Logsy

About

Logsy is a lightweight and zero dependency library for stylized logging in the browser console. It helps developers easily output structured and visually distinctive messages with custom styles, tags, and plugin support.

📦 Installation

yarn add @wyeg/logsy

🚀 Quick Start

import { Logsy } from '@wyeg/logsy';

Logsy.log('App init completed');

📕 Documentation

Available Log Methods

Name	Description
Logsy.log()	General-purpose logging
Logsy.info()	Informational messages
logsy.warn()	Warnings
Logsy.error()	Errors and exceptions
Logsy.spinner()	Async operation spinner

API Reference

All methods (except Logsy.spinner()) use the same API interface as console.log().

import { Logsy } from '@wyeg/logsy';

Logsy.log('Foo', { foo: 'bar' });
Logsy.info('Foo', { foo: 'bar' });
Logsy.warn('Foo', { foo: 'bar' });
Logsy.error('Foo', { foo: 'bar' }); 
// or 
Logsy.error('Foo', new Error('Error Message'));

Use Logsy.spinner() to indicate progress during asynchronous operations. The spinner message updates automatically when the promise resolves or rejects.

import { Logsy } from '@wyeg/logsy';

const fetchData = () => new Promise((resolve) => setTimeout(() => resolve({ user: 'Tom' }), 2000));
Logsy.spinner('User', fetchData());

Available options

Name	Type	Description
logsy	boolean	Required flag to identify the object as Logsy options
style	string	Custom CSS rules to style the message
label	string	LogTags

import { Logsy } from '@wyeg/logsy';

Logsy.warn('Deprecated method', { logsy: true, label: LogTags.DEPRECATED });

Logsy.warn(
  'Field "card" is deprecated',
  { logsy: true, label: LogTags.DEPRECATED },
  { card: 123, cardNumber: 123 }
);

To customize label color, use the getLabelStyle() helper:

import { Logsy, getLabelStyle } from '@wyeg/logsy';

Logsy.error('Something failed', { logsy: true, style: getLabelStyle('red') });
Logsy.log('Styled message', {
  logsy: true,
  style: 'color: lightgreen; background-color: darkgrey;',
});

Plugins

Built-in

🕵️ 1. redactSensitiveDataPlugin Automatically redacts sensitive fields from log data:

import { Logsy, redactSensitiveDataPlugin } from '@wyeg/logsy';

Logsy.use(redactSensitiveDataPlugin);

Logsy.log('User', {
  email: 'user@example.com',
  password: 'hunter2',
  token: 'abc123xyz',
  apiKey: 'secretkey123',
  profile: {
    creditCard: '4111111111111111',
    cvv: 123,
    other: 'safeValue',
  },
});

Output:

{
  email: 'user@example.com',
  password: '********',
  token: '********',
  apiKey: '********',
  profile: {
    creditCard: '********',
    cvv: '****',
    other: 'safeValue'
  }
}

Sensitive fields:

• phone
• address
• creditcardnumber
• password
• secret
• token
• apikey
• accesskey
• privatekey
• sensitive
• confidential
• creditcard
• ssn
• socialsecuritynumber
• bankaccount
• bankaccountnumber
• routingnumber
• iban
• pin
• cvv
• cvc
• otp
• onetimepassword
• securitycode
• authcode
• authtoken
• authsecret
• authkey
• jwt

🚧 2. devOnlyPlugin Prevents logging in non-development environments (NODE_ENV !== 'development'):

import { Logsy, devOnlyPlugin } from '@wyeg/logsy';

Logsy.use(devOnlyPlugin);

Logsy.log('This will only be logged in development');

Create new plugin

You can create custom plugins that transform log data or hook into the logging lifecycle.

export interface ILogsyPlugin {
    /**
     * Transform the log message and its arguments.
     * @param message The log message.
     * @param rest The rest of the arguments.
     * @returns An object containing the transformed message and arguments.
     */
    transform?: (message: string, rest: unknown[]) => {
        message: string;
        rest: unknown[];
    };

    /**
     * Called before the log message is emitted.
     * @param level The log level.
     * @param message The log message.
     * @param rest The rest of the arguments.
     */
    beforeLog?: (level: TLogLevel, message: string, rest: unknown[]) => void;

    /**
     * Called after the log message is emitted.
     * @param level The log level.
     * @param message The log message.
     * @param rest The rest of the arguments.
     */
    afterLog?: (level: TLogLevel, message: string, rest: unknown[]) => void;
}

Avaiables log levels are log, info, warn, error.

📜 License

Further details see LICENSE file.

📧 Contact

If you have any questions, suggestions, or issues, please create an issue in the GitHub repository or contact me at aspedm@gmail.com.