Function returned by function has default parameters incorrectly stripped

[bluwy]

Rollup Version

2.74.0

Operating System (or Browser)

macos

Node Version (if applicable)

No response

Link To Reproduction

https://rollupjs.org/repl/?version=2.74.0&shareable=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

Expected Behaviour

In the repro, the line:

return (type, detail, { cancelable = false } = {}) => {

The third parameter should be left as is.

Actual Behaviour

Rollup compiles the line to

return (type, detail, { cancelable }) => {

causing runtime errors, e.g. sveltejs/kit#4988

Note: Similar issues #4505, #4506

[lukastaegert]

Thank you so much! Considering the issues, I will roll back the parameter default tree-shaking in a patch release for now and refine it for another few days. Please keep the issue open as I intend to fix it with a proper release later.

[lukastaegert]

I created a new PR #4510 that reimplements parameter tree-shaking in a more conservative way. Could you verify that this PR works for you via npm install rollup/rollup#parameter-defaults?

[bluwy]

Looks like that fixes it! I tried the repro from sveltejs/kit#4988 with

{
  "overrides": {
    "rollup": "rollup/rollup#parameter-defaults"
  }
}

And npm run build, npm run preview, and it worked without issues. Tested locally, stackblitz doesn't support overrides