winston.version '3.8.2' の出力に filenname, linenumber を付与

add-filenumber-to-winston.ts

import winston from "winston";

type LogLevel = keyof typeof winston.config.npm.levels;
const levels = Object.keys(winston.config.npm.levels);

const DEFAULT_LABEL = "-";

const formatAddLocation = winston.format((info) => {
  const getLocation = () => {
    const limitBak = Error.stackTraceLimit;
    Error.stackTraceLimit = Infinity;
    const stk = new Error().stack;
    Error.stackTraceLimit = limitBak;

    const lines = stk.split("\n");
    const msg = lines.slice(4).filter((x) => !x.includes("winston"))[0];
    const loc = msg.slice(msg.lastIndexOf("(") + 1, -1).replace("file://", "");
    const [filename, linenumber] = loc.split(":");
    return [filename, linenumber] as const;
  };

  info.location = getLocation();
  return info;
})();

export function getLoggerStandard(
  level: LogLevel,
  label: string = DEFAULT_LABEL
) {
  const logger = winston.createLogger({
    level: level as string,
    format: winston.format.combine(
      formatAddLocation,
      winston.format.label({ label: label }),
      winston.format.timestamp(),
      winston.format.colorize(),
      winston.format.printf(
        ({ level, message, label, timestamp, location }) =>
          `${timestamp} [${label || DEFAULT_LABEL}] ${level}: ${message} @${location[0]
          }:${location[1]}`
      )
    ),
    transports: [
      new winston.transports.Console({
        stderrLevels: levels,
      }),
    ],
  });

  return logger;
}

export function getLoggerAwsLambda(
  level: LogLevel,
  label: string = DEFAULT_LABEL
) {
  const logger = winston.createLogger({
    level: level as string,
    format: winston.format.combine(
      formatAddLocation,
      winston.format.label({ label: label }),
      winston.format.timestamp(),
      winston.format.json()
    ),
    transports: [new winston.transports.Console()],
  });

  return logger;
}

const defaultLogger = (() => {
  const level = (process.env.LOG_LEVEL || "info") as LogLevel;
  if (process.env.LAMBDA_TASK_ROOT) {
    return getLoggerAwsLambda(level);
  } else {
    return getLoggerStandard(level);
  }
})();

export default defaultLogger;