Unexpected token when trying to parse file

[matorodriguez]

Hi, I'm using Istanbul 0.4.5 with Mocha 5.2.0. I'm trying to test this code and I'm getting: "Error: Line 26: Unexpected token )" (the line with just: ),, after: pattern,):

const winston = require('winston');
const httpContext = require('express-http-context');
const uuidv1 = require('uuid/v1');

let logger;

const initialize = (app) => {
  // Assign a unique identifier to each request
  app.use(httpContext.middleware);
  app.use((req, res, next) => {
    httpContext.set('reqId', uuidv1().replace(/-/g, ''));
    return next();
  });

  const pattern = winston.format.printf((info) => {
    const reqId = httpContext.get('reqId');
    return `${info.timestamp};${info.level};${reqId ? `${reqId};` : ''}${info.message}`;
  });

  logger = winston.createLogger({
    level: 'debug',
    format: winston.format.combine(
      process.stdout.isTTY ? winston.format.colorize() : winston.format.uncolorize(),
      winston.format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss.SSSS' }),
      pattern,
    ),
    transports: [new winston.transports.Console()],
  });

  return logger;
};

const getLogger = () => (
  logger
);

module.exports = {
  initialize,
  getLogger,
};

Yes, it is solved taking off the comma from: "pattern,", but I think that the syntax is correct. I'm using ESLint too and, when I take off that comma, it says: "25:14 error Missing trailing comma comma-dangle". Thanks!