收到此错误“类型‘Null’不是类型‘Future’的子类型

Question

void main() {
  late ApiManager apiManager;
  late MockHTTPClient mockHTTPClient;

  setUp(() {
    mockHTTPClient = MockHTTPClient();
    apiManager = ApiManager(mockHTTPClient);
  });
 test(
        'given UserRepository class when getUser function is called and status code is 200 then a usermodel should be returned',
        () async {
          // Arrange
          const mockResponse = '{"status": "200"}';
          String url = "url";
          when(() {
            return mockHTTPClient.post(Uri.parse(url));
          }).thenAnswer((invocation) => Future.delayed(Durations.short2,() => Response(mockResponse, 200),), );
          // Act
          final user = await apiManager.userLoginApi();
          // Assert
          expect(isuserExist, isA<Data()>());
        },
      );


Future<Data> userLoginApi({String? email, String? password}) async {
    final response = await client.post(
      Uri.parse('url'),
    );
    if (response.statusCode == 200) {
      Map<String, String> body = {
        "email": email.toString(),
        "password": password.toString()
      };
      return Data.fromJson(body);
    }
    throw Exception('Some Error Occurred');
  }

收到此错误“类型‘Null’不是类型‘Future’的子类型..另外，我应该在正文中传递什么。这是一个用户登录 api，其中包括电子邮件和通行证。由于它是一个测试用例，我无法通过用户凭据。

Answer 1

尝试改变这些：

  when(() => mockHTTPClient.post(Uri.parse(url)))
      .thenAnswer((_) async => Response(mockResponse, 200));

  // Act
  final user = await apiManager.userLoginApi(email: '[email protected]', password: 'test');
 //pass mock email and password here to the userLoginApi method.

还有：

Future<Data> userLoginApi({String? email, String? password}) async {
  final response = await client.post(
    Uri.parse('url'),
    body: {
      "email": email,
      "password": password,
    },
  );

  if (response.statusCode == 200) {
    Map<String, dynamic> body = json.decode(response.body);
    return Data.fromJson(body);  // Adjust this according to your Data model
  }

  throw Exception('Some Error Occurred');
}

让我们看看结果。

如果有帮助请告诉我。