未捕获的错误节点Js

Question

So I am creating a test suite for my simple app...

I bump into some errors:

Server is running on port 3000
  POST /todos
    1) Uncaught error outside test suite
(node:5030) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): MongoError: failed to connect to server [localhost:27017] on first connect [MongoError: connect ECONNREFUSED 127.0.0.1:27017]
    2) "before each" hook for "should create a new todo"


  0 passing (2s)
  2 failing

  1)  Uncaught error outside test suite:
     Uncaught MongoError: failed to connect to server [localhost:27017] on first connect [MongoError: connect ECONNREFUSED 127.0.0.1:27017]
      at Pool.<anonymous> (node_modules/mongoose/node_modules/mongodb-core/lib/topologies/server.js:328:35)
      at Connection.<anonymous> (node_modules/mongoose/node_modules/mongodb-core/lib/connection/pool.js:274:12)
      at Socket.<anonymous> (node_modules/mongoose/node_modules/mongodb-core/lib/connection/connection.js:177:49)
      at emitErrorNT (net.js:1278:8)
      at _combinedTickCallback (internal/process/next_tick.js:74:11)
      at process._tickCallback (internal/process/next_tick.js:98:9)

  2)  "before each" hook for "should create a new todo":
     Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.


npm ERR! Test failed.  See above for more details.

Here's my test:

const expect = require('expect');
const request = require('supertest');
const {ObjectID} = require('mongodb');

const {app} = require('./../server');
const {Todo} = require('./../models/todo');

const todos = [{
  _id: new ObjectID(),
  text: 'First test todo'
}, {
  _id: new ObjectID(),
  text: 'Second test todo'
}];

beforeEach((done) => {
  Todo.remove({}).then(() => {
    return Todo.insertMany(todos);
  }).then(() => done());
});

describe('POST /todos', () => {
  it('should create a new todo', (done) => {
    var text = 'Test todo text';

    request(app)
      .post('/todos')
      .send({text})
      .expect(200)
      .expect((res) => {
        expect(res.body.text).toBe(text);
      })
      .end((err, res) => {
        if (err) {
          return done(err);
        }

        Todo.find({text}).then((todos) => {
          expect(todos.length).toBe(1);
          expect(todos[0].text).toBe(text);
          done();
        }).catch((e) => done(e));
      });
  });

  it('should not create todo with invalid body data', (done) => {
    request(app)
      .post('/todos')
      .send({})
      .expect(400)
      .end((err, res) => {
        if (err) {
          return done(err);
        }

        Todo.find().then((todos) => {
          expect(todos.length).toBe(2);
          done();
        }).catch((e) => done(e));
      });
  });
});

describe('GET /todos', () => {
  it('should get all todos', (done) => {
    request(app)
      .get('/todos')
      .expect(200)
      .expect((res) => {
        expect(res.body.todos.length).toBe(2);
      })
      .end(done);
  });
});

describe('GET /todos/:id', () => {
  it('should return todo doc', (done) => {
    request(app)
      .get(`/todos/${todos[0]._id.toHexString()}`)
      .expect(200)
      .expect((res) => {
        expect(res.body.todo.text).toBe(todos[0].text);
      })
      .end(done);
  });

  it('should return 404 if todo not found', (done) => {
    var hexId = new ObjectID().toHexString();

    request(app)
      .get(`/todos/${hexId}`)
      .expect(404)
      .end(done);
  });

  it('should return 404 for non-object ids', (done) => {
    request(app)
      .get('/todos/123abc')
      .expect(404)
      .end(done);
  });
});

And here's my server.js

var express = require('express');
var bodyParser = require('body-parser');
var {ObjectID} = require('mongodb');

var {mongoose} = require('./db/mongoose.js');
var {Todo} = require('./models/todo');
var {User} = require('./models/user');

var app = express();
const port = process.env.PORT || 3000;

app.use(bodyParser.json());

app.post('/todos', (req, res) =>{
  // console.log(req.body);
  var todo = new Todo({
    text: req.body.text
  });

  todo.save().then((doc) => {
    res.send(doc);
  }, (err) => {
    res.status(400).send(err);
  });
});

// GET /todos/12345
app.get('/todos/:id', (req, res) => {
  // req.send(req.params); - test localhost:3000/todos/123 on postman GET
  var id = req.params.id;

  // Validate id using isValid
 if(!ObjectID.isValid(id)){
     // Respond 404 and send back and an empty bodyParser
   return res.status(404).send();
 }


  // findById
Todo.findById(id).then((todo) =>{
if(!todo){
  return res.status(404).send();
}
res.send({todo});

}).catch((e) =>{
  res.status(400).send();
});


});

app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});

module.exports = {app};

Any idea what's causing my error

Most of the time its asking that it can't get all todos.

Please help!

Answer 1

Any idea what's causing my error

Somewhere, you have a promise that ultimately rejects, which you never hook up a rejection handler for (eg, catch or the second argument to then ). Exactly where that is is a matter of debugging, but for instance this code:

beforeEach((done) => {
  Todo.remove({}).then(() => {
    return Todo.insertMany(todos);
  }).then(() => done());
});

...has a promise you never hook up a rejection handler for. So if that promise rejects, you'll get the unhandled rejection error.

The actual problem may not be that specific one (though it does need a rejection handler), but if not it'll be another used the same way.

The rule is: Code must either handle promise rejections, or pass on the promise so they can be handled at the caller's level. If code doesn't pass on the promise (such as beforeEach above), it has to handle rejections.

Answer 2

Try adding this:

if(!module.parent){
 app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
 });
}