fix: Make sure 'func' doesn't clash with destructured contexts (#8840)

Fixes: #8753

.changeset/eight-emus-allow.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: ensure identifiers in destructuring contexts don't clash with existing ones

packages/svelte/src/compiler/compile/nodes/shared/Context.js

@@ -36,6 +36,7 @@ export function unpack_destructuring({
 		if (in_rest_element) {
 			context_rest_properties.set(node.name, node);
 		}
+		component.used_names.add(node.name);
 	} else if (node.type === 'ArrayPattern') {
 		node.elements.forEach((element, i) => {
 			if (!element) {

packages/svelte/test/runtime/samples/await-block-func-function/_config.js

@@ -0,0 +1,25 @@
+export default {
+	get props() {
+		return {
+			thePromise: new Promise((_) => {})
+		};
+	},
+
+	html: `
+		Waiting...
+	`,
+
+	async test({ assert, component, target }) {
+		await (component.thePromise = Promise.resolve({ func: 12345 }));
+
+		assert.htmlEqual(target.innerHTML, '12345');
+
+		try {
+			await (component.thePromise = Promise.reject({ func: 67890 }));
+		} catch (e) {
+			// do nothing
+		}
+
+		assert.htmlEqual(target.innerHTML, '67890');
+	}
+};

packages/svelte/test/runtime/samples/await-block-func-function/main.svelte

@@ -0,0 +1,11 @@
+<script>
+	export let thePromise;
+</script>
+
+{#await thePromise}
+	Waiting...
+{:then { func }}
+	{(() => func)()}
+{:catch { func: func_1 }}
+	{(() => func_1)()}
+{/await}

packages/svelte/test/runtime/samples/const-tag-func-function/_config.js

@@ -0,0 +1,5 @@
+export default {
+	html: `
+		[12,13,14]
+	`
+};

packages/svelte/test/runtime/samples/const-tag-func-function/main.svelte

@@ -0,0 +1,8 @@
+<script>
+	const func = 100;
+</script>
+
+{#if true}
+	{@const [func_1] = [[12, 13, 14]]}
+	{(() => JSON.stringify(func_1))()}
+{/if}

packages/svelte/test/runtime/samples/each-block-func-function/_config.js

@@ -0,0 +1,9 @@
+export default {
+	html: `
+		<p>1</p>
+		<p>2</p>
+		<p>3</p>
+		<p>4</p>
+		<p>5</p>
+	`
+};

packages/svelte/test/runtime/samples/each-block-func-function/main.svelte

@@ -0,0 +1,3 @@
+{#each [1, 2, 3, 4, 5] as func}
+	<p>{(() => func)()}</p>
+{/each}