Issue

Something goes wrong when i exporting function as default export from .vue file. It is common case when my component is functional.

How to reproduce

## if no pnpm:
# npm i -g pnpm

pnpm i
pnpm test

Expected behavior

Expect to test my functional component as any another components.

Actual behavior

I am getting a warn from Vue that my component 'is missing template or render function', and actually, by console.log, i can see, that my component in test is not a function, but it is a function in it's own module. I think that something broked in export-import mechanism.