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babel-preset-es2015 -> babel-preset-env
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我们非常 😸 高兴你正在使用 ES2015 语法，但不是继续每年度的 preset, 团队推荐使用 babel-preset-env. 默认情况下，他和之前的 preset 将 ES2015+ 编译到 ES5 具有相同的行为。 查看 v1.x readme 以获得更多信息。 (对于 Babel 7, 我们将 preset 移动到了 main babel repo) 。

Babel 7

如果你使用 v7 版本，你将需要运行 npm install @babel/preset-env 并添加 "presets": ["@babel/env"] 在你的配置中。

Before you do anything

You might end up on this page because you saw a message in the terminal like this:

🙌 Thanks for using Babel: we recommend using babel-preset-env now: please read babeljs.io/env to update!

Before you proceed further, ask yourself: are you using Babel? Check your package.json and look for babel-preset-es2015 or a similar preset there. If you see a preset like this in your package.json, read on!

If you don't use Babel or don't use deprecated yearly presets, you probably saw this message because another package you depend on uses them. In that case there's nothing you need to do. Nevertheless, it might be a good idea to find out which package uses the deprecated presets, and help them migrate by sending a pull request. You can find this out by running npm ls babel-preset-es2015 which will show the dependency tree.

升级到 babel-preset-env

安装

npm install babel-preset-env --save-dev

.babelrc 基本变化

{
+  "presets": ["env"]
-  "presets": ["es2015"]
}

.babelrc 带选项的变化

{
  "presets": [
+   ["env", {
-   ["es2015", {
      "modules": false
    }]
  ]
}

babel-preset-env 是一个新的 preset, 一年前首次发布，取代了之前用过的很多 preset, 其中包括：

  • babel-preset-es2015, babel-preset-es2016, babel-preset-es2017
  • babel-preset-latest
  • 其他社区插件涉及到 es20xx:
    • babel-preset-node5, babel-preset-es2015-node, 等等

针对特定浏览器，Babel 可以最更少的工作使你可以传输原生 ES2015+ 代码😎!

.babelrc 针对一个特定 chrome 版本

{
  "presets": [
    ["env", {
      "targets": {
        "chrome": "60"
      }
    }]
  ]
}

.babelrc 针对当前 node 版本

{
  "presets": [
    ["env", {
      "targets": {
        "node": "current"
      }
    }]
  ]
}

babel-preset-env 的一些历史

查看 readme 获得更多信息以及更详细的文档。