Deno bundle regression in both 1.5.4 and 1.6.0 when a module re-exports both * and default

[nktpro]

I've managed to narrow this issue down to a bare-minimal reproducer: Given 3 files:

one.ts

export default "one";
export const one = "one";

two.ts

export * from "./one.ts";
export { default } from "./one.ts";

three.ts

import two from "./two.ts";
console.log(two);

Only deno 1.4.x would produce a valid bundle for three.ts (very verbose output but valid regardless, since we didn't have bundle tree-shaking until 1.5.x)

deno bundle ./three.ts

The bundle output of deno 1.5.4 will simply contain a single invalid statement of:

console.log(__default);

The bundle output of deno 1.6.0 is also invalid, in a slightly different way:

console.log(__default);
const __default = __default;
const __default = __default;

It's worth noting that the re-exporting pattern in two.ts is basically what skypack.dev does, so this issue would usually manifest in the wild by importing some libraries via skypack.

[kitsonk]

cc/ @kdy1

[kdy1]

The problem is that a module exports default multiple times.
I think a removing default from export * could be a solution.

[nktpro]

@kdy1 As per the example on MDN export * from ... re-exports everything except the default export. If swc exports default as well as part of export * from ... then perhaps it didn't implement ES specification correctly?

[kdy1]

@nktpro Oh, thanks! I didn't know it. Then fixing it will be much easier.
I just normalized all imports to ease handling and as a result default was exported too.