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 transform-es2015-computed-properties plugin. The final result won't contain any object literals with duplicate keys.
$ npm install babel-plugin-transform-es2015-duplicate-keys
.babelrc
{
"plugins": ["transform-es2015-duplicate-keys"]
}
$ babel --plugins transform-es2015-duplicate-keys script.js
require("babel-core").transform("code", {
plugins: ["transform-es2015-duplicate-keys"]
});