未捕获的错误节点的js

Question

所以我创建一个测试套件，我简单的应用程序...

我碰到一些误区：

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. 

这里是我的测试：

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); 
    }); 
}); 

而且这里是我的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}; 

任何想法w帽子造成我的错误

大部分时间它的要求，它不能得到所有todos。

请帮忙！

Answer 1

任何想法是什么导致我的错误

某处，你有一个承诺，最终拒绝，你从来没有挂钩拒绝处理程序（例如，catch或第二个参数then）。正是那就是是调试的问题，但比如这个代码：

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

...有你从来没有挂钩的拒绝处理的承诺。所以如果这个承诺被拒绝，你会得到未处理的拒绝错误。

实际的问题可能不是那个特定的问题（尽管它确实需要一个拒绝处理程序），但是如果没有，它会以另一种方式使用。

规则是：代码必须处理承诺拒绝，或传递承诺，以便他们可以在调用者级别处理。如果代码没有通过承诺（如上面的beforeEach），它必须处理拒绝。

Answer 2

尝试添加此：

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