使用webpack plugin（webpack 3）

  1. 遍历得到图片文件名
  2. 把用到的文件放入对象中，属性值设置为true
  3. 读取文件，并删除掉 ```javascript function MyPlugin() {} var fs = require(‘fs’); var path = require(‘path’);

function readFileList(dir, filesList = []) { const files = fs.readdirSync(dir); files.forEach((item, index) => { var fullPath = path.join(dir, item); const stat = fs.statSync(fullPath); if (stat.isDirectory()) { readFileList(path.join(dir, item), filesList); //递归读取文件 } else { filesList.push(item); } }); return filesList; }

var filesList = []; var obj = {} readFileList(path.resolve(__dirname, ‘../src/assets/img’), filesList); MyPlugin.prototype.apply = function (compiler) { compiler.plugin(‘emit’, function (compilation, callback) { for (let file of filesList) { obj[file] = false }

  1. compilation.chunks.forEach(function (chunk) {
  2.   chunk.files.forEach(function (filename) {
  3.     // Get the asset source for each file generated by the chunk:
  4.     var source = compilation.assets[filename].source();
  5.     for (let file of filesList) {
  6.       if (source.includes(file)) {
  7.         obj[file] = true
  8.       }
  9.     }
  10.     fs.writeFileSync('write.txt', JSON.stringify(obj))
  11.   });
  12. });
  14. callback();

}); };

module.exports = MyPlugin;

  1. <a name="ceMYP"></a>
  2. ### 在配置文件中引用
  3. ```javascript
  4. const FilterImg = require('./filterImg')
  5. plugins: [
  6.   new FilterImg()
  7. ]

删除文件：直接用node运行

  1. // remove.js
  2. const fs = require('fs')
  3. const path = require('path')
  6. function removefile(dir, filesList = []) {
  7.     const files = fs.readdirSync(dir);
  8.     files.forEach((item, index) => {
  9.         var fullPath = path.join(dir, item);
  10.         const stat = fs.statSync(fullPath);
  11.         if (stat.isDirectory()) {
  12.             removefile(path.join(dir, item), filesList); //递归读取文件
  13.         } else {
  14.             if (!filesList[item] && item !== '.DS_Store') {
  15.                 fs.unlinkSync(fullPath);
  16.             }
  17.         }
  18.     });
  19. }
  21. try {
  22.     const data = fs.readFileSync(path.join(__dirname, 'write.txt'), 'utf8')
  23.     removefile(path.resolve(__dirname, './src/assets/img'), JSON.parse(data))
  24. } catch (err) {
  25.     console.error(err)
  26. }