TypeScript: enum member with the same name as an imported type prevents import stripping

Bug Report

Current Behavior If the name of an enum member matches that of an imported type, the corresponding import statement remains through transpilation, even if it’s never referenced.

Input Code

import Foo from 'some-module';

enum Enum {
  Foo
}

function myFunction(): Foo {}

(REPL link)

Expected behavior/code I expect not to see import Foo from 'some-module'; in the compiled output, since Foo is only ever used as a type.

Note that changing the name of the enum member, e.g. to Foo2, causes the import statement to be stripped.

Environment

• @babel/core: 7.1.2
• @babel/plugin-transform-typescript: 7.1.0

[chriskrycho]

@dfreeman I assume changing the name of the import also fixes the problem, i.e. with this?

import { Foo as Foo2 } from './foo';

enum Enum {
  Foo
}

function myFunction(): Foo2 {}

[nicolo-ribaudo]

This is a real bug. In this example the no-unused-variable rule wouldn’t warn:

import Foo from 'some-module';

enum Enum {
  Foo
}

function myFunction(): Foo { }

export default Enum.Foo;