Support tags when running tests from command line (#55152)

dev/automated_tests/flutter_test/filtering_tag_test.dart

@@ -0,0 +1,14 @@
+// Copyright 2014 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:test/test.dart' hide TypeMatcher, isInstanceOf;
+
+void main() {
+  test('included', () {
+    expect(2 + 2, 4);
+  }, tags: <String>['include-tag']);
+  test('excluded', () {
+    throw 'this test should have been filtered out';
+  }, tags: <String>['exclude-tag']);
+}

packages/flutter_tools/lib/src/commands/test.dart

@@ -42,6 +42,14 @@ class TestCommand extends FlutterCommand {
         valueHelp: 'substring',
         splitCommas: false,
       )
+      ..addOption('tags',
+        abbr: 't',
+        help: 'Run only tests associated with tags',
+      )
+      ..addOption('exclude-tags',
+        abbr: 'x',
+        help: 'Run only tests WITHOUT given tags',
+      )
       ..addFlag('start-paused',
         defaultsTo: false,
         negatable: false,
@@ -160,6 +168,8 @@ class TestCommand extends FlutterCommand {
     final bool buildTestAssets = boolArg('test-assets');
     final List<String> names = stringsArg('name');
     final List<String> plainNames = stringsArg('plain-name');
+    final String tags = stringArg('tags');
+    final String excludeTags = stringArg('exclude-tags');
     final FlutterProject flutterProject = FlutterProject.current();
 
     if (buildTestAssets && flutterProject.manifest.assets.isNotEmpty) {
@@ -250,6 +260,8 @@ class TestCommand extends FlutterCommand {
       workDir: workDir,
       names: names,
       plainNames: plainNames,
+      tags: tags,
+      excludeTags: excludeTags,
       watcher: watcher,
       enableObservatory: collector != null || startPaused || boolArg('enable-vmservice'),
       startPaused: startPaused,

packages/flutter_tools/lib/src/test/runner.dart

@@ -31,6 +31,8 @@ abstract class FlutterTestRunner {
     Directory workDir,
     List<String> names = const <String>[],
     List<String> plainNames = const <String>[],
+    String tags,
+    String excludeTags,
     bool enableObservatory = false,
     bool startPaused = false,
     bool disableServiceAuthCodes = false,
@@ -62,6 +64,8 @@ class _FlutterTestRunnerImpl implements FlutterTestRunner {
     Directory workDir,
     List<String> names = const <String>[],
     List<String> plainNames = const <String>[],
+    String tags,
+    String excludeTags,
     bool enableObservatory = false,
     bool startPaused = false,
     bool disableServiceAuthCodes = false,
@@ -104,6 +108,10 @@ class _FlutterTestRunnerImpl implements FlutterTestRunner {
         ...<String>['--plain-name', plainName],
       if (randomSeed != null)
         '--test-randomize-ordering-seed=$randomSeed',
+      if (tags != null)
+        ...<String>['--tags', tags],
+      if (excludeTags != null)
+        ...<String>['--exclude-tags', excludeTags],
     ];
     if (web) {
       final String tempBuildDir = globals.fs.systemTempDirectory

packages/flutter_tools/test/commands.shard/hermetic/test_test.dart

@@ -164,6 +164,8 @@ class FakeFlutterTestRunner implements FlutterTestRunner {
     Directory workDir,
     List<String> names = const <String>[],
     List<String> plainNames = const <String>[],
+    String tags,
+    String excludeTags,
     bool enableObservatory = false,
     bool startPaused = false,
     bool disableServiceAuthCodes = false,

packages/flutter_tools/test/commands.shard/permeable/test_test.dart

@@ -96,6 +96,35 @@ void main() {
     expect(result.exitCode, 0);
   });
 
+  testUsingContext('flutter test should run a test with a given tag', () async {
+    Cache.flutterRoot = '../..';
+    final ProcessResult result = await _runFlutterTest('filtering_tag', automatedTestsDirectory, flutterTestDirectory,
+        extraArguments: const <String>['--tags', 'include-tag']);
+    if (!(result.stdout as String).contains('+1: All tests passed')) {
+      fail('unexpected output from test:\n\n${result.stdout}\n-- end stdout --\n\n');
+    }
+    expect(result.exitCode, 0);
+  });
+
+  testUsingContext('flutter test should not run a test with excluded tag', () async {
+    Cache.flutterRoot = '../..';
+    final ProcessResult result = await _runFlutterTest('filtering_tag', automatedTestsDirectory, flutterTestDirectory,
+        extraArguments: const <String>['--exclude-tags', 'exclude-tag']);
+    if (!(result.stdout as String).contains('+1: All tests passed')) {
+      fail('unexpected output from test:\n\n${result.stdout}\n-- end stdout --\n\n');
+    }
+    expect(result.exitCode, 0);
+  });
+
+  testUsingContext('flutter test should run all tests when tags are unspecified', () async {
+    Cache.flutterRoot = '../..';
+    final ProcessResult result = await _runFlutterTest('filtering_tag', automatedTestsDirectory, flutterTestDirectory);
+    if (!(result.stdout as String).contains('+1 -1: Some tests failed')) {
+      fail('unexpected output from test:\n\n${result.stdout}\n-- end stdout --\n\n');
+    }
+    expect(result.exitCode, 1);
+  });
+
   testUsingContext('flutter test should test runs to completion', () async {
     Cache.flutterRoot = '../..';
     final ProcessResult result = await _runFlutterTest('trivial', automatedTestsDirectory, flutterTestDirectory,