Support spreading null or undefined props

[tienpv222]

Describe the bug

Spreading null or undefined props gives runtime errors.

While it is not exactly the same, such situation is usually supported in places like plain object or React. It might be nice if Solid provides similar behavior.

Additional consideration: support full native spreading JS object with boolean, number, etc. ?

Your Example Website or App

N/A

Steps to Reproduce the Bug or Issue

N/A

Expected behavior

Spreading null or undefined props shouldn't throw exceptions.

Screenshots or Videos

No response

Platform

N/A

Additional context

Related discussions:

• https://discord.com/channels/722131463138705510/722349143024205824/751816143085240401
• https://discord.com/channels/722131463138705510/722349143024205824/968760047029080094

[lxsmnsyc]

Doing {...(nullable ?? {})} should work, but I find it a bit inconsistent with native behavior. However that's just my personal thought.

Now I found this weird. I've been using TS for more than 3 years and I just learned this just now (since TS wouldn't allow you do this). I'm okay with supporting this but this just kind of felt weird for me 😂

[edemaine]

Maybe you've been using TS too much. 😉 It's part of ECMAScript (also in Object.assign), and quite useful when you have optional arguments (e.g. (options) => { options = {...defaults, ...options}; ... }). Indeed, this use-case is supported in TypeScript.

In the context of Solid, suppose you have an optional prop props.divProps that can be an object of props to pass in to a child component (useful when you have more than one such child component that you want to customize). It's natural to want to write <div {...props.divProps}>, which gets ignored when props.divProps is null, just like you can currently write <div foo={foo()}> which gets ignored when foo() is null.

[tienpv222]

@ryansolid Please excuse me if I'm misunderstanding. I think 5292c2d didn't handle spreading component props.

[lxsmnsyc]

@tienpv222 the commit was made in the compiler: ryansolid/dom-expressions@a8fc08c

[ryansolid]

Yeah i missed looking at mergeProps in Solid. We can add additional checks.