From svelte@5.5.2 a lot of `reactive_declaration_non_reactive_property` warnings

[frederikhors]

Describe the bug

From svelte@5.5.2 I get a lot (I mean A LOT) of these warnings in browser console:

A `$:` statement (node_modules/​.pnpm/​svelte-select@5.8.3/​node_modules/​svelte-select/​Select.svelte:197:4) read reactive state that was not visible to the compiler. Updates to this state will not cause the statement to re-run. The behaviour of this code will change if you migrate it to runes mode

We are all waiting for svelte-select to upgrade but in the mean time I would like to not have all these warning in the console which also hide the warnings or real errors.

Reproduction

https://svelte.dev/playground/hello-world?version=5.5.2#H4sIAAAAAAAACm3LOwvCMBSG4b8SvqUK1e6xFNzcOxqHmp5CID0JyfFG6X-XesHF9eF9J3A3EjQO5H1Qt5B8r1bUO6F-jRKD85ShjxPkEZduAZTfax_jNl_Jy2LnLtM_t4GFWDI06myTi9IYNmLEjTEkUS15sqKGFEZVvK9NflmxM1xXv4frT1s1hlFC6C7Qki40n-Yna4ZePcsAAAA=

Severity

blocking an upgrade

[leonidaz]

I believe this should work:

// svelte.config.js

compileOptions: {
    warningFilter: (warning) =>
	!['reactive_declaration_non_reactive_property'].includes(warning.code)
}

Found an example usage in one of the tests:

svelte/packages/svelte/tests/validator/samples/ignore-warning-compiler-option/_config.js

Line 4 in c0746e0

compileOptions: {

docs are kind of skimpy at this point, definitely need more usage examples, but it's mentioned here: https://svelte.dev/docs/svelte/svelte-compiler#ModuleCompileOptions

[frederikhors]

I think they should disable warnings for node_modules files by default.

[leonidaz]

just for posterity, here's an example for disabling node_modules warning:

from sveltejs/language-tools#650 (comment)

// svelte.config.js
export default {
  compileOptions: {
    // disable all warnings coming from node_modules and all accessibility warnings
    warningFilter: (warning) => !warning.filename?.includes('node_modules') && !warning.code.startsWith('a11y')
  }
}

[jamesbirtles]

I'm not sure that warningFilter applies to runtime warnings?

[dummdidumm]

The reproduction is not a minimum reproduction, but at least it's investigateable, code for the library lives here: https://github.com/rob-balfre/svelte-select/blob/master/src/lib/Select.svelte

It's not using runes so this is definitely a bug.

[frederikhors]

The reproduction is not a minimum reproduction

What can I do to help you?

[jamesbirtles]

If it helps, i'm getting it a lot using the Flowbite tooltip which is a fair bit simpler https://github.com/themesberg/flowbite-svelte/blob/2257cbcda7ed6149ada56d6be024b6d6e9410d1c/src/lib/tooltip/Tooltip.svelte#L22-L28

https://svelte.dev/playground/bdfa59d3c27a4beabc2bfb31aa4bc4c3?version=5.5.2

[dummdidumm]

This happens because in some cases new signals are created while labeled statements are run, which itself is fine, but it messes with the detection logic. We would need to specify that certain signals (internal ones, and harmless new ones) are "fine", but I don't know how currently.

[brandonp-ais]

I'm not sure that warningFilter applies to runtime warnings?

It does not, at least in our app.

Not being able to filter out runtime warnings is making the console effectively useless for us at the moment.

[frederikhors]

The suggested fix by @leonidaz doesn't work unfortunately. After the 5.5.2 is unusable.

[LeeNPham]

Anyone else have examples for how I can remove these overzealous warnings?

[knd775]

Anyone else have examples for how I can remove these overzealous warnings?

Just wait, they'll likely be gone this week #14663