spotify-manager/utils/logger.js

import path from "path";

import { createLogger, transports, config, format } from "winston";
import * as typedefs from "../typedefs.js";

const { combine, label, timestamp, printf, errors } = format;

const getLabel = (callingModule) => {
  if (!callingModule.filename) return "repl";
  const parts = callingModule.filename?.split(path.sep);
  return path.join(parts[parts.length - 2], parts.pop());
};

const allowedErrorKeys = ["name", "code", "message", "stack"];

const metaFormat = (meta) => {
  if (Object.keys(meta).length > 0)
    return "\n" + JSON.stringify(meta, null, "\t");
  return "";
}

const logFormat = printf(({ level, message, label, timestamp, ...meta }) => {
  if (meta.error) { // if the error was passed
    for (const key in meta.error) {
      if (!allowedErrorKeys.includes(key)) {
        delete meta.error[key];
      }
    }
    const { stack, ...rest } = meta.error;
    return `${timestamp} [${label}] ${level}: ${message}${metaFormat(rest)}\n` +
      `${stack ?? ""}`;
  }
  return `${timestamp} [${label}] ${level}: ${message}${metaFormat(meta)}`;
});

/**
 * Creates a curried function, and call it with the module in use to get logs with filename
 * @param {typedefs.Module} callingModule The module from which the logger is called (ESM - import.meta)
 */
export const curriedLogger = (callingModule) => {
  let winstonLogger = createLogger({
    levels: config.npm.levels,
    format: combine(
      errors({ stack: true }),
      label({ label: getLabel(callingModule) }),
      timestamp({ format: "YYYY-MM-DD HH:mm:ss" }),
      logFormat,
    ),
    transports: [
      new transports.Console({ level: "info" }),
      new transports.File({
        filename: import.meta.dirname + "/../logs/debug.log",
        level: "debug",
        maxsize: 10485760,
      }),
      new transports.File({
        filename: import.meta.dirname + "/../logs/error.log",
        level: "error",
        maxsize: 1048576,
      }),
    ]
  });
  winstonLogger.on("error", (error) => winstonLogger.error("Error inside logger", { error }));
  return winstonLogger;
}

export default curriedLogger;