Swaler NPM | npm.io

Swaler

Swaler makes you easy and simple to log message in your web app, but not only that!

It has been developed on top of javascript console and support the following methods: .trace, .debug, .info, .warn, .error

Installation

npm install swaler

Usage

import {Logger} from 'swaler';

// A simple logger
const logger = new Logger();

logger.debug('Hello there!'); // Hello there!

// A logger with a Context
const loggerWithCtx = new Logger('Dalaran');

loggerWithCtx.debug('A new expansion has been detected...');
loggerWithCtx.info(`Time to go to Northrend.`);
loggerWithCtx.warn('Attention', 'to', 'take off!');
loggerWithCtx.error('A %s has been found!', 'crater');

// [Dalaran] A new expansion has been detected...
// [Dalaran] Time to go to Northrend.
// [Dalaran] Attention to take off!
// [Dalaran] A crater has been found!

Create a logger

// Several ways to create a logger
const logger = new Logger();
const logger = new Logger(context);
const logger = new Logger(null, opts);
const logger = new Logger(context, opts);

context

type: string

default: null

Give the logger a specific context that will be prompt between brackets

Very useful when, for examples, you want to log messages in some of your components without having to specify the component name each time you log something!

// Example using Context

import {Swaler} from 'swaler';

class AuthService {
  constructor() {
    this.logger = new Swaler('AuthService');
  }

  signIn() {
    // ... your awesome sign in implementation ...

    this.logger.info('User has successfully signed in!');
    // ... or maybe ...
    this.logger.error('An error occurred when trying to sign in user');
  }
}

// [AuthService] User has successfully signed in!
// [AuthService] An error occurred when trying to sign in user!

opts.level

type: SwalerLevel

default: null

Set the minimal level of log to display

import {Swaler, SwalerLevels} from 'swaler';

const logger = new Swaler(null, {level: SwalerLevels.WARN});

logger.debug("Won't be logged!");
logger.info("Won't be logged!");
logger.warn('Will be logged!');
logger.error('Will be logged!');

Log

All log methods are built on top of console which means that each Swaler log methods act the same way than console methods!

logger.trace

Display a trace log

logger.trace('A trace message');

logger.debug

Display a debug message

logger.debug('A debug message');

logger.info

Display an info message

logger.info('A info message');

logger.warn

Display a warn message

logger.warn('A warn message');

logger.error

Display a error message

logger.error('An error message');

Log with options

Sometimes, you may need to pass options when calling a log. To do so, use withLogOptions() methods

logger
  .withLogOptions({
    ignoreLevel: boolean,
  })
  .info('An info message with options');

Available options

options	Type	Description
ignoreLevel	boolean	Make the log ignoring the level of the logger

SwalerLogOptions.ignoreLevel

const logger = new Logger('AuthModule', {level: SwalerLevels.WARN});

logger
  .withLogOptions({ignoreLevel: true})
  .info('Will be logged despite the WARN levels!');

Misc

Swaler.defaultLevel

type: SwalerLevels

default: SwalerLevels.DEBUG

By default, all loggers will use the defaultLevel if you do not pass a opts.level.

import {Swaler, SwalerLevels} from 'swaler';

Swaler.defaultLevel =
  process.env.NODE_ENV === 'production'
    ? SwalerLevels.WARN
    : SwalerLevels.DEBUG;

const logger = new Swaler();
const loggerWithLevel = new Swaler(null, {level: SwalerLevels.INFO});

logger.info("Won't be logged");
loggerWithLevel.info('Will be logged');