedMultiLineExceptionNoStackTrace = '''
-Error: Assertion failed: org-dartlang-app:///example/scopes/scopes_main.dart:4:11
+Error: Assertion failed: org-dartlang-app:///example/scopes/main.dart:4:11
 false
 "THIS IS THE ASSERT MESSAGE"
 ''';
diff --git a/dwds/test/instance_test.dart b/dwds/test/instance_test.dart
index f69c763c9..c5f279703 100644
--- a/dwds/test/instance_test.dart
+++ b/dwds/test/instance_test.dart
@@ -9,23 +9,18 @@ import 'package:dwds/src/connections/debug_connection.dart';
 import 'package:dwds/src/debugging/debugger.dart';
 import 'package:dwds/src/debugging/inspector.dart';
 import 'package:dwds/src/loaders/strategy.dart';
-import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:vm_service/vm_service.dart';
 import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
 
 import 'fixtures/context.dart';
+import 'fixtures/utilities.dart';
 
-final context = TestContext(
-    path: 'scopes/scopes.html',
-    entry: p.join(
-      '..',
-      'fixtures',
-      '_testSound',
-      'example',
-      'scopes',
-      'scopes_main.dart',
-    ));
+final context = TestContext.withSoundNullSafety(
+  webAssetsPath: webCompatiblePath(['example', 'scopes']),
+  dartEntryFileName: 'main.dart',
+  htmlEntryFileName: 'scopes.html',
+);
 
 WipConnection get tabConnection => context.tabConnection;
 
@@ -44,10 +39,10 @@ void main() {
     await context.tearDown();
   });
 
-  final url = 'org-dartlang-app:///example/scopes/scopes_main.dart';
+  final url = 'org-dartlang-app:///example/scopes/main.dart';
 
   String libraryVariableExpression(String variable) =>
-      '${globalLoadStrategy.loadModuleSnippet}("dart_sdk").dart.getModuleLibraries("example/scopes/scopes_main")'
+      '${globalLoadStrategy.loadModuleSnippet}("dart_sdk").dart.getModuleLibraries("example/scopes/main")'
       '["$url"]["$variable"];';
 
   /// A reference to the the variable `libraryPublicFinal`, an instance of
@@ -91,7 +86,7 @@ void main() {
       expect(classRef.name, 'MyTestClass<dynamic>');
       expect(
           classRef.id,
-          'classes|org-dartlang-app:///example/scopes/scopes_main.dart'
+          'classes|org-dartlang-app:///example/scopes/main.dart'
           '|MyTestClass<dynamic>');
     });
 
diff --git a/dwds/test/listviews_test.dart b/dwds/test/listviews_test.dart
index b60aa1415..db3c5b1fd 100644
--- a/dwds/test/listviews_test.dart
+++ b/dwds/test/listviews_test.dart
@@ -8,7 +8,7 @@ import 'package:test/test.dart';
 
 import 'fixtures/context.dart';
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 
 void main() {
   setUpAll(() async {
diff --git a/dwds/test/package_uri_mapper_test.dart b/dwds/test/package_uri_mapper_test.dart
index 69fd83cbf..9bf1f18bc 100644
--- a/dwds/test/package_uri_mapper_test.dart
+++ b/dwds/test/package_uri_mapper_test.dart
@@ -31,12 +31,8 @@ void main() {
       final resolvedPath =
           '/webdev/fixtures/_testPackageSound/lib/test_library.dart';
 
-      final testPackageSoundPath = absolutePath(
-          pathFromDwds: p.join(
-        '..',
-        'fixtures',
-        '_testPackageSound',
-      ));
+      final testPackageSoundPath =
+          absolutePath(pathFromFixtures: '_testPackageSound');
 
       final packageConfigFile = Uri.file(p.join(
         testPackageSoundPath,
diff --git a/dwds/test/puppeteer/extension_test.dart b/dwds/test/puppeteer/extension_test.dart
index 66a62b15d..c54bc237d 100644
--- a/dwds/test/puppeteer/extension_test.dart
+++ b/dwds/test/puppeteer/extension_test.dart
@@ -24,7 +24,7 @@ import '../../debug_extension_mv3/web/data_types.dart';
 import '../fixtures/context.dart';
 import 'test_utils.dart';
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 
 enum Panel { debugger, inspector }
 
diff --git a/dwds/test/puppeteer/lifeline_test.dart b/dwds/test/puppeteer/lifeline_test.dart
index 600db189b..bd920dcc6 100644
--- a/dwds/test/puppeteer/lifeline_test.dart
+++ b/dwds/test/puppeteer/lifeline_test.dart
@@ -12,7 +12,7 @@ import 'package:test/test.dart';
 import '../fixtures/context.dart';
 import 'test_utils.dart';
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 
 void main() async {
   late Worker worker;
diff --git a/dwds/test/readers/frontend_server_asset_reader_test.dart b/dwds/test/readers/frontend_server_asset_reader_test.dart
index d9e53c299..62a82098f 100644
--- a/dwds/test/readers/frontend_server_asset_reader_test.dart
+++ b/dwds/test/readers/frontend_server_asset_reader_test.dart
@@ -14,9 +14,7 @@ import '../fixtures/context.dart';
 import '../fixtures/utilities.dart';
 import '../utils/version_compatibility.dart';
 
-final packagesDir = absolutePath(
-  pathFromDwds: p.join('..', 'fixtures', '_test'),
-);
+final packagesDir = absolutePath(pathFromFixtures: '_test');
 
 final fixturesDir = absolutePath(pathFromDwds: p.join('test', 'fixtures'));
 
diff --git a/dwds/test/readers/proxy_server_asset_reader_test.dart b/dwds/test/readers/proxy_server_asset_reader_test.dart
index 86ed852d9..c9b76ccd0 100644
--- a/dwds/test/readers/proxy_server_asset_reader_test.dart
+++ b/dwds/test/readers/proxy_server_asset_reader_test.dart
@@ -12,7 +12,7 @@ import '../utils/version_compatibility.dart';
 
 void main() {
   group('ProxyServerAssetReader', () {
-    final context = TestContext(nullSafety: NullSafety.weak);
+    final context = TestContext.withWeakNullSafety();
     late ProxyServerAssetReader assetReader;
     setUpAll(() async {
       await context.setUp();
diff --git a/dwds/test/refresh_test.dart b/dwds/test/refresh_test.dart
index 141df6faa..2fc125b9e 100644
--- a/dwds/test/refresh_test.dart
+++ b/dwds/test/refresh_test.dart
@@ -18,7 +18,7 @@ import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
 
 import 'fixtures/context.dart';
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 ChromeProxyService get service =>
     fetchChromeProxyService(context.debugConnection);
 WipConnection get tabConnection => context.tabConnection;
diff --git a/dwds/test/reload_test.dart b/dwds/test/reload_test.dart
index 970e3797e..9c0815fa1 100644
--- a/dwds/test/reload_test.dart
+++ b/dwds/test/reload_test.dart
@@ -6,17 +6,17 @@
 @TestOn('vm')
 @Timeout(Duration(minutes: 5))
 import 'package:dwds/src/loaders/strategy.dart';
-import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:vm_service/vm_service.dart';
 
 import 'fixtures/context.dart';
 import 'fixtures/logging.dart';
+import 'fixtures/utilities.dart';
 
-final context = TestContext(
-  path: 'append_body/index.html',
-  entry: p.join(
-      '..', 'fixtures', '_testSound', 'example', 'append_body', 'main.dart'),
+final context = TestContext.withSoundNullSafety(
+  webAssetsPath: webCompatiblePath(['example', 'append_body']),
+  dartEntryFileName: 'main.dart',
+  htmlEntryFileName: 'index.html',
 );
 
 void main() {
diff --git a/dwds/test/restore_breakpoints_test.dart b/dwds/test/restore_breakpoints_test.dart
index d5079542d..e21c3e35a 100644
--- a/dwds/test/restore_breakpoints_test.dart
+++ b/dwds/test/restore_breakpoints_test.dart
@@ -15,7 +15,7 @@ import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
 import 'fixtures/context.dart';
 import 'fixtures/logging.dart';
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 ChromeProxyService get service =>
     fetchChromeProxyService(context.debugConnection);
 WipConnection get tabConnection => context.tabConnection;
diff --git a/dwds/test/run_request_test.dart b/dwds/test/run_request_test.dart
index 9856c6665..5b461bdf7 100644
--- a/dwds/test/run_request_test.dart
+++ b/dwds/test/run_request_test.dart
@@ -12,7 +12,7 @@ import 'package:vm_service/vm_service.dart';
 
 import 'fixtures/context.dart';
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 
 ChromeProxyService get service =>
     fetchChromeProxyService(context.debugConnection);
diff --git a/dwds/test/screenshot_test.dart b/dwds/test/screenshot_test.dart
index 34f98bb74..9410abf1e 100644
--- a/dwds/test/screenshot_test.dart
+++ b/dwds/test/screenshot_test.dart
@@ -8,7 +8,7 @@ import 'package:test/test.dart';
 
 import 'fixtures/context.dart';
 
-final context = TestContext();
+final context = TestContext.withSoundNullSafety();
 
 void main() {
   setUpAll(() async {
diff --git a/dwds/test/variable_scope_test.dart b/dwds/test/variable_scope_test.dart
index 8ec92bf4c..19a7c7eb6 100644
--- a/dwds/test/variable_scope_test.dart
+++ b/dwds/test/variable_scope_test.dart
@@ -7,24 +7,18 @@
 import 'package:dwds/src/connections/debug_connection.dart';
 import 'package:dwds/src/debugging/dart_scope.dart';
 import 'package:dwds/src/services/chrome_proxy_service.dart';
-import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:vm_service/vm_service.dart';
 import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
 
 import 'fixtures/context.dart';
+import 'fixtures/utilities.dart';
 
-final context = TestContext(
-    path: 'scopes/scopes.html',
-    entry: p.join(
-      '..',
-      'fixtures',
-      '_testSound',
-      'example',
-      'scopes',
-      'scopes_main.dart',
-    ));
-
+final context = TestContext.withSoundNullSafety(
+  webAssetsPath: webCompatiblePath(['example', 'scopes']),
+  dartEntryFileName: 'main.dart',
+  htmlEntryFileName: 'scopes.html',
+);
 ChromeProxyService get service =>
     fetchChromeProxyService(context.debugConnection);
 WipConnection get tabConnection => context.tabConnection;
@@ -124,7 +118,7 @@ void main() {
       await service.streamListen('Debug');
       stream = service.onEvent('Debug');
       mainScript = scripts.scripts!
-          .firstWhere((each) => each.uri!.contains('scopes_main.dart'));
+          .firstWhere((each) => each.uri!.contains('main.dart'));
     });
 
     tearDown(() async {
diff --git a/fixtures/_test/example/scopes/scopes_main.dart b/fixtures/_test/example/scopes/main.dart
similarity index 100%
rename from fixtures/_test/example/scopes/scopes_main.dart
rename to fixtures/_test/example/scopes/main.dart
diff --git a/fixtures/_test/example/scopes/scopes.html b/fixtures/_test/example/scopes/scopes.html
index 6c3307394..d93440a94 100644
--- a/fixtures/_test/example/scopes/scopes.html
+++ b/fixtures/_test/example/scopes/scopes.html
@@ -1,7 +1,7 @@
 <html>
 
 <head>
-  <script defer src="scopes_main.dart.js"></script>
+  <script defer src="main.dart.js"></script>
 </head>
 
 </html>
diff --git a/fixtures/_testSound/example/scopes/scopes_main.dart b/fixtures/_testSound/example/scopes/main.dart
similarity index 100%
rename from fixtures/_testSound/example/scopes/scopes_main.dart
rename to fixtures/_testSound/example/scopes/main.dart
diff --git a/fixtures/_testSound/example/scopes/scopes.html b/fixtures/_testSound/example/scopes/scopes.html
index 6c3307394..d93440a94 100644
--- a/fixtures/_testSound/example/scopes/scopes.html
+++ b/fixtures/_testSound/example/scopes/scopes.html
@@ -1,7 +1,7 @@
 <html>
 
 <head>
-  <script defer src="scopes_main.dart.js"></script>
+  <script defer src="main.dart.js"></script>
 </head>
 
 </html>