webpack-自定义plugin

##copyright-webpack-plugin

class CopyrightWebpackPlugin {
    constructor(options){
        console.log(options)
    }
    apply(compiler){
        //官网有很多钩子，我们以emit为例
        compiler.hooks.emit.tapAsync(//异步操作的例子
            "CopyrightWebpackPlugin",
            (compilation,cb) => {
                compilation.assets["copyright.txt"] = {  //打包后创建一个新文件 打包后会在dist下多一个copyright.txt文件  内容为 hello copy
                    source:function(){
                        return "hello copy"
                    },
                    size:function(){
                        return 20;
                    }
                };
                cb()
            }
        )
        //同步的例子
        compiler.hooks.compile.tap(
            "CopyrightWebpackPlugin",
            compilation => {
                console.log("开始了")
            }
        )
    }
}

module.exports = CopyrightWebpackPlugin

##webpack.config.js

const copyrightWebackPlugin = require(‘./myPlugins/copyright-webpack-plugin.js‘)

module.exports = {
    plugins:[
        new copyrightWebackPlugin({
            ‘name‘:‘Joy‘
        })
    ]
}