@licq/tpkg/index.js

pack or unpack wechatapp and qqminiapp package

const path = require("path");
const fs = require("fs");

/**
 * pack dir to pkg
 * @name pack
 * @param {pathLike} sourceDir [required] The directory to work with
 * @param {pathLike} targetPath [optional] The target path, The default path is the same as the sourceDir.
 * @param {string} targetName [optional] The target filename, The default name is the same as the sourceDir.
 * @since v1.0.0
 * @returns pathLike
 * @example
 * const tpkg = require('@licq/tpkg')
 * const res = tpkg.pack('path/to/dir/');
 * const res = tpkg.pack('path/to/dir/', 'path/to/dir/demo');
 * const res = tpkg.pack('path/to/dir/', 'path/to/dir/demo', 'demo.wxvpkg') // or demo.tqapkg
 * //==> eg: path/to/dir/demo.wxvpkg
 */
function pack(sourceDir, targetPath, targetName) {
  if (!fs.existsSync(sourceDir)) {
    return console.log(`\nsourceDir ${sourceDir} does not exist.\n`);
  }

  if(targetPath){
    if(!fs.existsSync(targetPath)){
      return console.log(`\ntargetPath ${targetPath} does not exist.\n`);
    }
  }else{
    targetPath = path.dirname(sourceDir);
  }

  if(!targetName){
    targetName = `${path.basename(sourceDir)}.wxvpkg`
  }

  targetPath = path.join(targetPath, targetName);
  

  const fd = fs.openSync(targetPath, "w");

  function writeSync(buf, start) {
    fs.writeSync(fd, buf, 0, buf.length, start);
  }

  function writeInt32(number, start) {
    let buf = Buffer.alloc(4);
    buf.writeInt32BE(number, 0);
    writeSync(buf, start);
  }

  let files = fs.readdirSync(sourceDir);
  let totalCount = files.length;
  let buf = Buffer.alloc(4);
  buf.writeInt32BE(totalCount, 0);
  writeSync(buf, 14);
  let start = 18;
  // 12 + /name.length
  let dataOffset = start;
  for (let file of files) {
    let name = `/${file}`;
    let buf = Buffer.from(name, "utf8");
    dataOffset = dataOffset + 12 + buf.length;
  }

  for (let file of files) {
    let nb = Buffer.from(`/${file}`, "utf8");
    // write filename byte length
    writeInt32(nb.length, start);
    start += 4;
    // write filename
    writeSync(nb, start);
    start += nb.length;
    // write offset
    writeInt32(dataOffset, start);
    start += 4;
    // write length
    let contentBuf = fs.readFileSync(path.join(sourceDir, file));
    writeInt32(contentBuf.length, start);
    start += 4;
    // write content
    writeSync(contentBuf, dataOffset);
    dataOffset += contentBuf.length;
  }

  fs.closeSync(fd);
  return targetPath;
}

/**
 * unpack pkg
 * @name unpack
 * @param {pathLike} pkgPath [required] The pkgPath to work with
 * @param {pathLike} targetPath [optional] The target path, The default is the same as the pkgPath.
 * @since v1.0.0
 * @returns pathLike
 * @example
 * const tpkg = require('@licq/tpkg')
 * const res = tpkg.unpack('path/to/dir/demo.wxvpkg', _dirname) // or demo.tqapkg
 * //==> eg: ${_dirname}/demo/**
 */
function unpack(pkgPath, targetPath) {
  if (!fs.existsSync(pkgPath)) {
    return console.log(`\npkgPath ${pkgPath} does not exist.\n`);
  }

  if (targetPath) {
    if (!fs.existsSync(targetPath)) {
      return console.log(`\ntargetPath ${targetPath} does not exist.\n`);
    }
  } else {
    targetPath = path.dirname(pkgPath);
  }

  targetPath = path.join(
    targetPath,
    path.basename(pkgPath, path.extname(pkgPath))
  );

  const fd = fs.openSync(pkgPath, "r");

  // read buffer
  function readSync(start, length) {
    const n = Buffer.alloc(length);
    fs.readSync(fd, n, 0, length, start);
    return n;
  }

  const totalCount = readSync(14, 4).readInt32BE(0);
  const map = {};
  let n = 18;
  for (let i = 0; i < totalCount; i++) {
    const e = {};
    // byte length of filename
    const i = readSync(n, 4).readInt32BE(0);
    n += 4;
    e.name = readSync(n, i).toString();
    n += i;
    e.offset = readSync(n, 4).readInt32BE(0);
    n += 4;
    e.length = readSync(n, 4).readInt32BE(0);
    n += 4;
    map[e.name] = e;
  }

  let created = [];
  for (let item of Object.values(map)) {
    let dir = path.join(targetPath, path.dirname(item.name));
    if (created.indexOf(dir) == -1) {
      fs.mkdirSync(dir, { recursive: true });
      created.push(dir);
    }
    let buf = readSync(item.offset, item.length);
    let filepath = path.join(targetPath, item.name);
    fs.writeFileSync(filepath, buf.toString("utf8"), "utf8");
  }

  fs.closeSync(fd);
  return targetPath;
}

module.exports = {
  pack,
  unpack,
};