@babel/preset-stage-3

As of v7.0.0-beta.55, we've removed Babel's Stage presets. Please consider reading our blog post on this decision for more details. TL;DR is that it's more beneficial in the long run to explicitly add which proposals to use.

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For a more automatic migration, we have updated babel-upgrade to do this for you (you can run npx babel-upgrade).

If you want the same configuration as before:

{
  "plugins": [
    "@babel/plugin-syntax-dynamic-import",
    "@babel/plugin-syntax-import-meta",
    ["@babel/plugin-proposal-class-properties", { "loose": false }],
    "@babel/plugin-proposal-json-strings"
  ]
}

If you're using the same configuration across many separate projects, keep in mind that you can also create your own custom presets with whichever plugins and presets you're looking to use.

module.exports = function() {
  return {
    plugins: [
      require("@babel/plugin-syntax-dynamic-import"),
      [require("@babel/plugin-proposal-decorators"), { "legacy": true }],
      [require("@babel/plugin-proposal-class-properties"), { "loose": true }],
    ],
    presets: [
      // ...
    ],
  };
};

NOTE: Compatibility between @babel/plugin-proposal-class-properties and @babel/plugin-proposal-decorators If you are including your plugins manually and using @babel/plugin-proposal-class-properties, make sure that @babel/plugin-proposal-decorators comes before @babel/plugin-proposal-class-properties.

When using the legacy: true option of @babel/plugin-proposal-decorators, @babel/plugin-proposal-class-properties must be used in loose: true mode.

If you are not using @babel/plugin-proposal-decorators, loose mode is not needed.