@drieam/class-default-properties

@drieam/class-default-properties

The plugin for transform properties of class which has parent class.

Table of Contents

• Why need this
• Options
• Note

• Why need this
• Options
• Note

Why need this

When we use Babel to support class properties. Let's see the follow case:

class P {
  value = 'value In P'
  constructor(obj) {
    Object.assign(this, obj)
  }
}
class S extends P {
  val = 'value in S'
}

console.log(new S({ val: 'cus' }).val) // >>> cus 

Options

• condType (default: 'typeofUndefined') 'typeofUndefined' | 'in' | 'hasOwnProperty'
  • 'typeofUndefined'
    this.val = typeof this.val !== 'undefined' ? this.val : 'value in S'
  • 'in'
    this.val = 'val' in this ? this.val : 'value in S'
  • 'hasOwnProperty'
    this.val = this.hasOwnProperty('val') ? this.val : 'value in S'

Note

{
  "plugins": [
    // NOTE: the order is important
    "class-properties-default-value",
    "transform-class-properties"
  ]
}

This project is an extension of (babel-plugin-class-properties-default-value)[https://github.com/imcuttle/babel-plugin-class-properties-default-value]