No formatting inside #each destructuring

[janosh]

Code inside #each destructuring doesn't appear to be formatted. Using

"prettier": "^2.5.0",
"prettier-plugin-svelte": "^2.5.0",
"svelte": "^3.44.2",

Expected after formatting

<script>
  let arr = [{ a: 1 }]
</script>

{#each arr as { a, b = '' }}
  {a}
  {b}
{/each}

Actual

<script>
  let arr = [{a:1}]
</script>

{#each arr as {a,b =''}}
  {a}
  {b}
{/each}