edge-logger

The Next.js Edge Runtime is extremely limited as to the packages it can load.

This can pose a challenge for common logging and utility packages like winston and lodash, which will fail when loaded into an edge resource.

Logging is a cross-cutting concern, and shouldn't have to care where it is executed. So this package is a simple, flexible logging utility that...

• formats logs attractively, whether output to the console or cloud services like AWS CloudWatch.
• features configurable logging levels (defaults to SysLog).
• can handle virtually any input, including circular object references.
• can truncate long strings for readability.

Installation

npm install @karmaniverous/edge-logger

Usage

import Logger from `@karmaniverous/edge-logger`;
const logger = new Logger();

logger.emerg('emergency message', { foo: 'bar' }); // rendered with console.error()
logger.alert('alert message');                     // rendered with console.error()
logger.crit('critical message');                   // rendered with console.error()
logger.error('error message');                     // rendered with console.error()
logger.warning('warning message');                 // rendered with console.warn()
logger.notice('notice message');                   // rendered with console.info()
logger.info('info message');                       // rendered with console.info()
logger.debug('debug message');                     // rendered with console.debug()
logger.log('log message');                     // rendered with console.info()

// emerg:   emergency message
// emerg:   {
// emerg:     "foo": "bar"
// emerg:   }
// alert:   alert message
// crit:    critical message
// error:   error message
// warning: warning message
// notice:  notice message
// info:    info message
// info:    log message

// debug level not rendered by default.
// Set LOG_LEVEL to 'debug' to see these.

Configuration

Set your minimum logging level with environment variable LOG_LEVEL (by default it is info).

The optional constructor config argument has the following keys:

| Key | Description | | -------------- | ------------------------------------------------------------------------------------------------------------------------ | | defaultLevel | Default logging level (invoked by the log method). Default value set in levels object (info for default levels). | | maxLevel | Maximum logging level. Default value set in levels object (info for default levels). | | levels | An alternate levels definition. See below for details. |

Levels Config

Here is the default levels object:

{
  emerg: { value: 0, console: 'error' },
  alert: { value: 1, console: 'error' },
  crit: { value: 2, console: 'error' },
  error: { value: 3, console: 'error' },
  warning: { value: 4, console: 'warn' },
  notice: { value: 5, console: 'info' },
  info: { value: 6, console: 'info', default: true, defaultMax: true },
  debug: { value: 7, console: 'debug' },
}

Each key will be rendered as a function on the Logger instance that takes a list of items, just like console.log().

The keys on each log level:

| Key | Description | | ------------ | ----------------------------------------------------- | | value | Supports setting the logging threshold. | | console | The console function invoked by the log level. | | default | true if the log method should trigger this level. | | defaultMax | true if default max level. |

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