@blastz/logger NPM

Logger

Node.js logger based on winston.

Install

$ npm install @blastz/logger

Usage

import { logger, LoggerLevel, createConsoleTransport } from "@blastz/logger";

logger.clear().add(createConsoleTransport());

logger.info("hello world!");

Logging levels

The logger support six loggin levels

const levels = {
  fatal: 0,
  error: 1,
  warn: 2,
  info: 3,
  debug: 4,
  trace: 5,
};

Console transport

Call createConsoleTransport method to create console transport.

Console transport will output logs with such format

2021-05-14T06:30:02.421Z  INFO
{
  message: 'test',
  hostname: 'OMEN',
  pid: 32684
}

File transport

Call createFileTransport to create file transport

logger
  .clear()
  .add(createFileTransport({ level: LoggerLevel.Trace }))
  .add(createFileTransport({ level: LoggerLevel.Error }));

It will create two folds error and trace

log
- error
- trace

The error fold will include loggin files that logging level is above error, and trace fold will include loggin files above trace.

File transport will log with json format

{"message":"trace","level":"trace","hostname":"OMEN","pid":762,"timestamp":"2021-05-14T06:51:59.894Z"}

All options in winston-daily-rotate-file are supported by function options.

Custom metadatas

When you need some custom metadatas, like trace id. you can pass AsyncLocalStorage to the logger context.

const context = new AsyncLocalStorage<Record<string, unknown>>();

logger.context = context;

logger.clear().add(createConsoleTransport());

store.run({ traceId: "xxx" }, () => {
  logger.info("test");
});

The console ouput will include traceId property.