npm install --save-dev babel-plugin-transform-es2015-block-scoped-functions
.babelrc（推荐）.babelrc
{
"plugins": ["transform-es2015-block-scoped-functions"]
}
babel --plugins transform-es2015-block-scoped-functions script.js
require("babel-core").transform("code", {
plugins: ["transform-es2015-block-scoped-functions"]
});