webpack4 安装语法转换器-Babel，且使用装饰器

插件

devDependencies

"babel-core": "^6.26.3",
"babel-loader": "^7.1.5",
"babel-plugin-transform-decorators-legacy": "^1.3.5",
"babel-polyfill": "^6.26.0",
"babel-preset-es2015": "^6.24.1",
"babel-preset-latest": "^6.24.1",

webpack.config.js

module: {
    rules: [
        {test: /\.js$/, use: 'babel-loader', exclude: /node_modules/}
    ]
}

新建配置文件 .babelrc

{
    "presets": ["es2015", "latest"],
    "plugins" : ["transform-decorators-legacy"]
}

坑

babel-loader，不能使用8.0.0；应该使用7.1.5