Cannot able create a Record from another Record (With all optional keys)

Apologies for missing your reply earlier.

I’m creating a JSX using the generic JSX feature of ReScript. We have a native cross-platform renderer that requires a prop in string format. However, I don’t want developers to write margins in string format like “20,20,20,20”. To address this, I’ve defined two prop types:

type margin = Margin(int, int, int, int)
type props = {key?: string, margin?: margin}

type renderProps = {key?: string, margin?: string}

Now, I need a mapper function to convert between these types. However, I encountered an issue where all keys were converting to undefined. My native renderer checks for the presence of props using hasOwnProperty and other contracts. I don’t want to change my native renderer, and I also dislike the idea of writing a JavaScript loop to remove all keys with undefined values.

I’m unable to think of any solution from the ReScript side either…