redefine-property

Better Object.defineProperty().

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Features

This is identical to Object.defineProperty() except:

• The default value of enumerable, writable and configurable is true
• If the property already exists, its descriptors are used as default, even if the property is inherited
• Invalid arguments throw with a clear error message
• Otherwise, this never throws

Example

import redefineProperty from 'redefine-property'

const object = redefineProperty({}, 'prop', { value: 0, enumerable: false })
console.log(Object.getOwnPropertyDescriptor(object, 'prop'))
// {
//   value: 0,
//   enumerable: false,
//   writable: true,
//   configurable: true,
// }

Install

npm install redefine-property

This package works in both Node.js >=18.18.0 and browsers.

This is an ES module. It must be loaded using an import or import() statement, not require(). If TypeScript is used, it must be configured to output ES modules, not CommonJS.

API

redefineProperty(value, key, descriptor)

value object
key string | symbol | number
descriptor PropertyDescriptor
Return value: value

Like Object.defineProperty(...) but with some additional features.

Usage

Default values

const object = redefineProperty({}, 'prop', { value: 0 })
console.log(Object.getOwnPropertyDescriptor(object, 'prop'))
// {
//   value: 0,
//   enumerable: true,
//   writable: true,
//   configurable: true,
// }

const otherObject = Object.defineProperty({}, 'prop', { value: 0 })
console.log(Object.getOwnPropertyDescriptor(otherObject, 'prop'))
// {
//   value: 0,
//   enumerable: false,
//   writable: false,
//   configurable: false,
// }

Keep previous descriptor

const object = redefineProperty({}, 'prop', {
  value: 0,
  enumerable: false,
  writable: true,
  configurable: true,
})
redefineProperty(object, 'prop', { value: 1, configurable: false })
console.log(Object.getOwnPropertyDescriptor(object, 'prop'))
// {
//   value: 1,
//   enumerable: false,
//   writable: true,
//   configurable: false,
// }

Keep inherited descriptor

class CustomError extends Error {}
redefineProperty(CustomError.prototype, 'name', {
  value: 'CustomError',
  enumerable: false,
})

const error = new CustomError('')
redefineProperty(error, 'name', { value: 'ExampleError' })
console.log(Object.getOwnPropertyDescriptor(error, 'name'))
// {
//   value: 'ExampleError',
//   enumerable: false,
//   writable: true,
//   configurable: true,
// }

const otherError = new CustomError('')
Object.defineProperty(otherError, 'name', { value: 'ExampleError' })
console.log(Object.getOwnPropertyDescriptor(otherError, 'name'))
// {
//   value: 'ExampleError',
//   enumerable: false,
//   writable: false,
//   configurable: false,
// }

Better validation

Object.defineProperty({}, true, { value: 0 }) // This does not throw
redefineProperty({}, true, { value: 0 }) // This throws

Exception safety

const object = new Proxy(
  {},
  {
    defineProperty: () => {
      throw new Error('example')
    },
  },
)

redefineProperty(object, 'prop', { value: 1 }) // This does not throw
Object.defineProperty(object, 'prop', { value: 1 }) // This throws

Support

For any question, don't hesitate to submit an issue on GitHub.

Everyone is welcome regardless of personal background. We enforce a Code of conduct in order to promote a positive and inclusive environment.

Contributing

This project was made with ❤️. The simplest way to give back is by starring and sharing it online.

If the documentation is unclear or has a typo, please click on the page's Edit button (pencil icon) and suggest a correction.

If you would like to help us fix a bug or add a new feature, please check our guidelines. Pull requests are welcome!