Question

从 Babel v7 开始，所有针对处于标准提案阶段的功能所编写的预设（stage preset）都已被弃用。 请查看 此篇博客文章 了解更多信息。

有关升级说明，请参与 这份 README。

The gist of Stage 3 is:

Stage 3: candidate

What is it? The proposal is mostly finished and now needs feedback from implementations and users to progress further.

What’s required? The spec text must be complete. Designated reviewers (appointed by TC39, not by the champion) and the ECMAScript spec editor must sign off on the spec text. There must be at least two spec-compliant implementations (which don’t have to be enabled by default).

What’s next? Henceforth, changes should only be made in response to critical issues raised by the implementations and their use.

Install

npm install --save-dev @babel/preset-stage-3

Usage

Via .babelrc (Recommended)

.babelrc

{
  "presets": ["@babel/preset-stage-3"]
}

Via CLI

babel script.js --presets @babel/preset-stage-3

Via Node API

require("@babel/core").transform("code", {
  presets: ["@babel/preset-stage-3"]
});

Options

loose

boolean, defaults to false.

Enable "loose" transformations for any plugins in this preset that allow them.

useBuiltIns

boolean, defaults to false.

Will use the native built-in instead of trying to polyfill behavior for any plugins that require one.

References

• Chapter "The TC39 process for ECMAScript features" in "Exploring ES2016 and ES2017" by Axel Rauschmayer