wechat-lite/wxapp/pack.js

wechat js api

const fs = require('fs');
const path = require('path');
const glob = require('glob');

const pack = (dir, options) => {
  options = Object.assign({
    nodir: true
  }, options);
  const files = glob
    .sync(`${dir}/**`, options)
    .map(filename => {
      const data = fs.readFileSync(filename);
      return {
        data,
        filename
      };
    });
  let datas = [], offset = 18 + (12 * files.length);
  const names = files.map(({ filename, data }) => {
    filename = path.relative(dir, filename);
    const name = new Buffer.from(`/${filename.replace(/\\/g, '/')}`);
    offset += name.length;
    datas.push(data);
    return name;
  });
  let metas = Buffer.concat(names.map((name, i) => {
    const data = datas[i];
    const meta = Buffer.concat([
      $(name.length, 4),
      name,
      $(offset, 4),
      $(data.length, 4)
    ]);
    offset += data.length;
    return meta;
  }));
  datas = Buffer.concat(datas);
  metas = Buffer.concat([
    $(files.length, 4)
  ].concat(metas));
  const header = Buffer.concat([
    $(0xBE),
    $(0x01, 4),
    $(metas.length, 4),
    $(datas.length, 4),
    $(0xED)
  ]);
  return Buffer.concat([header, metas, datas]);
};

const $ = (v, u = 1) => {
  const buffer = Buffer.alloc(u);
  switch (u) {
    case 1: buffer.writeUIntLE(v, 0, 1); break;
    case 4: buffer.writeUInt32BE(v); break;
  }
  return buffer;
};

module.exports = pack;