babel/packages/babel-plugin-check-es2015-constants/README.md

babel-plugin-check-es2015-constants

Validate ES2015 constants (prevents reassignment of const variables).

Example

In

const a = 1;
a = 2;

Out

repl: "a" is read-only
  1 | const a = 1;
> 2 | a = 2;
    | ^

Installation

npm install --save-dev babel-plugin-check-es2015-constants

Usage

Via .babelrc (Recommended)

.babelrc

{
  "plugins": ["check-es2015-constants"]
}

Via CLI

babel --plugins check-es2015-constants script.js

Via Node API

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

Note

This check will only validate consts. If you need it to compile down to var then you must also install and enable transform-es2015-block-scoping.