fix(): use rollup's parser

[manucorporat]

No description provided.

[calvinmetcalf]

I'm getting some failed tests when I run them locally

[schadenn]

Changing the expects like that should fix the tests - can't do it on windows though because the Snapshots seem to be having some issues with the line-endings on my machine:

const { output } = await bundle.generate({ format: 'esm' })
expect(output[0].code).toMatchSnapshot();

[paceaux]

FYI this may also resolve this particular edge-case where where the word "global", even in a comment, can cause a syntax error if the optional chain operator is used (?.) : #59