错误状态:在“when()”中未调用模拟方法.是一个真正的方法叫

Question

我正在尝试使用 mockito 模拟颤振中的httpRequest。

在这里，我定义一个全局 http 客户端：

library utgard.globals;
import 'package:http/http.dart' as http;
http.Client httpClient = http.Client();

然后我在集成测试中替换：

import 'package:flutter_driver/driver_extension.dart';
import 'package:http/http.dart' as http;
import 'package:utgard/globals.dart' as globals;
import 'package:mockito/mockito.dart';
import 'package:utgard/main.dart' as app;
class MockClient extends Mock implements http.Client {}
void main() {
  final MockClient client = MockClient();
  globals.httpClient = client;
  enableFlutterDriverExtension();
  app.main();
}

然后我尝试使用when mockito：

test('login with correct password', () async {
      final client = MockClient();
      when(globals.httpClient.post('http://www.google.com'))
          .thenAnswer((_) async => http.Response('{"title": "Test"}', 200));
      await driver.enterText('000000');
      await driver.tap(loginContinuePasswordButton);
    });

但是我收到以下错误：

错误状态：when()内未调用模拟方法。是真正的方法吗？

Answer 1

当您实现要模拟的方法而不是让 Mockito 执行此操作时，可能会发生此问题。

下面的代码将返回Bad state: Mock method was not called within when(). Was a real method called?：

class MockFirebaseAuth extends Mock implements FirebaseAuth {
  FirebaseUser _currentUser;
  MockFirebaseAuth(this._currentUser);
  // This method causes the issue.
  Future<FirebaseUser> currentUser() async {
    return _currentUser;
  }
}
final user = MockFirebaseUser();
final mockFirebaseAuth = MockFirebaseAuth(user);
// Will throw `Bad state: Mock method was not called within `when()`. Was a real method called?`
when(mockFirebaseAuth.currentUser())
    .thenAnswer((_) => Future.value(user));

你想要的是：

class MockFirebaseAuth extends Mock implements FirebaseAuth {}
final user = MockFirebaseUser();
final mockFirebaseAuth = MockFirebaseAuth();
// Will work as expected
when(mockFirebaseAuth.currentUser())
    .thenAnswer((_) => Future.value(user));

当您尝试在非模拟子语言上调用when()时，也会发生此问题：

class MyClass {
  String doSomething() {
    return 'test';
  }
}
final myClassInstance = MyClass();
// Will throw `Bad state: Mock method was not called within `when()`. Was a real method called?`
when(myClassInstance.doSomething())
    .thenReturn((_) => 'mockedValue');

Answer 2

还有一种可能性。如果这种情况发生在您的模拟对象上，那么它可能已经过时了。在这种情况下，请尝试使用

flutter pub run build_runner build --delete-conflicting-outputs

Answer 3

请在拆卸或安装结束时声明resetMocktailState()，因此测试用例不会影响以后的测试用例。

Answer 4

我找到的解决方案是在 test_driver/app.dart 中定义模拟，然后调用 runApp 函数，这样即使进行颤振集成测试，您也可以应用模拟：

import 'package:flutter/widgets.dart';
import 'package:flutter_driver/driver_extension.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:utgard/business/config/globals.dart';
import 'package:utgard/main.dart' as app;
class MockClient extends Mock implements http.Client {}
void main() {
  enableFlutterDriverExtension();
  final MockClient client = MockClient();
  // make your mocks here
  httpClient = client;
  runApp(app.MyApp());
}

由于它可以成为一个巨大的代码来模拟那里的所有请求，因此您可以创建一个单独的函数以更好地组织代码：

import 'package:flutter/widgets.dart';
import 'package:flutter_driver/driver_extension.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:utgard/business/config/globals.dart';
import 'package:utgard/main.dart' as app;
class MockClient extends Mock implements http.Client {}
void main() {
  enableFlutterDriverExtension();
  final MockClient client = MockClient();
  makeMock();
  httpClient = client;
  runApp(app.MyApp());
}