Express JS Logging Boilerplate

logger.ts

import morgan, { StreamOptions } from "morgan";

import winston from "winston";

const levels = {
  error: 0,
  warn: 1,
  info: 2,
  debug: 3,
};

const level = () => {
  const env = process.env.NODE_ENV || "development";
  const isDevelopment = env === "development";
  return isDevelopment ? "debug" : "info";
};

const colors = {
  error: "red",
  warn: "yellow",
  info: "green",
  debug: "white",
};

winston.addColors(colors);

const format = winston.format.combine(
  winston.format.timestamp({ format: "YYYY-MM-DD HH:mm:ss:ms" }),
  winston.format.colorize({ all: true }),
  winston.format.printf(
    (info) => `${info.timestamp} ${info.level}: ${info.message}`
  )
);

const transports = [
  new winston.transports.Console(),
  new winston.transports.File({
    filename: "logs/error.log",
    level: "error",
  }),
  new winston.transports.File({ filename: "logs/debug.log", level: "info" }),
];

const Logger = winston.createLogger({
  level: level(),
  levels,
  format,
  transports,
});

const stream: StreamOptions = {
  write: (message) => Logger.debug(message),
};

const skip = () => {
  const env = process.env.NODE_ENV || "development";
  return env !== "development";
};

const morganMiddleware = morgan(
  ":method :url :status :res[content-length] - :response-time ms",
  { stream, skip }
);
export { Logger };
export default morganMiddleware;