swiftlet-log

Logging utility with different log levels with timestamp options.

Usage

1. Installation

   Install the Logger package using npm:

   npm install swiftlet-log

   Install the Logger package using yarn:

   yarn add swiftlet-log

   Install the Logger package using pnpm:

   pnpm add swiftlet-log

2. Import and Create Logger Instance

   Import the Logger class and create an instance:

   import { Logger, LogLevel } from 'swiftlet-log'
   
   const logger = new Logger({ level: LogLevel.DEBUG, timestamp: true })

3. Log Messages

   Use the different log level methods to log messages:

   logger.debug('This is a debug message.')
   logger.info('This is an info message.')
   logger.warning('This is a warning message.')
   logger.error('This is an error message.')
   logger.trace('This is a trace message.')
   logger.fatal('This is a fatal message.')

4. Middleware

   import { Logger, LogLevel, LogMiddleware } from 'swiftlet-log'
   
   const logger = new Logger({ level: LogLevel.DEBUG, timestamp: true })
   
   const customPrefixMiddleware: LogMiddleware = (ctx, next) => {
     ctx.message = `[CUSTOM PREFIX] ${ctx.message}`
     next(ctx.message, ctx.level)
   }
   
   logger.use(customPrefixMiddleware)
   
   logger.info('This is an info message.') // 输出: [CUSTOM PREFIX] [INFO]: This is an info message.

5. Customization

• Adjust log level:

  logger.setLogLevel(LogLevel.INFO)

• Enable or disable timestamp:

  logger.enableTimestamp()
  logger.disableTimestamp()

• Add or remove log listeners:

  const customListener: LogListener = (level, message) => {
    // Your custom log listener logic
  }
  
  logger.addLogListener(customListener)
  logger.removeLogListener(customListener)

Log Levels

• DEBUG: Detailed debugging information.
• INFO: General information about system operation.
• WARNING: Indicates a potential problem.
• ERROR: Indicates a more serious problem.
• TRACE: Very detailed tracing information.
• FATAL: A very severe error that may lead to application termination.