Use Vue3 and Vite to achieve compatibility with lower version browsers

1. Configure Vite to support legacy browsers

Specify the build target

Vite supports newer browser versions by default. To be compatible with lower version browsers, you need to specify a lower build target in the (or) file. For example, you can set the target to es2015, a version that most modern browsers support.

export default defineConfig({
  build: {
    target: 'es2015'
  }
});

Use @vitejs/plugin-legacy plugin

@vitejs/plugin-legacyThe plugin is a plugin officially provided by Vite to enhance compatibility with older browsers. It can automatically handle some incompatible syntax and new APIs during the packaging process and generate corresponding polyfills for older browsers.

Install plug-in:

npm install @vitejs/plugin-legacy terser -D

existConfigure plug-ins:

import { defineConfig } from 'vite';
import vue from '@vitejs/plugin-vue';
import legacy from '@vitejs/plugin-legacy';

export default defineConfig({
  plugins: [
    vue(),
    legacy({
      // Here you can specify the browser version that needs to be compatible      targets: ['firefox < 59', 'chrome < 60'],
      // Other configuration options      additionalLegacyPolyfills: ['regenerator-runtime/runtime'],
      renderLegacyChunks: true,
      polyfills: [
        // List the polyfills that need to be added        '', '', '',
        'es/map', 'es/set', '',
        // ...Other polyfill      ]
    })
  ],
  // Other configurations...});

2. Use Babel for code translation

Although Vite itself has certain code translation capabilities, Babel, as a professional JavaScript compiler, can provide more flexible and powerful translation functions. You can integrate Babel in your Vite project to handle features or legacy browser compatibility that Vite does not support by default.

Install the necessary dependencies

npm install --save-dev @babel/core @babel/preset-env @vitejs/plugin-babel

Configure Babel

Create a project's root directory.babelrcFile (or directly inConfigure Babel in it) and add the following:

{
  "presets": [
    ["@babel/preset-env", {
      "targets": "defaults" // Or specify the specific browser version    }]
  ]
}

Or inConfiguration in:

import { defineConfig } from 'vite';
import vue from '@vitejs/plugin-vue';
import babel from '@vitejs/plugin-babel';

export default defineConfig({
  plugins: [
    vue(),
    babel({
      presets: [
        ['@babel/preset-env', {
          targets: "defaults" // Or specify the specific browser version        }]
      ]
    })
  ]
  // Other configurations...});

3. Testing and debugging

After completing the above configuration, you need to package the project and test it in a lower version of the browser. Ensure that the page can load and display normally and function normally. If you encounter problems, you can debug and repair them accordingly based on the error message.

4. Things to note

• Performance Considerations: While adding compatibility support can improve project compatibility, it may also increase packaged file size and runtime performance overhead. Therefore, when adding compatibility support, these factors need to be weighed.
• Continuous updates: With the update of browser versions and new features, you may need to regularly update your compatibility configuration and polyfill list to ensure that your project is consistently compatible with the latest browser versions.

Through the above steps and notes, you can implement compatibility support for lower version browsers in JavaScript projects built with Vite and Vue3.