Solid's HMR does not persist the state, but other JS frameworks can.

[Blankeos]

Describe the bug

So I don't know why I just realized this now, I thought it was normal but out of React, Svelte, Vue, and Solid.
Only Svelte and Solid don't persist state between HMR updates.

Is it because Solid and Svelte have a "compiler"?

Edit: Interestingly I found something on why Svelte disables it and how to re-enable it: https://stackoverflow.com/questions/78013735/how-do-i-preserve-state-when-hot-reloading-in-a-standard-sveltekit-dev-environme. It's good that it's at least documented, but not sure for SolidJS.

Your Example Website or App

https://github.com/blankeos/solid-hmr-signal-bugs

Steps to Reproduce the Bug or Issue

To reproduce:

1. Go to any project. cd <project>
2. bun install then bun dev then open http://localhost:3000/
3. Click on any "Counter", increase it (changes the state obviously).
4. Now make a change on the code of the project, and press save.
5. Results from testing:

• ✅ react-vite - state is persisted
• ✅ vue vite - state is persisted
• ❌ solid-start - state is NOT persisted
• ❌ solid-vike - state is NOT persisted
• ❌ solid-vite - state is NOT persisted
• ❌ svelte-vite - state is NOT persisted
• ❌ svelte-kit - state is NOT persisted

Expected behavior

State is persisted (kinda useful when styling modals currently opened, making changes the component is in a specific state, etc.)

Screenshots or Videos

solid-signal-persist-hmr.mp4

Platform

• OS: macOS
• Browser: Arc (Chrome)
• Version:
  • "solid-js": "^1.9.4"
  • "vite": "^6.0.11"

Additional context

No response

[Blankeos]

Alright I learned a bit more about this after a couple of searches. Here's a related issue: solidjs/solid-refresh#12

It's very interesting. Feel free to close this since I think it's probably too much of a hassle. I can understand Solid and Svelte are architecturally different from Vue and React.

[ryansolid]

Yeah as I think I stated in that thread it is one of the trickiest problems in the sense, it could be doable but we'd need to create a whole thing to do it. Dev Tools in general has been interesting because we don't have components, we've needed to fake them so people can visualize them. One approach we have been working on with HMR is more granular (sub module) swapping but even then you still lose the state below that point.

I think this "issue" is sufficiently kept track of elsewhere so closing.

[biowaffeln]

for people reading this in the future, I made a package that addresses this exact problem!
https://github.com/biowaffeln/solid-better-refresh