public/dart/fuchsia_modular_test/lib/src/test_harness_fixtures.dart

// Copyright 2019 The Fuchsia 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 'dart:async';
import 'dart:math';

import 'package:fidl_fuchsia_modular_testing/fidl_async.dart' as fidl_testing;
import 'package:fidl_fuchsia_sys/fidl_async.dart' as fidl_sys;
import 'package:fuchsia_services/services.dart';

const _modularTestHarnessURL =
    'fuchsia-pkg://fuchsia.com/modular_test_harness#meta/modular_test_harness.cmx';

/// Launches the test harness and connects to it.
///
/// It is the responsibility of the caller to close the connection to the
/// harness after each test.
Future<fidl_testing.TestHarnessProxy> launchTestHarness() async {
  final harness = fidl_testing.TestHarnessProxy();
  final launcher = fidl_sys.LauncherProxy();
  final incoming = Incoming();

  final componentControllerProxy = fidl_sys.ComponentControllerProxy();

  StartupContext.fromStartupInfo().incoming.connectToService(launcher);
  final launchInfo = fidl_sys.LaunchInfo(
      url: _modularTestHarnessURL,
      directoryRequest: incoming.request().passChannel());
  await launcher.createComponent(
      launchInfo, componentControllerProxy.ctrl.request());

  launcher.ctrl.close();

  // hold a reference to the componentControllerProxy so it lives as long as the
  // harness and does not kill the service if it is garbage collected.
  // ignore: unawaited_futures
  harness.ctrl.whenClosed.then((_) => componentControllerProxy.ctrl.close());

  incoming.connectToService(harness);

  return harness;
}

/// Generates a random component url with the correct format
String generateComponentUrl() {
  final rand = Random();
  final name = List.generate(10, (_) => rand.nextInt(9).toString()).join('');
  return 'fuchsia-pkg://example.com/$name#meta/$name.cmx';
}