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Logger API ​

Vercube provides a flexible and extensible logging system through the @vercube/logger package. This documentation covers the complete API of the logger package.

Install ​

The easiest way to get started with Vercube Logger is to use install package:

bash
$ pnpm add @vercube/logger
bash
$ npm i @vercube/logger
bash
$ yarn add @vercube/logger
bash
$ bun add @vercube/logger

Overview ​

The logging system in Vercube consists of several key components:

  1. Logger: The main interface for logging messages at different levels
  2. LoggerProvider: Abstract base class for implementing log providers
  3. BaseLogger: Default implementation of the Logger interface
  4. Built-in Providers: Console and JSON providers for outputting logs

Table of Contents ​

  • Logger - The main Logger interface and BaseLogger implementation
  • Providers - Available log providers and how to create custom ones
  • Types - Type definitions used in the logging system
  • Advanced Topics - Advanced usage patterns and techniques

Quick Start ​

typescript
export function useContainer(container: Container): Container {

  // Bind the logger to the container
  container.bind(Logger, BaseLogger);

  // Configure the logger
  container.get(Logger).configure({
    logLevel: 'info',
    providers: [
      {
        name: 'console',
        provider: ConsoleProvider,
        logLevel: 'debug'
      }
    ]
  });
}
typescript
export class ExampleService {

  @Inject(Logger)
  private logger: Logger;

  public someMethod(): void {
    this.logger.info('Application started');
    this.logger.debug('Debug information', { userId: 123 });
    this.logger.warn('Warning message', new Error('Something went wrong'));
    this.logger.error('Error occurred', new Error('Critical error'));
  }

}

Core Concepts ​

Logger ​

The Logger is the main interface for logging messages. It provides methods for logging at different levels:

  • debug(): For detailed debugging information
  • info(): For general operational information
  • warn(): For warning messages
  • error(): For error messages

LoggerProvider ​

LoggerProvider is an abstract base class for implementing log providers. Providers are responsible for processing and outputting log messages to various destinations.

Log Levels ​

Vercube's logger supports four log levels:

  • debug: Detailed information for debugging
  • info: General information about application operation
  • warn: Warning messages for potentially harmful situations
  • error: Error messages for serious issues

Log levels are hierarchical, meaning that if you set the log level to warn, only warn and error messages will be processed.

Best Practices ​

  1. Use Appropriate Log Levels

    • debug: For detailed information useful during development
    • info: For general operational information
    • warn: For potentially harmful situations
    • error: For errors that need attention

  2. Include Context in Log Messages

    • Add relevant data to help with debugging
    • Include request IDs for tracking requests
    • Add user IDs for user-related operations

  3. Use Structured Logging for Production

    • Use the JSONProvider in production
    • Include timestamps and log levels
    • Add correlation IDs for distributed tracing

  4. Configure Different Log Levels for Different Environments

    • More verbose in development
    • More restrictive in production

  5. Handle Sensitive Information

    • Never log passwords or tokens
    • Mask sensitive data before logging
    • Be careful with user input in logs

See Also ​