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 1 is:

Stage 1: proposal

What is it? A formal proposal for the feature.

What’s required? A so-called champion must be identified who is responsible for the proposal. Either the champion or a co-champion must be a member of TC39 (source). The problem solved by the proposal must be described in prose. The solution must be described via examples, an API and a discussion of semantics and algorithms. Lastly, potential obstacles for the proposal must be identified, such as interactions with other features and implementation challenges. Implementation-wise, polyfills and demos are needed.

What’s next? By accepting a proposal for stage 1, TC39 declares its willingness to examine, discuss and contribute to the proposal. Going forward, major changes to the proposal are expected

Install

npm install --save-dev @babel/preset-stage-1

Usage

Via .babelrc (Recommended)

.babelrc

{
  "presets": ["@babel/preset-stage-1"]
}

Via CLI

babel script.js --presets @babel/preset-stage-1

Via Node API

require("@babel/core").transform("code", {
  presets: ["@babel/preset-stage-1"]
});

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.

decoratorsLegacy

boolean, defaults to false.

Use the legacy (stage 1) decorators syntax and behavior.

References

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