babel-plugin-transform-remove-polyfill

babel-plugin-transform-remove-polyfill

Install

npm i babel-plugin-transform-remove-polyfill -D
# or
yarn add babel-plugin-transform-remove-polyfill -D

Example

Before:

var __assign = Object.assign || function (t) {
  for (var s, i = 1, n = arguments.length; i < n; i++) {
    s = arguments[i];
    for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p)) t[p] = s[p];
  }
  return t;
}

After:

var __assign = Object.assign;

Usage

With a configuration file babel.config.json

{
  "plugins": ["babel-plugin-transform-remove-polyfill"]
}

Transform options

transform

Set to true to enable all transformers

{
  "plugins": [
    [
      "babel-plugin-transform-remove-polyfill",
      {
        "transform": true
      }
    ]
  ]
}

or customization transform features

"unsafe:Array.from"

boolean, defaults to false.

{
  "plugins": [
    [
      "babel-plugin-transform-remove-polyfill",
      {
        "transform": {
          "unsafe:Array.from": true
        }
      }
    ]
  ]
}

Example:

- Array.prototype.slice.call(arguments)
+ Array.from(arguments)

⚠️ Warning: Unsafe transformation

// Object with a length property
const arrayLike = { length: 2 }

/**
 * Return empty array with length == 2
 *
 * [empty × 2]
 *   length: 2
 */
console.log(Array.prototype.slice.call(arrayLike));

/**
 * Return array with undefined values and length == 2
 *
 * [undefined, undefined]
 *   0: undefined
 *   1: undefined
 *   length: 2
 */
console.log(Array.from(arrayLike));

"optimize:Object.assign"

boolean, defaults to false.

{
  "plugins": [
    [
      "babel-plugin-transform-remove-polyfill",
      {
        "transform": {
          "optimize:Object.assign": true
        }
      }
    ]
  ]
}

Example:

- Object.assign(Object.assign({}, e), o);
+ Object.assign({}, e, o);

License

MIT