code>@babel/runtime</code is a library that contain’s Babel modular runtime helpers and a version of regenerator-runtime
.
Installation
sh
npm install --save @babel/runtime
See also:
@babel/runtime-corejs2
.
Usage
This is meant to be used as a runtime dependency
along with the Babel plugin code>@babel/plugin-transform-runtime</code. Please check out the documentation in that package for usage.
Why
Sometimes Babel may inject some code in the output that is the same and thus can be potentially re-used.
For example, with the class transform (without loose mode):
Js中文网 – 前端进阶资源教程 www.javascriptC.com ,Babel中文文档
一个致力于帮助开发者用代码改变世界为使命的平台
js
class Circle {}
turns into:
js
function _classCallCheck(instance, Constructor) {
//...
}
var Circle = function Circle() {
_classCallCheck(this, Circle);
};
this means every file that contains a class would have the _classCallCheck
function repeated each time.
With code>@babel/plugin-transform-runtime</code, it would replace the reference to the function to the code>@babel/runtime</code version.
js
var _classCallCheck = require("@babel/runtime/helpers/classCallCheck");
var Circle = function Circle() {
_classCallCheck(this, Circle);
};
code>@babel/runtime</code is just the package that contains the implementations of the functions in a modular way.
来源:Js中文网 – 前端进阶资源教程
链接:https://www.javascriptc.com/docs/babel-manual/babel-runtime