[flutter_tools] do not make drive require pub if --no-pub is requested (#79379)

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

@@ -147,9 +147,15 @@ class DriveCommand extends RunCommandBase {
   }
 
   // `pub` must always be run due to the test script running from source,
-  // even if an application binary is used.
+  // even if an application binary is used. Default to true unless the user explicitly
+  // specified not to.
   @override
-  bool get shouldRunPub => true;
+  bool get shouldRunPub {
+    if (argResults.wasParsed('pub') && !boolArg('pub')) {
+      return false;
+    }
+    return true;
+  }
 
   FlutterDriverFactory _flutterDriverFactory;
   final FileSystem _fileSystem;

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

@@ -8,11 +8,15 @@ import 'package:file/memory.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/platform.dart';
+import 'package:flutter_tools/src/cache.dart';
 import 'package:flutter_tools/src/commands/drive.dart';
+import 'package:flutter_tools/src/dart/pub.dart';
 import 'package:flutter_tools/src/device.dart';
 import 'package:test/fake.dart';
 
 import '../../src/common.dart';
+import '../../src/context.dart';
+import '../../src/fakes.dart';
 
 void main() {
   FileSystem fileSystem;
@@ -25,6 +29,15 @@ void main() {
     platform = FakePlatform(operatingSystem: 'linux');
   });
 
+  setUpAll(() {
+    Cache.disableLocking();
+  });
+
+  tearDownAll(() {
+    Cache.enableLocking();
+  });
+
+
   testWithoutContext('drive --screenshot writes to expected output', () async {
     final Device screenshotDevice = ScreenshotDevice();
 
@@ -60,6 +73,33 @@ void main() {
     expect(logger.statusText, isEmpty);
     expect(logger.errorText, contains('Error taking screenshot: FileSystemException: Not a directory'));
   });
+
+  testUsingContext('shouldRunPub is true unless user specifies --no-pub', () async {
+    final DriveCommand command = DriveCommand(fileSystem: fileSystem, logger: logger, platform: platform);
+    fileSystem.file('lib/main.dart').createSync(recursive: true);
+    fileSystem.file('test_driver/main_test.dart').createSync(recursive: true);
+    fileSystem.file('pubspec.yaml').createSync();
+
+    try {
+      await createTestCommandRunner(command).run(const <String>['drive', '--no-pub']);
+    } on Exception {
+      // Expected to throw
+    }
+
+    expect(command.shouldRunPub, false);
+
+    try {
+      await createTestCommandRunner(command).run(const <String>['drive']);
+    } on Exception {
+      // Expected to throw
+    }
+
+    expect(command.shouldRunPub, true);
+  }, overrides: <Type, Generator>{
+    FileSystem: () => fileSystem,
+    ProcessManager: () => FakeProcessManager.any(),
+    Pub: () => FakePub(),
+  });
 }
 
 class ScreenshotDevice extends Fake implements Device {