🖖 vue2 retrofit ⚡️ Viet-2.0

preface

I wrote that beforevite 与 vue2Integrated articles, just call him🖖 Vue2. X retrofit ⚡️ Vite – 1.0
Time flies, more than a month has passed and a certain degree of accumulation of a part of the new posture, need to1.0Make some improvements and additions; Then write the2.0
2.0Mainly forviteIntegrate and do somethingMining pit guide, and1.0It doesn’t matterPlease eat directly

📢 Note: It is only recommended to run vite in development mode in the production environment as before; Webpack, after all, is more sophisticated in packaging

Project background

The transformation project is a very important, iterative and frequent system of the company; It now has over 100 pages
Engineering formwork by@vue/cliTo create thevue2.xVersion for internal usewebpack4.xbuild
As projects get bigger (50 pages per year or so), the need for a cold start becomes more pressing

Technical analysis

While Vite is growing fast, NPM plugins for Vite are also catching on fast; But there was always something out of reach in our old projects
Here I mainly with my actual transformation of the problems encountered to do the technical summary, if you have encountered other problems in the process of use, this article to solve the problem ideas also have a certain reference value
The following are the transformation problems I encountered (for vue2 project generated by @vue/ CLI)
1. The default project root directory entry is requiredindex.htmlPoint to existingpublic/index.html
2. Convert CSS notation@import '~normalize.css/normalize.cssIn the~The alias
3. eliminateimport('@/pages/' + path)Written in vite warning ⚠️
4. conversionrequire 为 importSyntax —- CommonJs to ESModule
5. The compatible webpackrequire.contexgrammar
6. support<script>Write in code blockjsxSyntax —- render returns JSX

vite plugins

First, the project was modified based on an official plugin, Vite-plugin-vue2
```
npm i -D vite-plugin-vue2
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```
You might want to know how to write a Vite plugin first

Point index.html to public/index.html

Plug-in vite – plugin – HTML – the template

npm i -D vite-plugin-html-template
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Quote from vite’s official website

You may have noticed that in a Vite project, index.html is in the outermost layer of the project instead of in the public folder. This is intentional: Vite is a server during development, and index.html is the entry file for that Vite project.
The principle of analytic
1. In development modeviteAll resources are passedhttp serverReturn to before browsingindex.htmlThere is no exception
This means that we can intercept/and /index.html requests through the plugin’s configureServer and then read public/index.html and return it
```
{
  name: 'vite-vue2:html'.configureServer(server) {
    server.middlewares.use((req, res, next) = > {
      // Intercepts/or /index.html requests
      if (req.url === '/' || req.url === '/index.html') {
        const html = fs.readFileSync(path.join(__dirname, 'public/index.html'), 'utf8')
        / / return public/index. HTML
        res.end(html)
      } else {
        next()
      }
    })
  },
}
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```
1. In build mode we need to touch a new concept virtual file
- Official Demo 👉 introduces a virtual file
- We use load to properly load public/index.html in build mode
```
{
  name: 'vite-vue2:html'.load(id) {
    if (id.endsWith('index.html')) {
      const html = fs.readFileSync(path.join(__dirname, 'public/index.html'), 'utf8')
      / / return public/index. HTML
      return html
    }
  },
}
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```
- XDM might say why not load index.html via config.root;
- The root directory of the vue2 project is the source directory, and index. HTML appears as source code, not as a static file
- Changing config.root to public causes many other problems; For example, @/views/home.vue is intended to find/SRC /views/home.vue
- 👉 index.html is the entry file for the Vite project

Convert CSS notation`@import '~normalize.css/normalize.css`In the`~`The alias

This is aviteMore powerful parts, support the use ofresolve.alias Official note 👉 Vite path aliases also comply with CSS

Pit!!!!!!: only recognizealias/xxxxDon’t recognizealiasxxxx

You have the following configuration

  {
    resolve: {
      alias: {
        The '@': path.join(__dirname, 'src'),
        '~': path.join(__dirname, 'node_modules'), // This is usually used for CSS import}}}Copy the code

They will be@/xxxx,~/xxxxHit,But not by @xxxx,~xxxxhit
A lot of people have this when they write CSS@import '~normalize.css/normalize.css'; —- This inability to hit

You need to write it like this

  resolve: {
    alias: [
      // For @xxxx and @/ XXXX
      { find: The '@'.replacement: path.join(__dirname, 'src')},/ / ~ / XXXX
      { find: ~ / / * * // ^ ~? = \ /), replacement: path.join(__dirname, 'node_modules')},/ / ~ XXXX
      { find: / * ~ * // ^ ~? ! / / /), replacement: path.join(__dirname, 'node_modules/')},]},Copy the code

eliminate`import('@/pages/' + path)`Written in vite warning ⚠️

Plug-in vite – plugin – dynamic – import

npm i -D vite-plugin-dynamic-import
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So this is kind of a tricky one, and there are two things to think about
1. @This alias replacement —- vite reported an error
2. pathDynamic path analysis —- vite warning

The principle of analytic

impot('@/pages/' + path)You essentially enumerate all the files under Pages and generate oneswitchTo provide matching

If the directory structure is as follows:

├ ─ ─ SRC / | ├ ─ ─ pages / | | ├ ─ ─ foo vue | | ├ ─ ─ bar / | | | ├ ─ ─ index. The vue | ├ ─ ─ routes. The tsCopy the code

// src/routes.ts
function load(path) {
  return import('@/pages/' + path)
}

const routes = [
  {
    name: 'foo'.path: '/foo'.component: () = > load('foo'),}, {name: 'bar'.path: '/bar'.component: () = > load('bar'),},]Copy the code

Will generate:

function load(path) {
  return __variableDynamicImportRuntime__('@/pages/' + path)
}

const routes = [
  {
    name: 'foo'.path: '/foo'.component: () = > load('foo'),}, {name: 'bar'.path: '/bar'.component: () = > load('bar'),},]// List all possible paths
function __variableDynamicImportRuntime__(path) {
  switch (path) {
    case './pages/foo': return import('./pages/foo.vue');
    case './pages/foo.vue': return import('./pages/foo.vue');
    case './pages/bar': return import('./pages/bar/index.vue');
    case './pages/bar/index': return import('./pages/bar/index.vue');
    case './pages/bar/index.vue': return import('./pages/bar/index.vue'); }}Copy the code

See the dynamic-import-vars link

conversion`require` 为 `import`grammar

Plug-in vite plugin — commonjs

npm i -D vite-plugin-commonjs
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The problem is CommonJs to ESModule, NPM found several packages do not implement my function (either do not convert, or inject environment variables error); Simply wrote a simplified version of their own, but also to broaden their technical line (can not eat ready-made, will do their own is not)
Technology selection
1. acornJs Abstract Syntax tree (AST) tool
2. acorn-walkSyntax tree traversal tool

The principle of analytic

Let’s use Acorn to convert the code toAST
Use acorn-walk to traverseASTParse out the file that require loads and convert it to import format

If there is code below

const pkg = require('.. /package.json');

const routers = [{
  path: '/foo'.component: require('@/pages/foo.vue').default;
}];
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Will generate:

import pkg  from ".. /package.json";
import _MODULE_default___EXPRESSION_object__ from "@/pages/foo.vue";

const routers = [{
  path: '/foo'.component: _MODULE_default___EXPRESSION_object__;
}];
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The compatible webpack`require.contex`grammar

Plug-in @ originjs/vite – plugin – the require – context
```
npm i -D @originjs/vite-plugin-require-context
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```
Consistent with vite’s built-in import.meta.globEager behavior

support`<script>`Write in code block`jsx`grammar

in@vue/cliThe configurationbabel.confg.jsYou can use it directlyjsx
invite-plugin-vue2Need to specify<script lang="jsx">

Complete configuration

Add in the project root directoryvite.config.ts

Note: The following configuration may need to be adjusted to suit your project

import path from 'path'
import { defineConfig } from 'vite'
Mandatory * Vite supports the official vue2 plug-in
import { createVuePlugin } from 'vite-plugin-vue2'
// Mandatory * Read public/index.html
import htmlTemplate from 'vite-plugin-html-template'
// Optional - compatible with CommonJs
import { vitePluginCommonjs } from 'vite-plugin-commonjs'
// Optional - compatible import('@views/' + path)
import { dynamicImport } from 'vite-plugin-dynamic-import'
// Optional - compatible with webpack require.contex
import viteRequireContext from '@originjs/vite-plugin-require-context'

export default defineConfig({
  plugins: [
    createVuePlugin({
      jsx: true,})./** * webpack project require */
    vitePluginCommonjs(),
    /** * compatible with import('@views/' + path)
     */
    dynamicImport(),
    /** * require. Context in webpack project */
    viteRequireContext(),
    /** * Uses the public/index.html template */ by default
    htmlTemplate(),
  ],
  resolve: {
    alias: [{find: The '@'.replacement: path.join(__dirname, 'src')}, {find: ~ / / * * // ^ ~? = \ /), replacement: path.join(__dirname, 'node_modules')}, {find: / * ~ * // ^ ~? ! / / /), replacement: path.join(__dirname, 'node_modules/')},].// Same as extensions in Webpack
    extensions: ['.vue'.'.js'.'.jsx'.'.ts'.'.tsx'.'.json'],},define: {
    / / with webpack DefinePlugin
    'process.env': process.env,
  }
})

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run

Add the packge.json scripts command

{
  "scripts": {
+ "vite": "export NODE_ENV=development; vite"}}Copy the code

npm run vite

🎉 Boom shakalaka!!!

preface

Project background

Technical analysis

vite plugins

Point index.html to public/index.html

Convert CSS notation@import '~normalize.css/normalize.cssIn the~The alias

eliminateimport('@/pages/' + path)Written in vite warning ⚠️

conversionrequire 为 importgrammar

The compatible webpackrequire.contexgrammar

support<script>Write in code blockjsxgrammar

Complete configuration

run

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CSS text Styles

Convert CSS notation`@import '~normalize.css/normalize.css`In the`~`The alias

eliminate`import('@/pages/' + path)`Written in vite warning ⚠️

conversion`require` 为 `import`grammar

The compatible webpack`require.contex`grammar

support`<script>`Write in code block`jsx`grammar