`2.0.0-beta-4` inconsistent stores read after write

[mizulu]

Describe the bug

setting store values inconsistent value reads after set

Case A

https://solid2.netlify.app/#solidjs-repl:FLW_W6XfQlaEdGeCVIIS6g
setting existing keys reflect right away

Case B

setting a new key is not reflected, even with flush
https://solid2.netlify.app/#solidjs-repl:FywjO6ucRv2tLruS8ebs0g

Case C

settign a new key is reflected with flush only when there is also an effect
https://solid2.netlify.app/#solidjs-repl:sPS0n-syQ-yTS_cLUBOhGQ

Your Example Website or App

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Steps to Reproduce the Bug or Issue

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Expected behavior

consistency

Screenshots or Videos

No response

Platform

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Additional context

No response

[mizulu]

Note:

s.push(20) 

instead of

s[3] = 20 

will have a more consistent read after write.

so the issue might be with direct key setting

also it is only with array not with an object

https://solid2.netlify.app/#solidjs-repl:o_NV07MKSXK9ito0D9aX_A

[kanashimia]

So here:

https://github.com/solidjs/signals/blob/24fb1a26862d3305f7f04f49ad625253e1102942/src/store/store.ts#L356-L364

nodes is actually an empty object, and nodes.length returns undefined.
s.push(20) seems to also set s.length, so it calls this proxy setter two times.
So if you do s.push(20) it will work and s[s.length++] = 20 will also work.

It is "fixable" by adding target[overrideKey]["length"] = index; there in if (index > len) nodes.length && setSignal(nodes.length, index);.
That not the correct way of fixing it though.
Because if (prev === value) return true; will cause early exit too.
And s[s.length] = undefined also needs to work probably.
So that check may need to be changed too, or setting the length needs to be moved above... but then I'm not sure if this is the correct way of fixing it as I don't know internals much, it seems hacky.