Cannot 'export default' abstract, ambient class or interface

[zhuravlikjb]

export default abstract class B {

}

By the way, the same with

export default declare class B {

}

Seems to be a parser bug

[DanielRosenwasser]

In what situations would one need to make an ambient class a default export?

[mhegazy]

These two are by desing. We have felt that the export default syntax is already long enough, so no modifiers are needed. for a workaround use:

declare class  C {}
export default C;

[danquirk]

We should just allow these. It's a strange inconsistency, the workaround is more verbose, and the error gives you no help getting to the workaround.

[DanielRosenwasser]

Yeah, discussed with @danquirk and @RyanCavanaugh offline; in a .d.ts file, a default exported ambient class makes sense.

I don't think it's that unreasonable to support the original syntax.

[mhegazy]

should also cover interfaces (#3914):

export default interface User {
    wpUserID: string;
}

[RyanCavanaugh]

And namespaces: export default namespace foo { ... } (#7407)