💻

• Would you like to work on a fix?

How are you using Babel?

Programmatic API (babel.transform, babel.parse)

Input code

export default interface {}

REPL

Configuration file name

No response

Configuration

{
  "presets": ["@babel/preset-typescript"]
}

Current and expected behavior

Current: Parsed incorrectly as an ExportDeclaration with ObjectExpression.

Expected: Babel should throw an identifier is expected after interface, aligning to TSC behaviour: TS Playground

Environment

REPL

Possible solution

Babel parser handles export default interface {} in

The tsCheckLineTerminator eats interface but then since parser doesn't see a tt.name (identifier token) following, it exits without rewinding the parser states so the source is parsed as if it were export default {}.

We can perform lookahead after interface and see if it is a tt.name in

like how we handle export default abstract class:

Additional context

No response