Add {@const} test case

packages/svelte/tests/runtime-runes/samples/if-nested-template/_config.js

@@ -7,10 +7,10 @@ export default test({
 		const [div] = target.querySelectorAll('div');
 
 		flushSync(() => btn1?.click());
-		assert.htmlEqual(div.innerHTML, '123');
+		assert.htmlEqual(div.innerHTML, '123 <br> 123');
 		assert.equal(div.inert, true);
 
 		flushSync(() => btn2?.click());
-		assert.htmlEqual(div.innerHTML, '123');
+		assert.htmlEqual(div.innerHTML, '');
 	}
 });

packages/svelte/tests/runtime-runes/samples/if-nested-template/main.svelte

@@ -10,6 +10,9 @@
 {#if outer}
 	<div out:outro>
 		{#if inner}
+			{@const text = inner.toString()}
+			{text}
+			<br>
 			{inner.toString()}
 		{/if}
 	</div>