fix: apply ownership mutation ignores to bindings (#18718)

Fixes #18715.

Copy ignore comment info to the generated assignment so it's recognized later

---------

Co-authored-by: svelte-triage-bot <team@svelte.com>
Co-authored-by: Simon Holthausen <simon.holthausen@vercel.com>

.changeset/fix-binding-ownership-ignore.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: apply ownership mutation ignores to binding assignments

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

@@ -1,7 +1,7 @@
 /** @import { CallExpression, Expression, Pattern } from 'estree' */
 /** @import { AST } from '#compiler' */
 /** @import { ComponentContext } from '../types' */
-import { dev, is_ignored } from '../../../../state.js';
+import { dev, ignore_map, is_ignored } from '../../../../state.js';
 import { is_text_attribute } from '../../../../utils/ast.js';
 import * as b from '#compiler/builders';
 import { binding_properties } from '../../../bindings.js';
@@ -40,9 +40,15 @@ export function BindDirective(node, context) {
 			validate_binding(context.state, node, expression);
 		}
 
-		const assignment = /** @type {Expression} */ (
-			context.visit(b.assignment('=', /** @type {Pattern} */ (node.expression), b.id('$$value')))
+		const raw_assignment = b.assignment(
+			'=',
+			/** @type {Pattern} */ (node.expression),
+			b.id('$$value')
 		);
+		// The assignment is generated, so inherit any ignores attached to the binding
+		ignore_map.set(raw_assignment, ignore_map.get(node) ?? []);
+
+		const assignment = /** @type {Expression} */ (context.visit(raw_assignment));
 
 		if (dev) {
 			// in dev, create named functions, so that `$inspect(...)` delivers
@@ -58,16 +64,7 @@ export function BindDirective(node, context) {
 			get = b.thunk(expression);
 
 			/** @type {Expression | undefined} */
-			set = b.unthunk(
-				b.arrow(
-					[b.id('$$value')],
-					/** @type {Expression} */ (
-						context.visit(
-							b.assignment('=', /** @type {Pattern} */ (node.expression), b.id('$$value'))
-						)
-					)
-				)
-			);
+			set = b.unthunk(b.arrow([b.id('$$value')], assignment));
 
 			if (get === set) {
 				set = undefined;

packages/svelte/tests/runtime-runes/samples/ownership-invalid-mutation-binding-ignore/Item.svelte

@@ -0,0 +1,6 @@
+<script>
+	let { item } = $props();
+</script>
+
+<!-- svelte-ignore ownership_invalid_mutation -->
+<input bind:value={item.heading} />

packages/svelte/tests/runtime-runes/samples/ownership-invalid-mutation-binding-ignore/_config.js

@@ -0,0 +1,22 @@
+import { flushSync } from 'svelte';
+import { ok, test } from '../../test';
+
+export default test({
+	mode: ['client'],
+	compileOptions: {
+		dev: true
+	},
+	test({ assert, target, warnings }) {
+		const input = target.querySelector('input');
+		const output = target.querySelector('p');
+		ok(input);
+		ok(output);
+
+		input.value = 'renamed';
+		input.dispatchEvent(new Event('input', { bubbles: true }));
+		flushSync();
+
+		assert.equal(output.textContent, 'renamed');
+		assert.deepEqual(warnings, []);
+	}
+});

packages/svelte/tests/runtime-runes/samples/ownership-invalid-mutation-binding-ignore/main.svelte

@@ -0,0 +1,8 @@
+<script>
+	import Item from './Item.svelte';
+
+	let item = $state({ heading: 'initial' });
+</script>
+
+<Item {item} />
+<p>{item.heading}</p>