FlutterDriver.Connect Requires VM_SERVICE_URL or String?

Question

My app is the basic counter, with a FlutterDriver for UI Automation. My conundrum is when I attempt to run my test, it tells me that I need to specify a connection or set the VM_SERVICE_URL

ERROR:

DriverError: Could not determine URL to connect to application. Either the VM_SERVICE_URL environment variable should be set, or an explicit URL should be provided to the FlutterDriver.connect() method.

I've tried a few things.

• Using FlutterDriver.connect();
• Setting the VM_SERVICE_URL in Terminal (MacOS)
• Setting the Dart Command Line to include VM_SERVICE_URL with a value

The most success I've had is with the code below. By adding enableFlutterDriverExtension to the lib/main.dart, then executing lib/main.dart, I can copy/paste the ws://127.0.0.1 connection into the test/my_test.dart. This allows me to successfully run my tests, but this isn't an ideal process.

Is there a way to pull in the connection string automatically?

Why does Platform.environment['VM_SERVICE_URL'] always return null despite my having set it?

lib/main.dart

void main() {

  enableFlutterDriverExtension();
  runApp(const MyApp());
}

test/main_app.dart

void main() {
//  enableFlutterDriverExtension();
  MainApp.main();
  MyTest.main();

}

test/my_test.dart

void main() {

  FlutterDriver? driver;

  dynamic DartVmServiceUrl;
  DartVmServiceUrl ??= Platform.environment['VM_SERVICE_URL'];
  print('VM_SERVICE_URL:\t${DartVmServiceUrl}');
  String vmServURL = 'ws://127.0.0.1:59488/WK8KTNVXXOo=/ws';

  setUpAll( () async {
    driver = await FlutterDriver.connect(dartVmServiceUrl: vmServURL);
  });

  tearDownAll( () {
    driver?.close();
  });

  test('Push Button',() async {
    var pushMeButton = find.byValueKey('IncrementButton');
    await driver!.tap(pushMeButton);

  }  );


}

Answer 1

you have to move the files in the specific folders you see below, then try to run from terminal with

flutter drive \
--driver=test/my_test.dart \
--target=test_driver/test_driver.dart

in your lib/main.dart you don't need enableFlutterDriverExtension(); because it is already linked to your main() in the test_driver.dart

also your main in test_driver/test_driver.dart should look like this:

import 'package:{here}/main.dart' as app; // insert here your main app
import 'package:flutter_driver/driver_extension.dart';

void main() {
  enableFlutterDriverExtension();
  app.main();
}

your my_test.dart should look like this:

import 'package:flutter_driver/flutter_driver.dart';
import 'package:test/test.dart';

void main() {
  late FlutterDriver driver;

  setUpAll(() async {
    driver = await FlutterDriver.connect();
  });

  tearDownAll(() {
    driver.close();
  });

  test('check flutter driver health', () async {
    Health health = await driver.checkHealth();
    print(health.status);
  });
}

give attention to use the correct packages to avoid this error.

Error: Not found: 'dart:ui' import 'dart:ui';