code incorrectly dropped

[CarloCannas]

Rollup Version

v2.50.5

Operating System (or Browser)

n/a

Node Version (if applicable)

No response

Link To Reproduction

https://rollupjs.org/repl/?version=2.50.5&shareable=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

Expected Behaviour

The statement if (typeof obj.testfn === "function"){obj.testfn()} is present in output, running the code prints yay in the console.

Actual Behaviour

Rollup drops line 4, running the output code doesn't print anything in console.

Version 2.50.5 seems to be the one which introduced the issue: on 2.50.4 line 4 isn't dropped.

Is seems to be async/await releated: removing await from the iife body produces the expected output, adding async to fn instead makes the issue appear again.

Seems a regression introduced by #4115

[lukastaegert]

Thanks for spotting, fix at #4162

[CarloCannas]

Wow, thank you for the really quick fix!

[CarloCannas]

@lukastaegert unfortunately it seems the fix doesn't work in every case: if I make fn async and put it in another module the issue comes back.

https://rollupjs.org/repl/?version=2.52.6&shareable=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

Could you please give another look at it?

[lukastaegert]

Turns out it was only the async keyword, which triggered a different, albeit related issue. Fix at #4163.