与Webpack 4一起使用Webpack的Lodash不是TreeShaking吗？

Question

我想从生成的捆绑包中树摇动lodash以及我未使用的multiply功能webpack

我有2个主要文件app.js&math.js

它包含以下代码 -

app.js

import map from "lodash/map";

import { sum } from "./math";

console.log("");

console.log(`2 + 3 = ${sum(2, 3)}`);

map([1, 2, 3], x => {
    console.log(x);
});

math.js

export const sum = (a, b) => a + b;
export const multiply = (m, n) => m * n;

webpack.config.js

const path = require("path");
const webpack = require("webpack");
const UglifyJSPlugin = require("uglifyjs-webpack-plugin");
const Jarvis = require("webpack-jarvis");

let plugins = [new Jarvis()];

if (process.env.NODE_ENV === "production") plugins.push(new UglifyJSPlugin());

const config = {
    entry: "./app.js",
    output: {
        path: path.resolve(__dirname, "dist"),
        filename: "bundle.js"
    },
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /node_modules/,
                use: "babel-loader"
            }
        ]
    },
    plugins
};

module.exports = config;

我的npm脚本看起来像 -

"scripts": {
    "dev": "webpack --optimize-minimize --mode development",
    "dev:watch": "webpack --watch --optimize-minimize --mode development",
    "prod": "webpack -p --optimize-minimize --mode production",
    "prod:watch": "webpack -p --watch --optimize-minimize --mode production",
    "start": "npm run prod",
    "clean": "rm -rf dist"
  }

完整的代码可以在https://github.com/deadcoder0904/webpack-treeshake上找到

我尝试过使用UglifyJSPlugin但是在生成的包中它仍然显示我未使用的multiply函数math.js.此外,production从npm run prod遗骸产生的捆绑20kB很多,我也看到了很多lodash东西.

Answer 1

我找到了答案

要使用lodash树摇动,我们应首先安装lodash-es然后删除lodash依赖项

此外,它不应该首先编译,所以我们将.babelrc文件如下 -

{
  "presets": [
    [
      "env",
      {
        "modules": false
      }
    ]
  ]
}

请注意,该设置modules以false使得它不transpile

现在捆绑减少到16.2kB和5.79kB gzip

lodash仍然会使用模块中的某些代码,因为它需要lodash自行运行,而不是在结果包中添加该multiply函数./math.js

我还需要lodash-webpack-plugin才能正常工作

Treeshaking工作

我做了一些基本的回购解决了陈述的问题 -

https://github.com/deadcoder0904/webpack-exam

https://github.com/deadcoder0904/webpack-treeshake