默认情况下,webpack打包js不会做任何转换和编译 而至原样输出,所以让浏览器支持es高级语法需要用babel来转换。
javascript
npm install --save-dev @babel/preset-env
@babel/core
babel-loader
javascript
webpack.config.js
const miniCssExtractPlugin = require('mini-css-extract-plugin')
module.exports = {
entry: './src/index.js',
output: {
filename: 'main.js',
},
mode: 'development', // 或者 'production'
module: {
rules: [
{
test: /\.js/,
exclude: /(node_modules)/,
use: {
loader: 'babel-loader',
options: {
presets: ['@babel/preset-env']
}
}
}
]
}
}
javascript
src/index.js
const fn = (a) => {
console.log('fn')
return a+1
}
fn(2)
const promise = () => {
return new Promise((resolve, reject) => {
setTimeout(() => {
console.log('promise')
resolve('success')
}, 2000);
})
}
(async()=>{
await promise()
console.log('aaa')
})()