Reactive operator is invoked when a store variable and an assignment to the bound variable are present

[mihaon]

Describe the bug

The reactive operator $: is invoked on text input when a store variable (but not local variable) and an assignment to the bound variable are present. This means that I can't just change a local variable to a store variable as part of the refactoring because that will break my code.

Reproduction

App.svelte:

<script>
	import {modal} from './store.js'
	let name = ''
	$: if ($modal.opened) {
		name = 'test'
		console.log('invoked')
	}
</script>

<input bind:value={name}>

store.js:

import {writable} from 'svelte/store'

export const modal = writable({
	opened: true,
})

REPL: https://svelte.dev/repl/624e932ca8d74649a0c8f3a0a65c2c49?version=3.49.0

Steps to reproduce

1. Type something to the <input>

Expected result

console.log('invoked') is not invoked

Actual result

console.log('invoked') is invoked on every type

But ...

But in the next two examples console.log('invoked') is not invoked.

Example 1

App.svelte:

<script>
	let opened = true
	let name = ''
	$: if (opened) {
		name = 'test'
		console.log('invoked')
	}
</script>

<input bind:value={name}>

REPL: https://svelte.dev/repl/4dc52fa5e027438c9e744fd347789d36?version=3.49.0

Example 2

App.svelte:

<script>
	import {modal} from './store.js'
	let name = ''
	$: if ($modal.opened) {
		console.log('invoked')
	}
</script>

<input bind:value={name}>

REPL: https://svelte.dev/repl/0aa66028eb924709bf4a1d402931fd3c?version=3.49.0

Logs

No response

System Info

REPL from svelte.dev

Severity

annoyance

[fkling]

I think this is essentially the same issue as #4933

[7nik]

I believe it's expected behaviour: you change name, the reactive block runs and changes name to "test".

But in example 1, the reactive block is considered static (runs once), which is wrong.

[dummdidumm]

Fixed in Svelte 5