@mcp-abap-adt/logger

Logger interface and implementations for MCP ABAP ADT packages.

Installation

npm install @mcp-abap-adt/logger

For structured logging with Pino (optional):

npm install pino pino-pretty

Usage

DefaultLogger (Synchronous)

DefaultLogger provides synchronous logging with icons and level prefixes, ideal for tests and CLI tools:

import { defaultLogger, DefaultLogger, LogLevel } from '@mcp-abap-adt/logger';

// Use default logger singleton
defaultLogger.info('Hello, world!');
defaultLogger.debug('Debug message');
defaultLogger.error('Error message');
defaultLogger.warn('Warning message');

// Create custom logger instance with specific log level
const logger = new DefaultLogger(LogLevel.DEBUG);
logger.info('Test info');  // Output: [INFO] ℹ️ Test info
logger.debug('Test debug'); // Output: [DEBUG] 🐛 Test debug

PinoLogger (Asynchronous)

PinoLogger provides structured logging using Pino, ideal for server applications:

import { PinoLogger, LogLevel } from '@mcp-abap-adt/logger';

// Create Pino logger (falls back to DefaultLogger if pino is not installed)
const logger = new PinoLogger(LogLevel.DEBUG);
logger.info('Server started');  // Output: ℹ️ Server started (with pino-pretty formatting)
logger.debug('Debug info');
logger.error('Error occurred');
logger.warn('Warning message');

Note: PinoLogger uses async transport, so logs may appear after test completion in Jest. This is expected behavior for server use.

Log Levels

Log levels are defined in @mcp-abap-adt/interfaces and controlled by AUTH_LOG_LEVEL environment variable:

import { LogLevel } from '@mcp-abap-adt/interfaces';

// LogLevel enum values:
// LogLevel.ERROR = 0
// LogLevel.WARN = 1
// LogLevel.INFO = 2
// LogLevel.DEBUG = 3

Environment variable values:

• error - only errors
• warn - errors and warnings
• info - errors, warnings, and info (default)
• debug - all messages

export AUTH_LOG_LEVEL=debug

For backward compatibility, DEBUG_AUTH_LOG=true also sets level to debug.

Logger Interface

All logger implementations implement the ILogger interface from @mcp-abap-adt/interfaces:

import type { ILogger } from '@mcp-abap-adt/interfaces';

interface ILogger {
  info(message: string, meta?: any): void;
  debug(message: string, meta?: any): void;
  error(message: string, meta?: any): void;
  warn(message: string, meta?: any): void;
}

// Create custom logger
class MyCustomLogger implements ILogger {
  info(message: string, meta?: any): void {
    // Custom implementation
  }
  debug(message: string, meta?: any): void {
    // Custom implementation
  }
  error(message: string, meta?: any): void {
    // Custom implementation
  }
  warn(message: string, meta?: any): void {
    // Custom implementation
  }
}

Output Format

DefaultLogger output format:

• [INFO] ℹ️ message
• [DEBUG] 🐛 message
• [ERROR] 💥 message
• [WARN] ⚠️ message

PinoLogger output format (with pino-pretty):

• Structured JSON in production
• Pretty formatted with colors and icons in development (NODE_ENV !== 'production')

License

MIT