presets fail

[TrySound]

If presets is not defined I get this error

An unexpected situation arose. Please raise an issue at https://github.com/rollup/rollup-plugin-babel/issues. Thanks!

Need more smart detection for more informative errors.

[Rich-Harris]

The error worked though – you're here 😀

I think we need to ensure that the http://babeljs.io/docs/plugins/transform-es2015-classes/ plugin is enabled for the preflight check, since that's what helps us figure out how helpers are being treated.

[TrySound]

@Rich-Harris How do this without re resolving .babelrc?

[Rich-Harris]

Think we just need to change this line to this:

var check = transform( 'export default class Foo {}', assign( {}, localOpts, {
  plugins: [ 'transform-es2015-classes' ]
}).code;

The passed-in options are merged into the nearest .babelrc, IIRC