Error: Error: connect ECONNREFUSED 127.0.0.1:80

Environment

Name	Version
msw	0.21.3
node	12.19.0
OS	MacOS

Request handlers

import { rest } from "msw";
import check1result from "./check1result";
import check2result from "./check2result";

function check1(queryParams: URLSearchParams): boolean {
  return true;
}

function check2(queryParams: URLSearchParams): boolean {
  return true;
}

const requestHandler = [
  rest.get("/api/resources", (req, res, ctx) => {
    let json;
    const queryParams = req.url.searchParams;

    if (check1(queryParams)) {
      json = ctx.json(check1result);
    } else if (check2(queryParams)) {
      json = ctx.json(check2result);
    }
    {
      json = ctx.json([]);
    }

    return res(ctx.delay(0), ctx.status(200), json);
  }),
];

const orderReturnMockServer = setupServer(...requestHandler);

// mws api server mock initialization
beforeAll(() =>
  orderReturnMockServer.listen({
    onUnhandledRequest: "error",
  })
);
afterAll(() => orderReturnMockServer.close());

describe('describe', () => {
    test('test1', () => {
        networkCall()
    })
    test('test2', () => {
        networkCall()
    })
})

Actual request

// Example of making a request. Provide your code here.
fetch('???').then((res) => res.json())

Current behavior

A lot of Error: Error: connect ECONNREFUSED 127.0.0.1:80 in the console logs when running my tests. But the tests pass most of the time. Sometimes there’s failures - for example timeouts. Not sure if it’s related to this though, just saying.

Expected behavior

No errors about connection refused in the console logs - as it looks like something’s wrong, but I don’t know what’s wrong and the tests pass too. 😕

Screenshots

I’ll paste some logs instead

console.error node_modules/@testing-library/react/dist/act-compat.js:52
      Error: Error: connect ECONNREFUSED 127.0.0.1:80
          at Object.dispatchError (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/jsdom/lib/jsdom/living/xhr/xhr-utils.js:62:19)
          at Request.<anonymous> (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/jsdom/lib/jsdom/living/xhr/XMLHttpRequest-impl.js:654:18)
          at Request.emit (events.js:326:22)
          at Request.onRequestError (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/request/request.js:877:8)
          at ClientRequestOverride.emit (events.js:314:20)
          at ClientRequest.<anonymous> (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/node-request-interceptor/src/interceptors/ClientRequest/ClientRequestOverride.ts:292:14)
          at ClientRequest.emit (events.js:314:20)
          at Socket.socketErrorListener (_http_client.js:428:9)
          at Socket.emit (events.js:314:20)
          at emitErrorNT (internal/streams/destroy.js:92:8) undefined


console.error node_modules/jsdom/lib/jsdom/virtual-console.js:29
      Error: Error: connect ECONNREFUSED 127.0.0.1:80
          at Object.dispatchError (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/jsdom/lib/jsdom/living/xhr/xhr-utils.js:62:19)
          at Request.<anonymous> (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/jsdom/lib/jsdom/living/xhr/XMLHttpRequest-impl.js:654:18)
          at Request.emit (events.js:326:22)
          at Request.onRequestError (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/request/request.js:877:8)
          at ClientRequestOverride.emit (events.js:314:20)
          at ClientRequest.<anonymous> (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/node-request-interceptor/src/interceptors/ClientRequest/ClientRequestOverride.ts:292:14)
          at ClientRequest.emit (events.js:314:20)
          at Socket.socketErrorListener (_http_client.js:428:9)
          at Socket.emit (events.js:314:20)
          at emitErrorNT (internal/streams/destroy.js:92:8) undefined


console.error node_modules/jsdom/lib/jsdom/virtual-console.js:29
      Error: Error: connect ECONNREFUSED 127.0.0.1:80
          at Object.dispatchError (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/jsdom/lib/jsdom/living/xhr/xhr-utils.js:62:19)
          at Request.<anonymous> (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/jsdom/lib/jsdom/living/xhr/XMLHttpRequest-impl.js:654:18)
          at Request.emit (events.js:326:22)
          at Request.onRequestError (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/request/request.js:877:8)
          at ClientRequestOverride.emit (events.js:314:20)
          at ClientRequest.<anonymous> (/Users/karuppiahn/projects/deda-group/S-OMS/s-oms-ui/node_modules/node-request-interceptor/src/interceptors/ClientRequest/ClientRequestOverride.ts:292:14)
          at ClientRequest.emit (events.js:314:20)
          at Socket.socketErrorListener (_http_client.js:428:9)
          at Socket.emit (events.js:314:20)
          at emitErrorNT (internal/streams/destroy.js:92:8) undefined

Something to add is, we do have some tests that get rid of components abruptly when they are in the middle of a fetch call (my assumption), which leads to a lot of the below logs

console.error node_modules/@testing-library/react/dist/act-compat.js:52
      Warning: Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in a useEffect cleanup function.
          in Orders (at Orders.test.tsx:121)
          in ThemeProvider (at Orders.test.tsx:120)
          in IntlProvider (at Orders.test.tsx:119)
          in Router (at Orders.test.tsx:118)
          in KeycloakProvider (at keycloak_mock_provider.tsx:46)
          in MockedKeycloakProvider (at Orders.test.tsx:117)

[slim-hmidi]

you are right. I added the different handlers mentioned by the warn and it works well now. thanks a lot for your time and your help.

[marcosvega91]

Hi @slim-hmidi your configuration seams right 😃 , Could I ask you to replace

beforeAll(() => {
  server.listen();
});

with

beforeAll(() => {
  server.listen({
    onUnhandledRequest: 'warn',
  })
});

and check then your console? Thanks, let me know