make component-exported state work

packages/svelte/src/compiler/phases/2-analyze/validation.js

@@ -966,9 +966,6 @@ export const validation_runes = merge(validation, a11y_validators, {
 		if (state.analysis.instance.scope !== state.scope) return;
 		error(node, 'invalid-legacy-export');
 	},
-	ExportSpecifier(node, { state }) {
-		validate_export(node, state.scope, node.local.name);
-	},
 	CallExpression(node, { state, path }) {
 		validate_call_expression(node, state.scope, path);
 	},

packages/svelte/src/compiler/phases/3-transform/client/utils.js

@@ -52,7 +52,10 @@ export function get_assignment_value(node, { state, visit }) {
  */
 export function is_state_source(binding, state) {
 	return (
-		(binding.kind === 'state' || binding.kind === 'frozen_state') &&
+		(binding.kind === 'state' ||
+			binding.kind === 'frozen_state' ||
+			binding.kind === 'derived' ||
+			binding.kind === 'prop') &&
 		(!state.analysis.immutable || binding.reassigned || state.analysis.accessors)
 	);
 }

packages/svelte/tests/runtime-runes/samples/exports3/_config.js

@@ -7,6 +7,6 @@ export default test({
 
 		btn?.click();
 		await Promise.resolve();
-		assert.htmlEqual(target.innerHTML, '0 1 <button>0 / 1</button>');
+		assert.htmlEqual(target.innerHTML, '1 2 <button>1 / 2</button>');
 	}
 });

packages/svelte/tests/runtime-runes/samples/exports3/main.svelte

@@ -4,4 +4,4 @@
 </script>
 
 <Sub bind:this={sub} />
-<button on:click={() => sub.increment()}>{sub?.count1.value} / {sub?.count2.value}</button>
+<button on:click={() => sub.increment()}>{sub?.count} / {sub?.doubled}</button>

packages/svelte/tests/runtime-runes/samples/exports3/sub.svelte

@@ -1,15 +1,13 @@
 <script>
-	export const count1 = $state.frozen({value: 0}); 
-	export const count2 = $state({value: 0}); 
-	
-	export function increment() { 
-		count2.value += 1;
-	}
+	let count = $state(0);
+	let doubled = $derived(count * 2);
 
-</script>
+	export { count, doubled };
 
-{count1.value}
-{count2.value} 
+	export function increment() {
+		count += 1;
+	}
+</script>
 
-<!-- so that count1/2 become sources -->
-<svelte:options accessors />
+{count}
+{doubled}