14584c218c
* Handle arrow function processing via shared API rather than default plugin. * Fix a few small PR comments. * Preserve existing spec arrow 'this' rewrites, and support spec in subclass constructors.
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
Via .babelrc (Recommended)
.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"]
});