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  • License MIT

Compile ES2015 default and rest parameters to ES5

Package Exports

  • babel-plugin-transform-es2015-parameters

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (babel-plugin-transform-es2015-parameters) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

babel-plugin-transform-es2015-parameters

Compile ES2015 default and rest parameters to ES5

This plugin transforms ES2015 parameters to ES5, this includes:

  • Destructuring parameters
  • Default parameters
  • Rest parameters

Examples

In

function test(x = "hello", { a, b }, ...args) {
  console.log(x, a, b, args);
}

Out

function test() {
  var x = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : "hello";
  var _ref = arguments[1];
  var a = _ref.a,
      b = _ref.b;

  for (var _len = arguments.length, args = Array(_len > 2 ? _len - 2 : 0), _key = 2; _key < _len; _key++) {
    args[_key - 2] = arguments[_key];
  }

  console.log(x, a, b, args);
}

Installation

npm install --save-dev babel-plugin-transform-es2015-parameters

Caveats

Default parameters desugar into let declarations to retain proper semantics. If this is not supported in your environment then you'll need the transform-block-scoping plugin.

Usage

.babelrc

{
  "plugins": ["transform-es2015-parameters"]
}

Via CLI

babel --plugins transform-es2015-parameters script.js

Via Node API

require("babel-core").transform("code", {
  plugins: ["transform-es2015-parameters"]
});