Inexact optional property types

[iwoplaza]

Environment

• unplugin: 6.2.2
• typescript: 5.7.2

Reproduction

https://stackblitz.com/edit/vitejs-vite-lovdzaug?file=unplugin-foo.ts

Describe the bug

Definitions like:

type StringFilter = FilterPattern | {
	include?: FilterPattern
	exclude?: FilterPattern
};

... can cause friction when using the TypeScript exactOptionalPropertyTypes compiler option, since under that configuration, undefined is not a valid value to be passed into include or exclude. Would it break anything to widen the type to the following?:

type StringFilter = FilterPattern | {
	include?: FilterPattern | undefined
	exclude?: FilterPattern | undefined
};

Additional information

• Would you be willing to help implement a patch for this?

[sxzz]

/cc @antfu WDYT