Getting Started with DoubleTie Logger

Learn how to set up and use the DoubleTie Logger in your Node.js or TypeScript project.

Getting Started Tutorial

In this tutorial, you'll set up the DoubleTie Logger and use its basic functionality. By the end, you'll understand how to create loggers, use different log levels, and format your messages.

Step 1: Create a basic logger

Create a new file in your project called logger.ts:

import { createLogger } from '@doubletie/logger';
 
// Create a logger with default settings (only logs errors)
const logger = createLogger();
 
// Export for use throughout your application
export default logger;

Step 2: Use your logger

Now you can use the logger in any file:

import logger from './logger';
 
// Log at different severity levels
logger.error('Critical failure in system', { component: 'auth', userId: '123' });
logger.warn('Resource nearly depleted', { resource: 'memory', current: '85%' });
logger.info('User login successful', { userId: '123', timestamp: new Date() });
logger.debug('Processing request', { url: '/api/users', method: 'GET' });

Step 3: Configure log levels

By default, the logger only shows error messages. Let's modify it to show all messages in development and only warnings and errors in production:

import { createLogger } from '@doubletie/logger';
 
const isDevelopment = process.env.NODE_ENV !== 'production';
 
const logger = createLogger({
  level: isDevelopment ? 'debug' : 'warn',
  appName: 'my-app'
});
 
export default logger;

You should now see all log messages in development but only warnings and errors in production.

Step 4: Using the default logger

If you prefer not to create your own logger instance, you can use the default one:

import { logger } from '@doubletie/logger';
 
logger.error('Something went wrong');
logger.info('Operation completed');

The default logger is configured to only show error messages, so you'll need to reconfigure it if you want to see other log levels:

import { logger, setLogLevel } from '@doubletie/logger';
 
// Show all log levels in development
if (process.env.NODE_ENV !== 'production') {
  setLogLevel('debug');
}
 
logger.debug('Now this debug message will appear');

Next Steps

Now that you have a basic logger set up, you can explore more advanced features: