Parser `decorators` plugin option `decoratorsBeforeExport` no longer defaulting

Bug Report

Current Behavior In a recent v7 release (maybe even the final?), the parser decorators plugin option decoratorsBeforeExport no longer defaults as it used to.

const { parse } = require('@babel/core')

const result = parse(code, {
  parserOpts: {
    plugins: [
      'decorators'
    ]
  }
})

Results in an error:

/Users/jaydenseric/Sites/demo/node_modules/@babel/core/lib/transformation/normalize-file.js:209
    throw err;
    ^

Error: The 'decorators' plugin requires a 'decoratorsBeforeExport' option, whose value must be a boolean.

This is unexpected, as the decoratorsBeforeExport option is meant to default to false. Manually providing the same value as the supposed default works:

  const result = parse(code, {
    parserOpts: {
      plugins: [
-       'decorators'
+       ['decorators', { decoratorsBeforeExport: false }]
      ]
    }
  })

Expected behavior/code A clear and concise description of what you expected to happen (or code).

Babel Configuration (.babelrc, package.json, cli command)

N/A.

Environment

• Babel version(s): v7.0.0
• Node/npm version: Node.js v10.9.0, npm v6.4.0
• OS: macOS
• Monorepo [e.g. yes/no/Lerna]: No
• How you are using Babel: [e.g. cli, register, loader]: API

Possible Solution

Additional context/Screenshots

[the-simian]

I’m struggling with this right now, when I set this:

      [
        require('@babel/plugin-proposal-decorators'),
        { decoratorsBeforeExport: false, legacy: true }
      ],

OR

      [
        require('@babel/plugin-proposal-decorators'),
        { decoratorsBeforeExport: true, legacy: true }
      ],

For both I get the same error 'decoratorsBeforeExport' can't be used with legacy decorators.

if I remove the legacy flag, like this:

      [
        require('@babel/plugin-proposal-decorators'),
        { decoratorsBeforeExport: false }
      ],

I get “The new decorators proposal is not supported yet. You must pass the "legacy": true option to @babel/plugin-proposal-decorators”.

if I remove the decoratorsBeforeExport entirely and just do the legacy flag,

[require('@babel/plugin-proposal-decorators'), { legacy: true }],

I am able to proceed…

However this does now cause errors with using decorators and then using export default. I’m aware the spec is ‘still in flux’ but what is the way to configure this where I can use decorators like

@something
export default class MyClass

Is this no longer able to be done?

[Aszmel]

recently was getting problem with this error and installed npm install --save-dev @babel/plugin-proposal-decorators and setup "babel": { "plugins": [ [ "@babel/plugin-proposal-decorators", { "legacy": true } ] ], "presets": [ "react-app" ] },

this run my code with some errors, but app was working, I’m a beginner, so hope this comment is relevant