.babelrcH2

"emotion" must be the first plugin in your babel config plugins list.

bash
{
  "plugins": ["@emotion"]
}

@emotion 会使用@emotion/babel-plugin

而之前的emotion 会使用[babel-plugin-emotion](https://www.npmjs.com/package/babel-plugin-emotion)

可能是根据plugin返回的name匹配的

bash
export default function (babel: *, options: *) {
  if (
    options.autoLabel !== undefined &&
    !AUTO_LABEL_VALUES.includes(options.autoLabel)
  ) {
    throw new Error(
      `The 'autoLabel' option must be undefined, or one of the following: ${AUTO_LABEL_VALUES.map(
        s => `"${s}"`
      ).join(', ')}`
    )
  }

  let t = babel.types
  return {
    name: '@emotion',
    inherits: syntaxJsx,
    visitor: ...

但是babel官方的手册是根据包名匹配的，推测是出了包名，还有其他的规则，例如@emotion 会找@emotion/babel-plugin

bash
const EXACT_RE = /^module:/;
const BABEL_PLUGIN_PREFIX_RE = /^(?!@|module:|[^/]+\/|babel-plugin-)/;
const BABEL_PRESET_PREFIX_RE = /^(?!@|module:|[^/]+\/|babel-preset-)/;
const BABEL_PLUGIN_ORG_RE = /^(@babel\/)(?!plugin-|[^/]+\/)/;
const BABEL_PRESET_ORG_RE = /^(@babel\/)(?!preset-|[^/]+\/)/;
const OTHER_PLUGIN_ORG_RE = /^(@(?!babel\/)[^/]+\/)(?![^/]*babel-plugin(?:-|\/|$)|[^/]+\/)/;
const OTHER_PRESET_ORG_RE = /^(@(?!babel\/)[^/]+\/)(?![^/]*babel-preset(?:-|\/|$)|[^/]+\/)/;
const OTHER_ORG_DEFAULT_RE = /^(@(?!babel$)[^/]+)$/;