simplelog-decorator

A simple logger built as class decorator, amplify like.

Quick Start

Usage

Due to the experimental decorators feature, there are some limitations. Starting from the preferred syntax @Logger()

In TypeScript you need to simply enable experimentalDecorators: true in your tsconfig.json, to be able to use the preferred syntax.

In JavaScript you need to use external libraries like @babel/plugin-proposal-decorators to use the preferred syntax.

Anyway since a decorator is just a function, you can use it by importing the loggerDecorator method.

Arguments of logger are:

• name: optional, default value is name of class
• options:
  • level: default to info

import Logger, {loggerDecorator} from 'simplelog-decorator'

// @Logger('YourCustomClass')
// @Logger('YourCustomClass', {level: 'warn'})
// loggerDecorator()(YourClass) 
@Logger() // name will be YourClass, level info
class YourClass {
   sample_method() {
      this.logger.verbose('hi from sample_method')
      this.logger.debug('hi from sample_method')
      this.logger.info('hi from sample_method')
      this.logger.warn('hi from sample_method')
      this.logger.error('hi from sample_method')

   }
}

Limitations

As previously said, experimental decorators are used for this package implementation and since experimental it has some bugs like unsafe typing. TypeScript compiler complains when it finds out a property used inside a class that calls a decorator cause it cannot infer it, so as a temporary workaround simply declare an interface

interface Example {logger: any}

@Logger()
class Example {
   hello() {
    this.logger.debug() // THIS IS VALID
   }
}

Contributing

This has been developed as a personal project, in order to be able to have an amplify-like logger as a package, without needing to install the whole amplify lib for just logging features.

But feel free to contribute by forking this project and opening a PR once done.