Binding `export const` props broke with Svelte 3.54

[GauBen]

Describe the bug

I use export const to expose component methods and Svelte's behavior changed with the 3.54 release (probably because of Prevent running init binding unnecessarily).

It looks roughly like this:

Parent.svelte:

<script>
  let closeModal = () => {}
</script>

<Modal bind:closeModal />

<!-- Since Svelte 3.54, clicking this button does nothing -->
<button on:click={closeModal}>close</button>

Modal.svelte

<script>
  export const closeModal = () => { /* ... */ }
</script>

It used to work with Svelte <= 3.53.1.

I'm not sure if this is the best way to implement this kind of behavior, any advice would be welcome.

---

Related: #8168
Suspected breaking change: (edited) #7981

Reproduction

• Always works: https://svelte.dev/repl/2ca58f269fa3486d83abc9cea27ad27c?version=3.53.1
• Does not work with a default value: https://svelte.dev/repl/2ca58f269fa3486d83abc9cea27ad27c?version=3.54.0

Logs

No response

System Info

-

Severity

annoyance

[dummdidumm]

Duplicate of #8103, fixed through #8114, release pending

[GauBen]

Thanks for the quick answer!