webpack-papa-script/bin/util/concatFile.js

A frontend projects solution

/**
 * Created by Nonjene on 2017/7/12.
 */

const UglifyJS = require('uglify-js');
const fs = require('fs');
//const md5File = require('md5-file');

/*function concatCommon(aFileList, sTo) {
    return new Promise((resolve, reject) => {
        concat(aFileList, sTo, function(err) {
            if (err) return reject(err);
            resolve();
        });
    });
}*/

const reduceList = aFileList =>
  aFileList.reduce((host, item) => {
    host[item] = fs.readFileSync(item, 'utf8');
    return host;
  }, {});

function compress(aFileList, sTo) {
  if(!Array.isArray(aFileList) || aFileList.length<1){
    return Promise.reject('');
  }
  const res = UglifyJS.minify(reduceList(aFileList), {
    ie8: true
  });

  /* istanbul ignore if */
  if (res.error) {
    return Promise.reject(
      `文件合成错误：${sTo}\n⚠️ 注意：合并的js不能包含es6语法。\n${JSON.stringify(
        res.error
      ).replace(/,/g, ',\n')}`
    );
  }

  fs.writeFileSync(sTo, res.code, 'utf8');
  return Promise.resolve();
}

module.exports = function(aFileList, sTo) {
  //await concatCommon(aFileList, sTo);
  return compress(aFileList, sTo);
};