Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'Response'

Question

I am trying to get the JSON response from a server

 Future<dynamic> post(String path,
      {Map<String, dynamic>? params, String? token}) async {
    http.Response responseJson;
    try {
      var response = await http.post(
        getPath(path, null),
        body: json.encode(params),
        headers: {
          'Content-Type': 'application/json',
          'Authorization': 'Bearer $token',
        },
      );
      log(response.body);
      responseJson = _returnResponse(response);
    } on SocketException {
      throw const FormatException();
    }

    return responseJson;
  }

//returnResponse
 dynamic _returnResponse(http.Response response) {
    switch (response.statusCode) {
      case 200:
      case 201:
        var responseJson = json.decode(response.body.toString());
        return responseJson;
      case 400:
        throw BadRequestException();
      case 401:
      case 403:
        throw UnauthorisedException();
      case 404:
        throw NotFound();
      case 422:
        throw UnprocessableEntity();
      case 500:
        throw InternalServerError();
      default:
        throw FetchDataException();
    }
  }

But anytime I make the request, the request returns 200 successful but I get an Unhandled exception as below

E/flutter ( 8302): [ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'Response'
E/flutter ( 8302): #0      ApiClient.post
package:app/const/api_helper.dart:39

I have search through other simpler question, but nothing fixes my issue

this is the json format I am expecting

{
   "_id":"675676",
   "role":"user",
   "status":"active",
   "interest":[
      "Business"
   ],
   "name":"xyz",
   "email":"[email protected]",
   "phoneNumber":"123456677",
   "location":"Somewhere",
   "createdAt":"2020-04-18T08:16:23.976Z",
   "updatedAt":"2022-05-14T23:13:49.195Z",
   "__v":0,
   "id":"675676"
}

Can anyone help me figure out what's wrong?

Answer 1

responseJson is being declared as type http.Response. You can omit that entirely and just return the response from your method.

Future<dynamic> post(String path,
    {Map<String, dynamic>? params, String? token}) async {
  try {
    var response = await http.post(
      getPath(path, null),
      body: json.encode(params),
      headers: {
        'Content-Type': 'application/json',
        'Authorization': 'Bearer $token',
      },
    );
    log(response.body);
    return _returnResponse(response);
  } on SocketException {
    throw const FormatException();
  }
}