function _fetchEtag()

in src/providers/fs.js [44:73]

• 24 lines of code
• 3 McCabe index (conditional complexity)

  function _fetchEtag(pathname, stat) {
    return new Promise((resolve, reject) => {
      const cached = etagCache[pathname];
      if (cached && cached.timestamp === stat.mtime) {
        return resolve(cached.value);
      }

      // the file you want to get the hash
      const fd = fs.createReadStream(pathname);
      const hash = crypto.createHash("md5");
      hash.setEncoding("hex");

      fd.on("error", (err) => {
        reject(err);
      });

      fd.on("end", () => {
        hash.end();
        const etag = hash.read();
        etagCache[pathname] = {
          timestamp: stat.mtime,
          value: etag
        };
        resolve(etag);
      });

      // read all file and pipe it (write it) to the hash object
      return fd.pipe(hash);
    });
  }