gruperly/apps/backend/src/logger.ts

import { AsyncLocalStorage } from 'node:async_hooks';
import pino from 'pino';
import pinoPretty from 'pino-pretty';

type LoggerEnvironment = {
  nodeEnv?: string;
};

type RequestLogContext = {
  requestId: string;
};

const requestLogContext = new AsyncLocalStorage<RequestLogContext>();

const prettyOptions = {
  colorize: true,
  translateTime: 'SYS:standard',
  ignore: 'pid,hostname',
};

const getLoggerEnvironment = (): LoggerEnvironment => ({
  nodeEnv: process.env.NODE_ENV,
});

const isDevelopmentEnvironment = (environment: LoggerEnvironment) =>
  environment.nodeEnv !== 'production';

const isTestEnvironment = (environment: LoggerEnvironment) => environment.nodeEnv === 'test';

export const runWithRequestLogContext = <T>(requestId: string, callback: () => T): T =>
  requestLogContext.run({ requestId }, callback);

const getRequestLogMetadata = () => {
  const context = requestLogContext.getStore();

  if (!context) {
    return {};
  }

  return { requestId: context.requestId };
};

export const createLoggerOptions = (environment: LoggerEnvironment): pino.LoggerOptions => ({
  enabled: !isTestEnvironment(environment),
  level: isDevelopmentEnvironment(environment) ? 'debug' : 'info',
  mixin: () => getRequestLogMetadata(),
  formatters: {
    level(label, number) {
      return {
        level: number,
        severity: label.toUpperCase(),
      };
    },
  },
});

export const createLogger = (
  environment: LoggerEnvironment = getLoggerEnvironment(),
) => {
  const options = createLoggerOptions(environment);
  if (isTestEnvironment(environment)) {
    return pino({ ...options, level: 'silent' });
  }

  if (isDevelopmentEnvironment(environment)) {
    return pino(options, pinoPretty(prettyOptions));
  }

  return pino(options);
};

export const logger = createLogger();