@wjunt/node-logger

Another simple logging for Node.js, which implements loglevel

Strongly recommend to use TypeScript

Usage

Note: Node.js>=8 is required.

ES6 module

import logger from '@wjunt/node-logger';

logger.info('info message');

CommonJS

const logger = require('@wjunt/node-logger').default;

logger.info('info message');

Documentation

The logger API is same as loglevel. Visit loglevel documentation for more details.

Basic logging method

• logger.trace(...msg: any[]): void;
• logger.debug(...msg: any[]): void;
• logger.info(...msg: any[]): void;
• logger.warn(...msg: any[]): void;
• logger.error(...msg: any[]): void;

Get new logger

Use getLogger to get new logger.

Example usage:

import logger, { Logger } from '@wjunt/node-logger';

const globalLogger = Logger.getLogger();

const logger1 = Logger.getLogger('new');
const logger2 = logger.getLogger('new');
const logger3 = logger1.getLogger('new');

When called with same name, getLogger method will return same instance of Logger. In this example, logger and globalLogger are same. Also logger1, logger2 and logger3.

Logger options

• level?: number | string A valid log level.
• noDefaultWriter?: boolean If set true, the default console writer will not be added.
• timeFormat?: string Define how time formatted, passed to writer constructor.
• traceFunction?: Function Base function to capture call stack, logger.trace by default.

Use logger writer

A ConsoleLoggerWriter is added by default, which write log message to stdout/stderr.

Use logger.addWriter(Writer: LoggerWriterConstructor, options?: LoggerWriterOptions): this to add customized writer.

Example usage:

import { FileLoggerWriter, Logger } from '@wjunt/node-logger';

const logger = Logger.getLogger('clean').addWriter(FileLoggerWriter);

logger.info('some message');

Here we get a logger with name 'clean', which output message to both console and file. FileLoggerWriter enables log-rotate by default. See more details at FileLoggerWriter

FileLoggerWriter

Output message to file.

Options

• dirname?: string Where log files stored, './logs' by default.
• rotateFormat?: false | string Format of rotated log files, 'YYYYMMDD' by default; if set false rotating will be disabled.
• timeFormat?: string YYYY-MM-DD HH:mm:ss.SSS by default.

ConsoleLoggerWriter

Output message to console.

Options

• timeFormat?: string HH:mm:ss.SSS by default.