This is a repro of what I think might be a bug in esbuild where it interprets an empty file as a module with a default export when it is imported via import *.

To reproduce:

• Make sure you have node 14 or newer (so you can run ESM w/out compiling anything)
• Run b.mjs with node:

$ node b.mjs

You should see the following console output:

[Module] {  }

It's an empty module (no exports).

• Next, run install + esbuild:

$ npm install
$ esbuild --bundle --outfile=out.js b.mjs

• Now, run the esbuild output:

$ node out.js

You should see the following console output:

{ default: {} }

The built module is an object with a single default export which is an empty object.