[flutter_plugin_tool] Add support for running Windows unit tests

script/tool/CHANGELOG.md

@@ -5,6 +5,7 @@
 - Pubspec validation now checks for `implements` in implementation packages.
 - Pubspec valitation now checks the full relative path of `repository` entries.
 - `build-examples` now supports UWP plugins via a `--winuwp` flag.
+- `native-test` now supports `--windows` for unit tests.
 - **Breaking change**: `publish` no longer accepts `--no-tag-release` or
   `--no-push-flags`. Releases now always tag and push.
 - **Breaking change**: `publish`'s `--package` flag has been replaced with the

script/tool/lib/src/common/file_utils.dart

@@ -0,0 +1,20 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:file/file.dart';
+
+/// Returns a [File] created by appending all but the last item in [components]
+/// to [base] as subdirectories, then appending the last as a file.
+///
+/// Example:
+///   childFileWithSubcomponents(rootDir, ['foo', 'bar', 'baz.txt'])
+/// creates a File representing /rootDir/foo/bar/baz.txt.
+File childFileWithSubcomponents(Directory base, List<String> components) {
+  Directory dir = base;
+  final String basename = components.removeLast();
+  for (final String directoryName in components) {
+    dir = dir.childDirectory(directoryName);
+  }
+  return dir.childFile(basename);
+}

script/tool/lib/src/common/plugin_utils.dart

@@ -17,7 +17,7 @@ enum PlatformSupport {
   federated,
 }
 
-/// Returns whether the given [package] is a Flutter [platform] plugin.
+/// Returns true if [package] is a Flutter [platform] plugin.
 ///
 /// It checks this by looking for the following pattern in the pubspec:
 ///
@@ -30,7 +30,7 @@ enum PlatformSupport {
 /// implementation in order to return true.
 bool pluginSupportsPlatform(
   String platform,
-  RepositoryPackage package, {
+  RepositoryPackage plugin, {
   PlatformSupport? requiredMode,
   String? variant,
 }) {
@@ -41,32 +41,12 @@ bool pluginSupportsPlatform(
       platform == kPlatformWindows ||
       platform == kPlatformLinux);
   try {
-    final YamlMap pubspecYaml =
-        loadYaml(package.pubspecFile.readAsStringSync()) as YamlMap;
-    final YamlMap? flutterSection = pubspecYaml['flutter'] as YamlMap?;
-    if (flutterSection == null) {
-      return false;
-    }
-    final YamlMap? pluginSection = flutterSection['plugin'] as YamlMap?;
-    if (pluginSection == null) {
-      return false;
-    }
-    final YamlMap? platforms = pluginSection['platforms'] as YamlMap?;
-    if (platforms == null) {
-      // Legacy plugin specs are assumed to support iOS and Android. They are
-      // never federated.
-      if (requiredMode == PlatformSupport.federated) {
-        return false;
-      }
-      if (!pluginSection.containsKey('platforms')) {
-        return platform == kPlatformIos || platform == kPlatformAndroid;
-      }
-      return false;
-    }
-    final YamlMap? platformEntry = platforms[platform] as YamlMap?;
+    final YamlMap? platformEntry =
+        _readPlatformPubspecSectionForPlugin(platform, plugin);
     if (platformEntry == null) {
       return false;
     }
+
     // If the platform entry is present, then it supports the platform. Check
     // for required mode if specified.
     if (requiredMode != null) {
@@ -97,9 +77,67 @@ bool pluginSupportsPlatform(
     }
 
     return true;
+  } on YamlException {
+    return false;
+  }
+}
+
+/// Returns true if [plugin] includes native code for [platform], as opposed to
+/// being implemented entirely in Dart.
+bool pluginHasNativeCodeForPlatform(String platform, RepositoryPackage plugin) {
+  if (platform == kPlatformWeb) {
+    // Web plugins are always Dart-only.
+    return false;
+  }
+  try {
+    final YamlMap? platformEntry =
+        _readPlatformPubspecSectionForPlugin(platform, plugin);
+    if (platformEntry == null) {
+      return false;
+    }
+    // All other platforms currently use pluginClass for indicating the native
+    // code in the plugin.
+    final String? pluginClass = platformEntry['pluginClass'] as String?;
+    // TODO(stuartmorgan): Remove the check for 'none' once none of the plugins
+    // in the repository use that workaround. See
+    // https://github.com/flutter/flutter/issues/57497 for context.
+    return pluginClass != null && pluginClass != 'none';
   } on FileSystemException {
     return false;
   } on YamlException {
     return false;
   }
 }
+
+/// Returns the
+///   flutter:
+///     plugin:
+///       platforms:
+///         [platform]:
+/// section from [plugin]'s pubspec.yaml, or null if either it is not present,
+/// or the pubspec couldn't be read.
+YamlMap? _readPlatformPubspecSectionForPlugin(
+    String platform, RepositoryPackage plugin) {
+  try {
+    final File pubspecFile = plugin.pubspecFile;
+    final YamlMap pubspecYaml =
+        loadYaml(pubspecFile.readAsStringSync()) as YamlMap;
+    final YamlMap? flutterSection = pubspecYaml['flutter'] as YamlMap?;
+    if (flutterSection == null) {
+      return null;
+    }
+    final YamlMap? pluginSection = flutterSection['plugin'] as YamlMap?;
+    if (pluginSection == null) {
+      return null;
+    }
+    final YamlMap? platforms = pluginSection['platforms'] as YamlMap?;
+    if (platforms == null) {
+      return null;
+    }
+    return platforms[platform] as YamlMap?;
+  } on FileSystemException {
+    return null;
+  } on YamlException {
+    return null;
+  }
+}

script/tool/lib/src/native_test_command.dart

@@ -40,6 +40,7 @@ class NativeTestCommand extends PackageLoopingCommand {
     argParser.addFlag(kPlatformAndroid, help: 'Runs Android tests');
     argParser.addFlag(kPlatformIos, help: 'Runs iOS tests');
     argParser.addFlag(kPlatformMacos, help: 'Runs macOS tests');
+    argParser.addFlag(kPlatformWindows, help: 'Runs Windows tests');
 
     // By default, both unit tests and integration tests are run, but provide
     // flags to disable one or the other.
@@ -80,6 +81,7 @@ this command.
       kPlatformAndroid: _PlatformDetails('Android', _testAndroid),
       kPlatformIos: _PlatformDetails('iOS', _testIos),
       kPlatformMacos: _PlatformDetails('macOS', _testMacOS),
+      kPlatformWindows: _PlatformDetails('Windows', _testWindows),
     };
     _requestedPlatforms = _platforms.keys
         .where((String platform) => getBoolArg(platform))
@@ -96,6 +98,11 @@ this command.
       throw ToolExit(exitInvalidArguments);
     }
 
+    if (getBoolArg(kPlatformWindows) && getBoolArg(_integrationTestFlag)) {
+      logWarning('This command currently only supports unit tests for Windows. '
+          'See https://github.com/flutter/flutter/issues/70233.');
+    }
+
     // iOS-specific run-level state.
     if (_requestedPlatforms.contains('ios')) {
       String destination = getStringArg(_iosDestinationFlag);
@@ -119,16 +126,20 @@ this command.
   Future<PackageResult> runForPackage(RepositoryPackage package) async {
     final List<String> testPlatforms = <String>[];
     for (final String platform in _requestedPlatforms) {
-      if (pluginSupportsPlatform(platform, package,
+      if (!pluginSupportsPlatform(platform, package,
           requiredMode: PlatformSupport.inline)) {
-        testPlatforms.add(platform);
-      } else {
         print('No implementation for ${_platforms[platform]!.label}.');
+        continue;
       }
+      if (!pluginHasNativeCodeForPlatform(platform, package)) {
+        print('No native code for ${_platforms[platform]!.label}.');
+        continue;
+      }
+      testPlatforms.add(platform);
     }
 
     if (testPlatforms.isEmpty) {
-      return PackageResult.skip('Not implemented for target platform(s).');
+      return PackageResult.skip('Nothing to test for target platform(s).');
     }
 
     final _TestMode mode = _TestMode(
@@ -228,6 +239,8 @@ this command.
       final bool hasIntegrationTests =
           exampleHasNativeIntegrationTests(example);
 
+      // TODO(stuartmorgan): Make !hasUnitTests fatal. See
+      // https://github.com/flutter/flutter/issues/85469
       if (mode.unit && !hasUnitTests) {
         _printNoExampleTestsMessage(example, 'Android unit');
       }
@@ -335,6 +348,9 @@ this command.
     for (final RepositoryPackage example in plugin.getExamples()) {
       final String exampleName = example.displayName;
 
+      // TODO(stuartmorgan): Always check for RunnerTests, and make it fatal if
+      // no examples have it. See
+      // https://github.com/flutter/flutter/issues/85469
       if (testTarget != null) {
         final Directory project = example.directory
             .childDirectory(platform.toLowerCase())
@@ -387,6 +403,71 @@ this command.
     return _PlatformResult(overallResult);
   }
 
+  Future<_PlatformResult> _testWindows(
+      RepositoryPackage plugin, _TestMode mode) async {
+    if (mode.integrationOnly) {
+      return _PlatformResult(RunState.skipped);
+    }
+
+    bool isTestBinary(File file) {
+      return file.basename.endsWith('_test.exe') ||
+          file.basename.endsWith('_tests.exe');
+    }
+
+    return _runGoogleTestTests(plugin,
+        buildDirectoryName: 'windows', isTestBinary: isTestBinary);
+  }
+
+  /// Finds every file in the [buildDirectoryName] subdirectory of [plugin]'s
+  /// build directory for which [isTestBinary] is true, and runs all of them,
+  /// returning the overall result.
+  ///
+  /// The binaries are assumed to be Google Test test binaries, thus returning
+  /// zero for success and non-zero for failure.
+  Future<_PlatformResult> _runGoogleTestTests(
+    RepositoryPackage plugin, {
+    required String buildDirectoryName,
+    required bool Function(File) isTestBinary,
+  }) async {
+    final List<File> testBinaries = <File>[];
+    for (final RepositoryPackage example in plugin.getExamples()) {
+      final Directory buildDir = example.directory
+          .childDirectory('build')
+          .childDirectory(buildDirectoryName);
+      if (!buildDir.existsSync()) {
+        continue;
+      }
+      testBinaries.addAll(buildDir
+          .listSync(recursive: true)
+          .whereType<File>()
+          .where(isTestBinary)
+          .where((File file) {
+        // Only run the debug build of the unit tests, to avoid running the
+        // same tests multiple times.
+        final List<String> components = path.split(file.path);
+        return components.contains('debug') || components.contains('Debug');
+      }));
+    }
+
+    if (testBinaries.isEmpty) {
+      final String binaryExtension = platform.isWindows ? '.exe' : '';
+      printError(
+          'No test binaries found. At least one *_test(s)$binaryExtension '
+          'binary should be built by the example(s)');
+      return _PlatformResult(RunState.failed,
+          error: 'No $buildDirectoryName unit tests found');
+    }
+
+    bool passing = true;
+    for (final File test in testBinaries) {
+      print('Running ${test.basename}...');
+      final int exitCode =
+          await processRunner.runAndStream(test.path, <String>[]);
+      passing &= exitCode == 0;
+    }
+    return _PlatformResult(passing ? RunState.succeeded : RunState.failed);
+  }
+
   /// Prints a standard format message indicating that [platform] tests for
   /// [plugin]'s [example] are about to be run.
   void _printRunningExampleTestsMessage(

script/tool/lib/src/publish_plugin_command.dart

@@ -18,6 +18,7 @@ import 'package:pubspec_parse/pubspec_parse.dart';
 import 'package:yaml/yaml.dart';
 
 import 'common/core.dart';
+import 'common/file_utils.dart';
 import 'common/git_version_finder.dart';
 import 'common/plugin_command.dart';
 import 'common/process_runner.dart';
@@ -154,13 +155,10 @@ class PublishPluginCommand extends PluginCommand {
           await gitVersionFinder.getChangedPubSpecs();
 
       for (final String pubspecPath in changedPubspecs) {
-        // Convert git's Posix-style paths to a path that matches the current
-        // filesystem.
-        final String localStylePubspecPath =
-            path.joinAll(p.posix.split(pubspecPath));
-        final File pubspecFile = packagesDir.fileSystem
-            .directory((await gitDir).path)
-            .childFile(localStylePubspecPath);
+        // git outputs a relativa, Posix-style path.
+        final File pubspecFile = childFileWithSubcomponents(
+            packagesDir.fileSystem.directory((await gitDir).path),
+            p.posix.split(pubspecPath));
         yield PackageEnumerationEntry(RepositoryPackage(pubspecFile.parent),
             excluded: false);
       }

script/tool/test/common/file_utils_test.dart

@@ -0,0 +1,32 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:file/file.dart';
+import 'package:file/memory.dart';
+import 'package:flutter_plugin_tools/src/common/file_utils.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('works on Posix', () async {
+    final FileSystem fileSystem =
+        MemoryFileSystem(style: FileSystemStyle.posix);
+
+    final Directory base = fileSystem.directory('/').childDirectory('base');
+    final File file =
+        childFileWithSubcomponents(base, <String>['foo', 'bar', 'baz.txt']);
+
+    expect(file.absolute.path, '/base/foo/bar/baz.txt');
+  });
+
+  test('works on Windows', () async {
+    final FileSystem fileSystem =
+        MemoryFileSystem(style: FileSystemStyle.windows);
+
+    final Directory base = fileSystem.directory(r'C:\').childDirectory('base');
+    final File file =
+        childFileWithSubcomponents(base, <String>['foo', 'bar', 'baz.txt']);
+
+    expect(file.absolute.path, r'C:\base\foo\bar\baz.txt');
+  });
+}