vue項目中使用mock模拟後端資料

前言

使用mock可以讓前端不在局限于後端接口，在規定好文檔格式後甚至能一次性開發完整個前端接口，大大節省了對接時間，可以說是目前前端必備的技能之一了。最近做新項目，重新搭建了下架構，想着寫一篇mock的配置文章，讓大家共同進步。

一、npm下載下傳插件

npm install mockjs --save-dev
           

二、建立mock檔案夾

1.在跟目錄(src目錄同級)下建立mock檔案夾

2.mock檔案夾下建立index.js檔案

import Mock from 'mockjs'
import { param2Obj } from '../src/utils'

import user from './user'

const mocks = [
  ...user
]

// for front mock
// please use it cautiously, it will redefine XMLHttpRequest,
// which will cause many of your third-party libraries to be invalidated(like progress event).
export function mockXHR() {
  // mock patch
  // https://github.com/nuysoft/Mock/issues/300
  Mock.XHR.prototype.proxy_send = Mock.XHR.prototype.send
  Mock.XHR.prototype.send = function() {
    if (this.custom.xhr) {
      this.custom.xhr.withCredentials = this.withCredentials || false

      if (this.responseType) {
        this.custom.xhr.responseType = this.responseType
      }
    }
    this.proxy_send(...arguments)
  }

  function XHR2ExpressReqWrap(respond) {
    return function(options) {
      let result = null
      if (respond instanceof Function) {
        const { body, type, url } = options
        // https://expressjs.com/en/4x/api.html#req
        result = respond({
          method: type,
          body: JSON.parse(body),
          query: param2Obj(url)
        })
      } else {
        result = respond
      }
      return Mock.mock(result)
    }
  }

  for (const i of mocks) {
    Mock.mock(new RegExp(i.url), i.type || 'get', XHR2ExpressReqWrap(i.response))
  }
}

// for mock server
const responseFake = (url, type, respond) => {
  return {
    url: new RegExp(`${process.env.VUE_APP_BASE_API}${url}`),
    type: type || 'get',
    response(req, res) {
      console.log('request invoke:' + req.path)
      res.json(Mock.mock(respond instanceof Function ? respond(req, res) : respond))
    }
  }
}

export default mocks.map(route => {
  return responseFake(route.url, route.type, route.response)
})
           

// '../src/utils'
export function param2Obj(url) {
  const search = url.split('?')[1]
  if (!search) {
    return {}
  }
  return JSON.parse(
    '{"' +
      decodeURIComponent(search)
        .replace(/"/g, '\\"')
        .replace(/&/g, '","')
        .replace(/=/g, '":"')
        .replace(/\+/g, ' ') +
      '"}'
  )
}
           

 3.mock檔案夾下建立mock-server.js檔案

const chokidar = require('chokidar')
const bodyParser = require('body-parser')
const chalk = require('chalk')
const path = require('path')

const mockDir = path.join(process.cwd(), 'mock')

function registerRoutes(app) {
  let mockLastIndex
  const { default: mocks } = require('./index.js')
  for (const mock of mocks) {
    app[mock.type](mock.url, mock.response)
    mockLastIndex = app._router.stack.length
  }
  const mockRoutesLength = Object.keys(mocks).length
  return {
    mockRoutesLength: mockRoutesLength,
    mockStartIndex: mockLastIndex - mockRoutesLength
  }
}

function unregisterRoutes() {
  Object.keys(require.cache).forEach(i => {
    if (i.includes(mockDir)) {
      delete require.cache[require.resolve(i)]
    }
  })
}

module.exports = app => {
  // es6 polyfill
  require('@babel/register')

  // parse app.body
  // https://expressjs.com/en/4x/api.html#req.body
  app.use(bodyParser.json())
  app.use(bodyParser.urlencoded({
    extended: true
  }))

  const mockRoutes = registerRoutes(app)
  var mockRoutesLength = mockRoutes.mockRoutesLength
  var mockStartIndex = mockRoutes.mockStartIndex

  // watch files, hot reload mock server
  chokidar.watch(mockDir, {
    ignored: /mock-server/,
    ignoreInitial: true
  }).on('all', (event, path) => {
    if (event === 'change' || event === 'add') {
      try {
        // remove mock routes stack
        app._router.stack.splice(mockStartIndex, mockRoutesLength)

        // clear routes cache
        unregisterRoutes()

        const mockRoutes = registerRoutes(app)
        mockRoutesLength = mockRoutes.mockRoutesLength
        mockStartIndex = mockRoutes.mockStartIndex

        console.log(chalk.magentaBright(`\n > Mock Server hot reload success! changed  ${path}`))
      } catch (error) {
        console.log(chalk.redBright(error))
      }
    }
  })
}
           

4.mock檔案夾下建立user.js檔案

也就是在index.js中引入的模拟接口檔案，這裡已登陸接口為例

const tokens = {
  admin: {
    token: 'admin-token'
  },
  editor: {
    token: 'editor-token'
  }
}

export default [
  // user login
  {
    url: '/user/login',
    type: 'post',
    response: config => {
      const { username } = config.body
      const token = tokens[username]

      // mock error
      if (!token) {
        return {
          code: 60204,
          message: 'Account and password are incorrect.'
        }
      }

      return {
        code: 20000,
        data: token
      }
    }
  }
]
           

5.在main.js中引入

if (process.env.NODE_ENV === 'production') {
  const {
    mockXHR
  } = require('../mock')
  mockXHR()
}
           

 6.最後一步，也是最容易忘記的一步，在vue.config.js中寫入

module.exports = {
    ...
    devServer: {
        before: require('./mock/mock-server.js')
    }
    ...
}
           

總結

調用接口/user/login就就會執行mock的接口，傳回我們寫好的資料了。是不是很簡單，大家快去試試吧。

mock.js官網:http://mockjs.com/