Shard DWDS tests and fix CI test flakiness

dwds/mono_pkg.yaml

@@ -11,17 +11,52 @@ stages:
       - test: test/build/min_sdk_test.dart --run-skipped
       sdk: stable
   - unit_test:
+    # Linux extension tests:
+    # Note: `Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &` must be
+    # run first for Linux.
     - group:
       - command: Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &
-      - test:
+      - test: --tags=extension
       sdk:
         - dev
         - stable
-    - test:
-      os: windows
+      os:
+        - linux
+     # Windows extension tests:
+    - group:
+      - test: --tags=extension
+      sdk:
+        - dev
+        - stable
+      os:
+        - windows
+    # First test shard:
+    - group:
+      - test: --total-shards 3 --shard-index 0 --exclude-tags=extension
+      sdk:
+        - dev
+        - stable
+      os: 
+        - linux
+        - windows
+    # Second test shard:
+    - group:
+      - test: --total-shards 3 --shard-index 1 --exclude-tags=extension
+      sdk:
+        - dev
+        - stable
+      os: 
+        - linux
+        - windows
+    # Third test shard:
+    - group:
+      - test: --total-shards 3 --shard-index 2 --exclude-tags=extension
       sdk:
         - dev
         - stable
+      os: 
+        - linux
+        - windows
   - beta_cron:
     - analyze: .
       sdk: beta

dwds/test/dart_uri_file_uri_test.dart

@@ -3,13 +3,13 @@
 // BSD-style license that can be found in the LICENSE file.
 
 @TestOn('vm')
-import 'dart:io';
 
 import 'package:dwds/src/utilities/dart_uri.dart';
 import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 
 import 'fixtures/context.dart';
+import 'fixtures/utilities.dart';
 import 'utils/version_compatibility.dart';
 
 final context = TestContext(
@@ -20,17 +20,13 @@ final context = TestContext(
   nullSafety: NullSafety.weak,
 );
 
-final dwdsDir = Directory.current.absolute.path;
-
 /// The directory for the general _test package.
-final testDir = p.normalize(p.absolute(p.relative(
-  p.join('..', 'fixtures', '_test'),
-  from: p.current,
-)));
+final testDir = absolutePath(pathFromDwds: p.join('..', 'fixtures', '_test'));
 
 /// The directory for the _testPackage package (contained within dwds), which
 /// imports _test.
-final testPackageDir = context.workingDirectory;
+final testPackageDir =
+    absolutePath(pathFromDwds: p.join('..', 'fixtures', '_testPackage'));
 
 // This tests converting file Uris into our internal paths.
 //

dwds/test/fixtures/context.dart

@@ -114,8 +114,6 @@ class TestContext {
 
   NullSafety nullSafety;
 
-  late String dwdsDirectory;
-
   TestContext({
     String? directory,
     String? entry,
@@ -124,18 +122,15 @@ class TestContext {
     this.pathToServe = 'example',
   }) {
     final pathParts = p.split(p.current);
-    assert(pathParts.contains('dwds'));
-    dwdsDirectory = p.joinAll(
-      pathParts.sublist(0, pathParts.indexOf('dwds') + 1),
-    );
+    assert(pathParts.contains('webdev'));
     final defaultPackage =
         nullSafety == NullSafety.sound ? '_testSound' : '_test';
     final defaultDirectory = p.join('..', 'fixtures', defaultPackage);
     final defaultEntry = p.join('..', 'fixtures', defaultPackage, 'example',
         'append_body', 'main.dart');
 
-    workingDirectory = p.normalize(p.absolute(
-        p.relative(directory ?? defaultDirectory, from: dwdsDirectory)));
+    workingDirectory =
+        absolutePath(pathFromDwds: directory ?? defaultDirectory);
 
     DartUri.currentDirectory = workingDirectory;
 
@@ -144,8 +139,7 @@ class TestContext {
     _packageConfigFile =
         p.toUri(p.join(workingDirectory, '.dart_tool/package_config.json'));
 
-    final entryFilePath = p.normalize(
-        p.absolute(p.relative(entry ?? defaultEntry, from: dwdsDirectory)));
+    final entryFilePath = absolutePath(pathFromDwds: entry ?? defaultEntry);
 
     _logger.info('Serving: $pathToServe/$path');
     _logger.info('Project: $_projectDirectory');
@@ -430,12 +424,6 @@ class TestContext {
     }
   }
 
-  String absoluteDwdsPath(String relativePath) =>
-      p.normalize(p.absolute(p.relative(
-        relativePath,
-        from: dwdsDirectory,
-      )));
-
   Future<void> startDebugging() async {
     debugConnection = await testServer.dwds.debugConnection(appConnection);
     _webkitDebugger = WebkitDebugger(WipDebugger(tabConnection));
@@ -482,16 +470,8 @@ class TestContext {
   }
 
   Future<void> _buildDebugExtension() async {
-    final currentDir = Directory.current.path;
-    if (!currentDir.endsWith('dwds')) {
-      throw StateError(
-          'Expected to be in /dwds directory, instead path was $currentDir.');
-    }
-    final process = await Process.run(
-      'tool/build_extension.sh',
-      ['prod'],
-      workingDirectory: '$currentDir/debug_extension',
-    );
+    final process = await Process.run('tool/build_extension.sh', ['prod'],
+        workingDirectory: absolutePath(pathFromDwds: 'debug_extension'));
     print(process.stdout);
   }
 

dwds/test/fixtures/utilities.dart

@@ -9,6 +9,29 @@ import 'package:build_daemon/constants.dart';
 import 'package:build_daemon/data/server_log.dart';
 import 'package:path/path.dart' as p;
 
+const webdevDirName = 'webdev';
+const dwdsDirName = 'dwds';
+
+/// The path to the DWDS directory in the local machine, e.g.
+/// "/workstation/webdev/dwds".
+String get dwdsPath {
+  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,
+    ],
+  );
+}
+
+/// 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),
+    );
+
 /// Connects to the `build_runner` daemon.
 Future<BuildDaemonClient> connectClient(String workingDirectory,
         List<String> options, Function(ServerLog) logHandler) =>

dwds/test/package_uri_mapper_test.dart

@@ -11,9 +11,7 @@ import 'package:file/local.dart';
 import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 
-import 'fixtures/context.dart';
-
-final testContext = TestContext();
+import 'fixtures/utilities.dart';
 
 void main() {
   for (final useDebuggerModuleNames in [true, false]) {
@@ -32,7 +30,8 @@ void main() {
       final resolvedPath =
           '/webdev/fixtures/_testPackageSound/lib/test_library.dart';
 
-      final testPackageSoundPath = testContext.absoluteDwdsPath(p.join(
+      final testPackageSoundPath = absolutePath(
+          pathFromDwds: p.join(
         '..',
         'fixtures',
         '_testPackageSound',

dwds/test/readers/frontend_server_asset_reader_test.dart

@@ -13,7 +13,11 @@ import '../fixtures/context.dart';
 import '../fixtures/utilities.dart';
 import '../utils/version_compatibility.dart';
 
-final packagesDir = p.relative('../fixtures/_test', from: p.current);
+final packagesDir = absolutePath(
+  pathFromDwds: p.join('..', 'fixtures', '_test'),
+);
+
+final fixturesDir = absolutePath(pathFromDwds: p.join('test', 'fixtures'));
 
 void main() {
   late FrontendServerAssetReader assetReader;
@@ -22,12 +26,11 @@ void main() {
   late File mapOriginal;
 
   Future<void> createTempFixtures() async {
-    final fixtures = p.join('test', 'fixtures');
     tempFixtures = await Directory.systemTemp.createTemp('dwds_test_fixtures');
     await tempFixtures.create();
-    jsonOriginal = await File(p.join(fixtures, 'main.dart.dill.json'))
+    jsonOriginal = await File(p.join(fixturesDir, 'main.dart.dill.json'))
         .copy(p.join(tempFixtures.path, 'main.dart.dill.json'));
-    mapOriginal = await File(p.join(fixtures, 'main.dart.dill.map'))
+    mapOriginal = await File(p.join(fixturesDir, 'main.dart.dill.map'))
         .copy(p.join(tempFixtures.path, 'main.dart.dill.map'));
   }