向 API 端点发送发布请求时出错

Question

我正在学习一本关于 MERN 项目的书，在测试源代码时遇到了这个问题。

我有这个代码：

/config.config.js

const config = {
    env: process.env.NODE_ENV || 'development',
    port: process.env.PORT || 3000,
    jwtSecret: process.env.JWT_SECRET || "YOUR_secret_key",
    mongoUri: process.env.MONGODB_URI ||
      process.env.MONGO_HOST ||
      'mongodb://' + (process.env.IP || 'localhost') + ':' +
      (process.env.MONGO_PORT || '27017') +
      '/mernproject'   }
export default config

/server/controllers/user.controller.js

import User from '../models/user.model'
import extend from 'lodash/extend'
import errorHandler from '../helpers/dbErrorHandler'

const create = async (req, res, next) => {
    const user = new User(req.body)
    try {
        await user.save()
        return res.status(200).json({
            message: "Succesfully signed up!"
        })
    } catch (err) {
        return res.status(400).json({
            error: errorHandler.getErrorMessage(err)
        })
    }
}

export default {create}

/helpers/dbErrorHandlers.js

const getErrorMessage = (err) => {
    let message = ''
    if (err.code) {
        switch (err.code) {
            case 11000:
            case 11001:
                message = getUniqueErrorMessage(err)
                break
            default:
                message = 'Something went wrong'
        }
    }
    else {
        for (let errName in err.errors) {
            if (err.errors[errName].message)
            message = err.erros[errName].message
        }
    }
    return message
}

const getUniqueErrorMessage = (err) => {
    let output
    try {
        let fieldName = 
        err.message.substring(err.message.lastIndexOf('.$') + 2,
        err.message.lastIndexOf('_1'))
        output = fieldName.chartAt(0).toUpperCase() + fieldName.slice(1) +
        ' already exists'
    } catch (ex) {
        output = 'Unique field already exists'
    }
    return output
}

export default {getErrorMessage}

/models/user.model.js

import mongoose from 'mongoose'

const UserSchema = new mongoose.Schema({
    name: {
        type: String,
        trim: true,
        required: 'Name is required'
    },

    email: {
        type: String,
        trim: true,
        unique: 'Email already exists',
        match: [/.+\@.+\..+/, 'Please fill a valid email address'],
        required: 'Email is required'
    },

    created: {
        type: Date,
        default: Date.now
    },

    updated: Date,

    hashed_password: {
        type: String,
        required: "Password is required"
    },
    
    salt: String
})

UserSchema
    .virtual('password')
    .set(function(password) {
        this._password = password
        this.salt = makeSalt()
        this.hashed_password = this.encryptPassword(password)
    })
    .get(function() {
        return this._password
    })

UserSchema.path('hashed_password').validate(function(v) {
    if (this._password && this._password.length < 6) {
        this.invalidate('password', 'password must be at least 6 characters.')
    }
    if (this.isNew && !this._password) {
        this.invalidate('password', 'Password is required')
    }
}, null)

UserSchema.methods = {
    authenticate: function(plainText) {
        return this.encryptPassword(plainText) === this.hashed_password
    },
    encryptPassword: function(password) {
        if (!password) return ''
        try {
            return crypto
            .createHmac('sha1', this.salt)
            .update(password)
            .digest('hex')
        } catch (err) {
            return ''
        }
    },
    makeSalt: function() {
        return Math.round((new Date().valueOf() * Math.random())) + ''
    }
}

export default mongoose.model('User', UserSchema)

/routes/user.routes.js

import express from 'express'
import useCtrl from '../controllers/user.controller'
import authCtrl from '../controllers/auth.controller'

const router = express.Router()

router.route('api/users')
    .get(useCtrl.list)
    .post(useCtrl.create)

router.route('/api/users/:userId')
    .get(authCtrl.requireSignin, useCtrl.read)
    .put(authCtrl.requireSignin, authCtrl.hasAuthorization, useCtrl.update)
    .delete(authCtrl.requireSignin, authCtrl.hasAuthorization, useCtrl.remove)

router.param('userId', useCtrl.userByID)

export default router

/server.js

import config from './../config/config'
import app from './express'
import mongoose from 'mongoose'

mongoose.Promise = global.Promise
mongoose.connect(config.mongoUri, { useNewUrlParser: true, useCreateIndex: true, useUnifiedTopology: true } ) 

mongoose.connection.on('error', () => {
  throw new Error(`unable to connect to database: ${mongoUri}`)
})

app.listen(config.port, (err) => {
  if (err) {
    console.log(err)
  }
  console.info('Server started on port %s.', config.port)
})

问题是在测试对 API 端点的 post 请求时，我收到“错误 404 未找到”。数据库 (mernproject) 和模型 (Users) 在 mongodb 中成功创建。我需要帮助来解决这个问题。提前致谢。