Simple Express logger

Logger.js

function log(req, res, next) {
  var start = process.hrtime();
  var write = res.write;
  var end = res.end;
  var chunks = [];

  res.write = function newWrite(chunk) {
    chunks.push(chunk);

    write.apply(res, arguments);
  };

  res.end = function newEnd(chunk) {
    if (chunk) { chunks.push(chunk); }

    end.apply(res, arguments);
  };


  function logIt() {
    var diff = process.hrtime(start);

    console.log({
      date: new Date(),
      duration: diff[0] * 1e9 + diff[1],
      reqBody: req.body,
      resBody: Buffer.concat(chunks).toString('utf8'),
      path: req.originalUrl || req.url,
      method: req.method,
      status: res.statusCode
    });
  }

  res.once('finish', logIt);

  next();
}