AdGuard Logger

AdGuard Logger is a simple tool designed for logging from AdGuard extensions.

Usage

Installation

pnpm add @adguard/logger

Basic Usage

The package supports both CommonJS and ES Module import styles.

const { Logger } = require('@adguard/logger');
// or
import { Logger } from '@adguard/logger';

const logger = new Logger();
logger.info('This is an info message');

The default log level is set to info, meaning that messages at the debug level won't be logged. You can adjust this by setting the log level:

import { Logger, LogLevel } from './Logger';

const logger = new Logger();
logger.currentLevel = LogLevel.Debug;
console.log(logger.currentLevel); // Outputs 'debug'
logger.debug('This is a debug message');

Additionally, you can customize your logging solution by providing your own log writer, rather than relying solely on the default console logger:

import { Logger, LogLevel } from './Logger';

const writeToFile = (...args: any[]) => {
// Implement file writing logic here
};
const writer = {
    log: (...args: any[]): void => {
        writeToFile(...args);
        console.log(...args);
    },
    error: (...args: any[]): void => {
        writeToFile(...args);
        console.error(...args);
    },
    info: (...args: any[]): void => {
        writeToFile(...args);
        console.info(...args);
    },
};
const logger = new Logger(writer);

Verbose logging and trace output

This mode is designed solely for development and debugging purposes, providing clickable call stack traces in the console for maximum insight into code execution.

When the logger is set to LogLevel.Verbose, every log method except error() will print with a call stack trace. This helps track the flow of execution and diagnose complex issues. The stack trace is shown as a collapsed group in the console if the writer supports groupCollapsed and groupEnd, making logs more readable; otherwise, traces are printed expanded.

To enable this behavior, the following conditions must be met:

• Logging level must be set to LogLevel.Verbose.
• The log method must not be error() (since error() already includes a stack trace).

This feature is intended for developers who need detailed, step-by-step tracking of application execution.

Documentation

• Changelog
• Development guide
• LLM agent rules