@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.

---

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:

``json
{
"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.

`js
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.