Logging

BlaC provides a built-in logging system for debugging.

Global Configuration

import { configureLogger, LogLevel } from '@blac/core';

configureLogger({
  enabled: true,
  level: LogLevel.DEBUG,
  output: (entry) => console.log(JSON.stringify(entry)),
});

Options

Option	Type	Description
enabled	boolean	Enable/disable logging
level	LogLevel	Minimum level to log
output	(entry) => void	Custom output handler

Log Levels

LogLevel.ERROR = 0  // Errors only
LogLevel.WARN  = 1  // Warnings and above
LogLevel.INFO  = 2  // Info and above
LogLevel.DEBUG = 3  // Everything

Using Individual Functions

import { debug, info, warn, error } from '@blac/core';

debug('MyComponent', 'Rendering', { props });
info('UserCubit', 'User logged in', { userId: '123' });
warn('CartCubit', 'Cart is getting large', { itemCount: 100 });
error('AuthCubit', 'Login failed', { error: 'Invalid credentials' });

Each function takes:

1. context - Where the log is from (component, cubit name)
2. message - What happened
3. data (optional) - Additional data object

Custom Logger

Create isolated logger instances:

import { createLogger, LogLevel } from '@blac/core';

const logger = createLogger({
  enabled: true,
  level: LogLevel.DEBUG,
  output: (entry) => {
    // Custom formatting
    const prefix = `[${entry.level}] ${entry.context}:`;
    console.log(prefix, entry.message, entry.data || '');
  }
});

logger.debug('Context', 'Message', { data: 'value' });
logger.info('Context', 'Message');
logger.warn('Context', 'Message');
logger.error('Context', 'Message', { error });

Log Entry Structure

interface LogEntry {
  level: 'debug' | 'info' | 'warn' | 'error';
  context: string;
  message: string;
  data?: Record<string, unknown>;
  timestamp: number;
}

Environment Variable

Set log level via environment variable:

BLAC_LOG_LEVEL=debug npm start

Common Patterns

Development-Only Logging

configureLogger({
  enabled: process.env.NODE_ENV === 'development',
  level: LogLevel.DEBUG,
});

Production Error Tracking

configureLogger({
  enabled: true,
  level: LogLevel.ERROR,
  output: (entry) => {
    // Send to error tracking service
    if (entry.level === 'error') {
      errorTracker.capture(entry);
    }
  },
});

Custom Formatting

configureLogger({
  enabled: true,
  level: LogLevel.DEBUG,
  output: (entry) => {
    const time = new Date(entry.timestamp).toISOString();
    const level = entry.level.toUpperCase().padEnd(5);
    console.log(`${time} ${level} [${entry.context}] ${entry.message}`);
    if (entry.data) {
      console.log('  Data:', entry.data);
    }
  },
});

See Also

• Plugins - Build custom logging plugins
• System Events - Log state changes