Webpack4 Entrypoint undefined = index.html

Question

使用 HtmlWebpackPlugin

const HtmlWebpackPlugin = require('html-webpack-plugin');module.exports = {
    plugins: [new HtmlWebpackPlugin()]
};

终端得到警告 
Entrypoint undefined = index.html

// 环境"webpack": "^4.12.0","html-webpack-plugin": "^3.2.0",

无论 dist 文件夹下是否有 index.html 文件