args validation

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

@@ -1070,7 +1070,7 @@ export const validation_runes = merge(validation, a11y_validators, {
 		// TODO some of this is duplicated with above, seems off
 		if ((rune === '$derived' || rune === '$derived.by') && args.length !== 1) {
 			error(node, 'invalid-rune-args-length', rune, [1]);
-		} else if (rune === '$state' && args.length > 1) {
+		} else if ((rune === '$state' || rune === '$bindable') && args.length > 1) {
 			error(node, 'invalid-rune-args-length', rune, [0, 1]);
 		} else if (rune === '$props') {
 			if (state.has_props_rune) {

packages/svelte/tests/compiler-errors/samples/runes-wrong-bindable-args/_config.js

@@ -0,0 +1,8 @@
+import { test } from '../../test';
+
+export default test({
+	error: {
+		code: 'invalid-rune-args-length',
+		message: '$bindable can only be called with 0 or 1 arguments'
+	}
+});

packages/svelte/tests/compiler-errors/samples/runes-wrong-bindable-args/main.svelte

@@ -0,0 +1,3 @@
+<script>
+	const { foo = $bindable(1, 2) } = $props();
+</script>