babel/packages/babel-plugin-transform-duplicate-keys/README.md

@babel/plugin-transform-duplicate-keys

Compile objects with duplicate keys to valid strict ES5.

This plugin actually converts duplicate keys in objects to be computed properties, which then must be handled by the @babel/plugin-transform-computed-properties plugin. The final result won't contain any object literals with duplicate keys.

Example

In

var x = { a: 5, a: 6 };
var y = {
  get a() {},
  set a(x) {},
  a: 3
};

Out

var x = { a: 5, ["a"]: 6 };
var y = {
  get a() {},
  set a(x) {},
  ["a"]: 3
};

Installation

npm install --save-dev @babel/plugin-transform-duplicate-keys

Usage

Via .babelrc (Recommended)

.babelrc

{
  "plugins": ["@babel/plugin-transform-duplicate-keys"]
}

Via CLI

babel --plugins @babel/plugin-transform-duplicate-keys script.js

Via Node API

require("@babel/core").transform("code", {
  plugins: ["@babel/plugin-transform-duplicate-keys"]
});