Nock

HTTP requests mocking library for dart and flutter.

Nock can be used to test modules that perform HTTP requests in isolation.

Inspired by nock

Installing

Add dev dependency to your pubspec.yaml:

dev_dependencies:
  nock: ^1.2.3

Basic usage example:

import 'package:test/test.dart';
import 'package:http/http.dart' as http;
import 'package:nock/nock.dart';

void main() {
  setUpAll(() {
    nock.init();
  });

  setUp(() {
    nock.cleanAll();
  });

  test("example", () async {
    final interceptor = nock("http://localhost/api").get("/users")
      ..reply(
        200,
        "result",
      );

    final response = await http.get("http://localhost/api/users");

    expect(interceptor.isDone, true);
    expect(response.statusCode, 200);
    expect(response.body, "result");
  });
}

No mock found

if some request isn't mocked NetConnectionNotAllowed exception will be thrown:

void main() {
  test("example", () async {
    expect(
      http.get("http://localhost/api/users"),
      throwsA(TypeMatcher<NetConnectionNotAllowed>()),
    );
  });
}

API

Creating requests scope

final String baseUrl = "https://my-server.com";
final scope = nock(baseUrl);

Methods for creating interceptors

  • scope.get(dynamic url) -> Interceptor
  • scope.post(dynamic url, dynamic body) -> Interceptor
  • scope.put(dynamic url, dynamic body) -> Interceptor
  • scope.delete(dynamic url, dynamic body) -> Interceptor
  • scope.patch(dynamic url, dynamic body) -> Interceptor
  • scope.head(dynamic url, dynamic body) -> Interceptor

Using default base url

You could specify baseUrl for automatic scope usage:

void main(){
  setUpAll((){
    nock.defaultBase = "http://localhost/api";
    nock.init();
  });

  test("example", () async {
    nock.get("/users"); // create mock for GET http://localhost/api/users
  });
}

Url matching

You could use strings, regexp or any matcher from package:test:

final topicsInterceptor = nock.get("/topics")
  ..reply(200);

final usersInterceptor = nock.get(startsWith("/users"))
  ..reply(200);

final tagsInterceptor = nock.get(RegExp(r"^/tags$"))
  ..reply(200);

Specifying request headers

final interceptor = nock.get("/users")
  ..headers({
    'Session-Token': '59aff48f-369e-4781-a142-b52666cf141f',
  })
  ..reply(200);

Specifying request query string

Using query string:

final interceptor = nock.get("/users")
  ..query("ids[]=1&ids[]=2")
  ..reply(200);

Using example:

final interceptor = nock.get("/users")
  ..query({"id": 5})
  ..reply(200);

Using matchers:

final interceptor = nock.get("/users")
  ..query(startsWith("something"))
  ..reply(200);

final interceptor = nock.get("/users")
  ..query({'id': anyOf([1, 2, 3])})
  ..reply(200);

Using custom match function:

final interceptor = nock.get("/users")
  ..query((Map<String, List<String>> params) => true)
  ..reply(200);

// or

final interceptor = nock.get("/users")
  ..query((Map<String, String> params) => true)
  ..reply(200);

Specifying request body

Interceptor will parse HTTP request headers and try parse body.

Supported mime-types:

  • application/x-www-form-urlencoded
  • application/json
  • application/text
  • application/text

Using example:

final interceptor = nock.post(
    "/users",
    {
      "name": "John",
      "email": "john_doe@gmail.com",
    },
)
  ..reply(204);

Using matchers:

final interceptor = nock.post(
    "/users",
    {
      id: anyOf([1, 2, 3])
      name: any,
      email: TypedMather<String>(),
    },
)
  ..reply(204);

Using custom match function:

final interceptor = nock.post(
    "/users",
    (body) => body is Map,
)
  ..reply(204);

If you send binary data you could use custom raw match function:

final interceptor = nock.post(
    "/users",
    (List<int> body) => true,
)
  ..reply(204);

Specifying reply

application/json:

final interceptor = nock.get("/users")
  ..reply(200, [
    {
      "id": 1,
      "name": "John",
      "email": "john_doe@gmail.com",
    },
    {
      "id": 2,
      "name": "Mark",
      "email": "zuckerberg@gmail.com",
    },
  ]);

text/plain:

final interceptor = nock.get("/ping")
  ..reply(200, "pong");

Other binary data:

final interceptor = nock.get("/video")
  ..reply(200, <int>[73, 32, 97, 109, 32, 118, 105, 100, 101, 111]);

Specifying reply headers

Other binary data:

final interceptor = nock.get("/auth")
  ..reply(204, null, {
    "Session-Token": "59aff48f-369e-4781-a142-b52666cf141f",
  });

Persistent requests

To repeat responses for as long as nock is active, use .persist().

final users = nock.get("/users")
  ..persist()
  ..reply(
    200,
    "result",
  );

Note that while a persisted mock will always intercept the requests, it is considered "done" after the first interception.

Canceling pending mock:

users.cancel();

Do something after reply

final users = nock.get("/users")
  ..persist()
  ..reply(
    200,
    "result",
  )
  ..onReply(() => print("I'm done"));

Contributions Welcome!

Feel free to open PR or an issue

Libraries

nock