babel-plugin-transform-es2015-block-scoping

> Compile ES2015 block scoping (const and let) to ES5

Installation

``sh
npm install --save-dev babel-plugin-transform-es2015-block-scoping
`

Usage

$3

.babelrc

Without options:

`json
{
"plugins": ["transform-es2015-block-scoping"]
}
`

With options:

`json
{
"plugins": [
["transform-es2015-block-scoping", {
"throwIfClosureRequired": true
}]
]
}
`

$3

`sh
babel --plugins transform-es2015-block-scoping script.js
`

$3

`javascript
require("babel-core").transform("code", {
plugins: ["transform-es2015-block-scoping"]
});
`

Options throwIfClosureRequired

In cases such as the following it's impossible to rewrite let/const without adding an additional function and closure while transforming:

`javascript
for (let i = 0; i < 5; i++) {
setTimeout(() => console.log(i), 1);
}
`

In extremely performance-sensitive code, this can be undesirable. If "throwIfClosureRequired": true` is set, Babel throws when transforming these patterns instead of automatically adding an additional function.