Types are generally incompatible with ReadonlyArray

[lukpsaxo]

Provide a general summary of the issue here

Props that take array's generally use the mutable form e.g. here the columns

https://github.com/adobe/react-spectrum/blob/main/packages/react-aria-components/src/Table.tsx#L529

🤔 Expected Behavior?

They instead be typed to take ReadonlyArray where the array is not mutated - that then allows the consumer to pass a mutable or a readonly array.

😯 Current Behavior

An error trying to assign a readonly array to a prop that takes a mutable array

💁 Possible Solution

Updating alot of T[] -> ReadonlyArray<T>

🔦 Context

We use readonly arrays frequently to make sure no-one is mutating a value they shouldn't and causing a unintended side effect. The current design means we would need to add a typescript expect error to use readonly arrays or a cast.

🖥️ Steps to Reproduce

N/A

Version

N/A

What browsers are you seeing the problem on?

Other

If other, please specify.

No response

What operating system are you using?

N/A

🧢 Your Company/Team

No response

🕷 Tracking Issue

No response

[lukpsaxo]

I can contribute PR's to update where and as it affects me but I'd like a response as to whether you would accept those first.

[reidbarber]

Thanks for the issue, and apologies for the delay! Brought this up with the team it looks like these should probably be Iterable<T> to match our existing collection types. Would that also fix your issue?

[lukpsaxo]

Thanks, it fixes it, I can raise a PR

[reidbarber]

That would be great!