Resolve test failures

tests/unit/mobile-menu-helper.test.ts

@@ -29,11 +29,17 @@ function createNavDOM() {
 
     const header = document.createElement('div');
     header.className = 'mobile-nav-header';
+    const toggleButton = document.createElement('button');
+    toggleButton.type = 'button';
+    toggleButton.id = 'nav-toggle-button';
+    toggleButton.setAttribute('aria-controls', 'nav-menu');
+    toggleButton.setAttribute('aria-expanded', 'false');
     const label = document.createElement('label');
     label.id = 'nav-toggle-label';
     label.htmlFor = 'nav-toggle';
     label.className = 'nav-toggle';
-    header.appendChild(label);
+    toggleButton.appendChild(label);
+    header.appendChild(toggleButton);
     nav.appendChild(header);
 
     const menu = document.createElement('div');
@@ -53,7 +59,7 @@ function createNavDOM() {
     nav.appendChild(menu);
 
     document.body.appendChild(nav);
-    return { nav, menu, label, checkbox, item };
+    return { nav, menu, toggleButton, label, checkbox, item, link };
 }
 
 describe('mobile-menu-helper.js', () => {
@@ -75,7 +81,12 @@ describe('mobile-menu-helper.js', () => {
 
     it('sets aria-hidden on menu when viewport is mobile and menu is closed', () => {
         expect(dom.menu.getAttribute('aria-hidden')).toBe('true');
-        expect(dom.label.getAttribute('aria-expanded')).toBe('false');
+        expect(dom.toggleButton.getAttribute('aria-expanded')).toBe('false');
+    });
+
+    it('sets inert and tabindex="-1" on links when menu is closed on mobile', () => {
+        expect(dom.menu.hasAttribute('inert')).toBe(true);
+        expect(dom.link.getAttribute('tabindex')).toBe('-1');
     });
 
     it('sets aria-hidden to false when menu is open on mobile', () => {
@@ -83,35 +94,55 @@ describe('mobile-menu-helper.js', () => {
         dom.checkbox.dispatchEvent(new Event('change', { bubbles: true }));
 
         expect(dom.menu.getAttribute('aria-hidden')).toBe('false');
-        expect(dom.label.getAttribute('aria-expanded')).toBe('true');
+        expect(dom.toggleButton.getAttribute('aria-expanded')).toBe('true');
     });
 
-    it('removes aria-hidden from menu when viewport is desktop', () => {
+    it('removes inert and link tabindex when menu is open on mobile', () => {
+        dom.checkbox.checked = true;
+        dom.checkbox.dispatchEvent(new Event('change', { bubbles: true }));
+
+        expect(dom.menu.hasAttribute('inert')).toBe(false);
+        expect(dom.link.hasAttribute('tabindex')).toBe(false);
+    });
+
+    it('removes aria-hidden and inert from menu when viewport is desktop', () => {
         setViewportWidth(1024);
         window.dispatchEvent(new Event('resize'));
 
         expect(dom.menu.hasAttribute('aria-hidden')).toBe(false);
+        expect(dom.menu.hasAttribute('inert')).toBe(false);
+        expect(dom.link.hasAttribute('tabindex')).toBe(false);
     });
 
-    it('adds aria-hidden when resizing from desktop to mobile', () => {
+    it('adds aria-hidden and inert when resizing from desktop to mobile', () => {
         setViewportWidth(1024);
         window.dispatchEvent(new Event('resize'));
         expect(dom.menu.hasAttribute('aria-hidden')).toBe(false);
+        expect(dom.menu.hasAttribute('inert')).toBe(false);
 
         setViewportWidth(400);
         window.dispatchEvent(new Event('resize'));
         expect(dom.menu.getAttribute('aria-hidden')).toBe('true');
+        expect(dom.menu.hasAttribute('inert')).toBe(true);
+        expect(dom.link.getAttribute('tabindex')).toBe('-1');
     });
 
     it('closes menu and syncs aria when a menu item is clicked', () => {
         dom.checkbox.checked = true;
         dom.checkbox.dispatchEvent(new Event('change', { bubbles: true }));
-        expect(dom.label.getAttribute('aria-expanded')).toBe('true');
+        expect(dom.toggleButton.getAttribute('aria-expanded')).toBe('true');
 
         dom.item.click();
 
         expect(dom.checkbox.checked).toBe(false);
-        expect(dom.label.getAttribute('aria-expanded')).toBe('false');
+        expect(dom.toggleButton.getAttribute('aria-expanded')).toBe('false');
         expect(dom.menu.getAttribute('aria-hidden')).toBe('true');
+        expect(dom.menu.hasAttribute('inert')).toBe(true);
+        expect(dom.link.getAttribute('tabindex')).toBe('-1');
     });
+
+    // Keyboard open (Enter/Space on toggle button) is not asserted here: jsdom’s KeyboardEvent
+    // often does not set e.key, so the keydown handler may not run. Opening and sync are covered
+    // by “sets aria-hidden to false when menu is open” and “removes inert and link tabindex when
+    // menu is open”; keyboard open can be covered in e2e.
 });