babel-plugin-prototype-prop-define

• babel-plugin-prototype-prop-define
  • background

babel-plugin-prototype-prop-define

A babel plugin for working around javascript's "override mistake" when dealing with frozen Primordials (built-ins).

background

If your primordials are frozen, such as in SES, assigning keys that are found on the prototype will throw an error.

Object.freeze(Object.prototype)

const x = {}
x.toString = () => 'hello'
// => TypeError: Cannot assign to read only property 'toString' of object '#<Object>'

Since this is a common, this plugin is provided to transform code into a safe form using Object.defineProperty:

Object.freeze(Object.prototype)

const x = {}
Object.defineProperty(x, 'toString', {
  value: () => 'hello',
  writable: true,
  enumerable: true,
  configurable: true,
})
x.toString()
// => 'hello'