fix: silence a11y warning for inert elements (#16339)

* fix: silence a11y warning for inert elements

* changeset

* handle `inert=""`

* oops

---------

Co-authored-by: Rich Harris <rich.harris@vercel.com>

.changeset/tall-avocados-repair.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: silence a11y warning for inert elements

packages/svelte/src/compiler/phases/2-analyze/visitors/shared/a11y/index.js

@@ -387,7 +387,10 @@ export function check_element(node, context) {
 	switch (node.name) {
 		case 'a':
 		case 'button': {
-			const is_hidden = get_static_value(attribute_map.get('aria-hidden')) === 'true';
+			const is_hidden =
+				get_static_value(attribute_map.get('aria-hidden')) === 'true' ||
+				get_static_value(attribute_map.get('inert')) !== null;
+
 			if (!has_spread && !is_hidden && !is_labelled && !has_content(node)) {
 				w.a11y_consider_explicit_label(node);
 			}

packages/svelte/tests/validator/samples/a11y-consider-explicit-label/input.svelte

@@ -5,6 +5,7 @@
 <a href="/#" aria-label="Valid empty link"></a>
 
 <button aria-hidden='true'></button>
+<button inert></button>
 <a href="/#" aria-hidden='true'><b></b></a>
 
 <button>Click me</button>