Open handle keeps Jest from exiting ( TCPSERVERWRAP)

[lucianonooijen]

Error:

Jest has detected the following 1 open handle potentially keeping Jest from exiting:

● TCPSERVERWRAP

Env:

• Node 10
• Supertest 3.3.0
• Jest 23.6

Testcode:

const request = require('supertest');
const app = require('../app');

describe('Test the status paths', () => {
    test('The GET / route should give status code 200', async () => {
        expect.assertions(1);
        const response = await request(app).get('/');
        expect(response.statusCode).toBe(200);
    });

    test('The GET /status route should give status code 200', async () => {
        expect.assertions(1);
        const response = await request(app).get('/status');
        expect(response.statusCode).toBe(200);
    });
});

Full console output:

 PASS  tests/app.test.js
  Test if test database is configured correctly
    ✓ Jest should create a test database (54ms)
  Test the status paths
    ✓ The GET / route should give status code 200 (28ms)
    ✓ The GET /status route should give status code 200 (7ms)

Test Suites: 1 passed, 1 total
Tests:       3 passed, 3 total
Snapshots:   0 total
Time:        1.179s
Ran all test suites.

Jest has detected the following 1 open handle potentially keeping Jest from exiting:

  ●  TCPSERVERWRAP

      27 |     test('The GET /status route should give status code 200', async () => {
      28 |         expect.assertions(1);
    > 29 |         const response = await request(app).get('/status');
         |                                             ^
      30 |         expect(response.statusCode).toBe(200);
      31 |     });
      32 | });

      at Test.Object.<anonymous>.Test.serverAddress (node_modules/supertest/lib/test.js:59:33)
      at new Test (node_modules/supertest/lib/test.js:36:12)
      at Object.obj.(anonymous function) [as get] (node_modules/supertest/index.js:25:14)
      at Object.get (tests/app.test.js:29:45)

^C

[jonathansamines]

@lucianonooijen Does it works if you manually invoke app.close after each test? (either by individually calling it, or through a afterEach block)

[lucianonooijen]

@jonathansamines I tried adding

afterEach(() => app.close());

and

afterEach(app.close());

but both give the same error:

est the status paths › The GET /status route should give status code 200

    TypeError: app.close is not a function

       5 | const app = require('../app');
       6 |
    >  7 | afterEach(() => app.close());
         |                     ^
       8 |
       9 | describe('Test the status paths', () => {
      10 |     test('The GET / route should give status code 200', async() => {

      at Object.close (tests/supertest.test.js:7:21)

 FAIL  tests/supertest.test.js
  ● Test suite failed to run
    TypeError: app.close is not a function
       5 | const app = require('../app');
       6 |
    >  7 | afterEach(app.close());
         |               ^
       8 |
       9 | describe('Test the status paths', () => {
      10 |     test('The GET / route should give status code 200', async() => {

      at Object.close (tests/supertest.test.js:7:15)

Did I invoke them wrong or am I missing something somewhere?

[danielantelo]

+1 i could use help with this issue also, same env as above and same errors.

[jonathansamines]

@lucianonooijen @danielantelo Sorry about that, I sometimes confuse the express app with the server object.

When supertest is used in an express application not yet bound to a port, it will try to automatically bound it to a random port, holding a reference to the net server internally. To gain control over that process, you may want to try manually listen on a port yourself, so that you can close the connections manually.

let server, agent;

beforeEach((done) => {
    server = app.listen(4000, (err) => {
      if (err) return done(err);

       agent = request.agent(server); // since the application is already listening, it should use the allocated port
       done();
    });
});

afterEach((done) => {
  return  server && server.close(done);
});

it('description', async () => {
   // use agent instead of manually calling `request(app)` each time
   await agent.get('/some-path-relative-to-the-express-app')
});

As an alternative to setting up an agent, you can also use the end method to force supertest to close the automatic bound connection.

   // on each test
  it('the description', (done) => {
        request(app)
          .get('/some-path')
          .end(done);
  });

However, I am not sure how well this method plays with the promise based interface, because as you can see is expecting a callback.

References:
https://github.com/visionmedia/supertest/blob/master/lib/test.js#L54

Hope it helps!

[danielantelo]

thanks for the reply @jonathansamines , appreciate it! Still having issues tho.

This is my setupTestFrameworkScriptFile:

const request = require('supertest');
const Mockgoose = require('mockgoose').Mockgoose;
const app = require('./src/app');
const db = require('./db');
const fixtures = require('./tests/fixtures');

let server;

beforeEach(async () => {
  await db.connect(Mockgoose);
  await fixtures();
  server = await app.listen(4000);
  global.agent = request.agent(server);
});

afterEach(async () => {
  await server.close();
  await db.disconnect();
});

and then a test in another file:

describe('read', () => {
  test('lists all', async () => {
    const response = await global.agent.get('/get/all');
    expect(response.statusCode).toBe(200);
    expect(Array.isArray(response.body)).toBe(true);
    expect(response.body.length).toBe(3);
    expect(response.body).toMatchSnapshot();
  });
});

my tests pass, but jest does not exit due to open handles in global.agent.get('/get/all')

using .end() on the request does not work when using promises to assert values, i got the error superagent request was sent twice, because both .end() and .then() were called. Never call .end() if you use promises.

Any ideas what i am missing on the setup before/afters?

Much appreciated!

[jonathansamines]

@danielantelo @lucianonooijen Unless you are promisifying the server methods close and listen, that is unlikely to work, because they are expecting a callback and do not return a promise by default. You should either promisify those methods or use a callback based api

[danielantelo]

@jonathansamines you mean passing the done like in your example?

let server;

beforeEach((done) => {
    server = app.listen(4000, (err) => {
      if (err) return done(err);
       global.agent = request.agent(server);
       done();
    });
});

afterEach((done) => {
  return  server && server.close(done);
});

this is not solving it either

[jonathansamines]

@danielantelo What error are you getting while using the callback based api?

[danielantelo]

got it working with just jest/supertest/mongoose (removing mockgoose). Thanks for the help.

let server;

beforeAll(async (done) => {
  await mongoose.connect('mongodb://localhost:27017/testdb');
  server = app.listen(4000, () => {
    global.agent = request.agent(server);
    done();
  });
});

afterAll(async () => {
  await server.close();
  await mongoose.disconnect();
});

Now time to figure out the issue with mockgoose 😂

[skykanin]

got it working with just jest/supertest/mongoose (removing mockgoose). Thanks for the help.

let server;

beforeAll(async (done) => {
  await mongoose.connect('mongodb://localhost:27017/testdb');
  server = app.listen(4000, () => {
    global.agent = request.agent(server);
    done();
  });
});

afterAll(async () => {
  await server.close();
  await mongoose.disconnect();
});

Now time to figure out the issue with mockgoose 😂

This fix doesn't work if you have multiple test files. The server doesn't seem to be closing properly and you will get port collisions when trying to start the server in the different test files.

yarn run v1.10.1
$ jest --forceExit
 PASS  __tests__/routes/reviews.test.js
 FAIL  __tests__/routes/movies.test.js (6.343s)
  ● Console

    console.error node_modules/jest-jasmine2/build/jasmine/Env.js:157
      Unhandled error
    console.error node_modules/jest-jasmine2/build/jasmine/Env.js:158
      Error: listen EADDRINUSE :::5025
          at Object._errnoException (util.js:992:11)
          at _exceptionWithHostPort (util.js:1014:20)
          at Server.setupListenHandle [as _listen2] (net.js:1355:14)
          at listenInCluster (net.js:1396:12)
          at Server.listen (net.js:1480:7)

[danielantelo]

@skykanin you are right, after i got mockgoose working i realised that when i ran multiple files there was still an issue.

With mockgoose i had to close the connection after each test, otherwise would leave open handles on a single file. But doing that on the server just breaks things further.

So think we are now stuck on the same issue.

const request = require('supertest');
const mongoose = require('mongoose');
const Mockgoose = require('mockgoose').Mockgoose;
const app = require('./src/app');
const fixtures = require('./tests/fixtures');

const mockgoose = new Mockgoose(mongoose);
let server;

afterEach(async () => {
  await mockgoose.helper.reset();
  await fixtures();
});

beforeAll(async done => {
  await mockgoose.prepareStorage();
  await mongoose.connect('mongodb://testdb');
  await fixtures();
  server = app.listen(4000, () => {
    global.agent = request.agent(server);
    done();
  });
});

afterAll(async () => {
  if (server) {
    await server.close();
  }
  mongoose.connections.forEach(async con => {
    await con.close();
  });
  await mockgoose.mongodHelper.mongoBin.childProcess.kill();
  await mockgoose.helper.reset();
  await mongoose.disconnect();
});

Jest23 runs the first file, then fails to run any other files and gives lots of async timeout errors.

[jonathansamines]

@danielantelo Sorry, I am not familiar with the mockgoose library. Most I can do, is to ask a couple of questions:

Is mongoose.connections.forEach method an special kind of object which properly deals with async/await? If not, I would rather do something like:

    await Promise.all(mongoose.connections.map(con => con.close()))

Here I am assumming con.close is a promise returning function, otherwise, you would probably have to wrap it with a promise.

Also, is server.close a promise aware function? (it is natively not) If not, you will have to wrap it so that it properly awaits for the connection to close.

[kramerc]

Are you using Apollo Engine by any chance? I was able to solve this problem by disabling the engine in Apollo Server when testing.

[jalooc]

I'm not using Apollo Engine and I still get the same error. end() helps, but it forces me to use the uglier async handling style. Interestingly, the open handle is detected only for one post() request, out of many other requests I have in tests.

[ae-lexs]

I have the same issue:

Node version: 11.0.0
npm version: 6.5.0

package.json

{
  "name": "authentication",
  "version": "1.0.0",
  "description": "",
  "main": "server.js",
  "scripts": {
    "lint": "eslint --fix server.js src/**",
    "start": "node server.js",
    "start:dev": "nodemon server.js",
    "test": "jest --forceExit --detectOpenHandles"
  },
  "husky": {
    "hooks": {
      "post-pull": "npm install",
      "pre-commit": "npm run lint && npm test"
    }
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "bcrypt": "^3.0.3",
    "body-parser": "^1.18.3",
    "dotenv": "^6.2.0",
    "express": "^4.16.4",
    "jsonwebtoken": "^8.4.0",
    "lodash": "^4.17.11",
    "morgan": "^1.9.1"
  },
  "devDependencies": {
    "eslint": "^5.11.1",
    "eslint-plugin-node": "^8.0.1",
    "eslint-plugin-security": "^1.4.0",
    "husky": "^1.3.1",
    "jest": "^23.6.0",
    "nodemon": "^1.18.9",
    "prettier": "^1.15.3",
    "supertest": "^3.3.0"
  }
}

test task in package.json

  "scripts": {
    "test": "jest --forceExit --detectOpenHandles"
  },

app.test.js

const request = require('supertest');
const app = require('../app');

describe('App Request', () => {
  it('should responds with 404', () => {
    request(app)
      .get('/')
      .expect('Content-Type', /json/)
      .expect(404)
      .end((error, response) => {
        if (error) {
          return error;
        }

        return response;
      });
  });
});

Error:

> jest --forceExit --detectOpenHandles

 PASS  src/test/app.test.js
  App Request
    ✓ should responds with 404 (19ms)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        1.891s
Ran all test suites.

Jest has detected the following 1 open handle potentially keeping Jest from exiting:

  ●  TCPSERVERWRAP

       5 |   it('should responds with 404', () => {
       6 |     request(app)
    >  7 |       .get('/')
         |        ^
       8 |       .expect('Content-Type', /json/)
       9 |       .expect(404)
      10 |       .end((error, response) => {

      at Test.Object.<anonymous>.Test.serverAddress (node_modules/supertest/lib/test.js:59:33)
      at new Test (node_modules/supertest/lib/test.js:36:12)
      at Object.obj.(anonymous function) [as get] (node_modules/supertest/index.js:25:14)
      at Object.get (src/test/app.test.js:7:8)