Menu Button
A button that opens a menu of actions or options.
Demo
Basic Menu Button
Click the button or use keyboard to open the menu.
Last action: None
With Disabled Items
Disabled items are skipped during keyboard navigation.
Last action: None
Note: "Export" is disabled and will be skipped during keyboard navigation
Accessibility Features
WAI-ARIA Roles
| Role | Target Element | Description |
|---|---|---|
button | Trigger (<button>) | The trigger that opens the menu (implicit via <button> element) |
menu | Container (<ul>) | A widget offering a list of choices to the user |
menuitem | Each item (<li>) | An option in a menu |
WAI-ARIA menu role (opens in new tab)
WAI-ARIA Properties (Button)
| Attribute | Values | Required | Description |
|---|---|---|---|
aria-haspopup | "menu" | Yes | Indicates the button opens a menu |
aria-controls | ID reference | No | References the menu element |
WAI-ARIA Properties (Menu)
| Attribute | Target | Values | Required | Description |
|---|---|---|---|---|
aria-labelledby | menu | ID reference | Yes (or aria-label) | References the button that opens the menu |
aria-label | menu | String | Yes (or aria-labelledby) | Provides an accessible name for the menu |
aria-disabled | menuitem | true | No | Indicates the menu item is disabled |
* Either aria-labelledby or aria-label is required for an accessible name
WAI-ARIA States
| Attribute | Target | Values | Required | Change Trigger |
|---|---|---|---|---|
aria-expanded | button | true | false | Yes | Open/close menu |
Keyboard Support
Button (Closed Menu)
| Key | Action |
|---|---|
| Enter / Space | Open menu and focus first item |
| Down Arrow | Open menu and focus first item |
| Up Arrow | Open menu and focus last item |
Menu (Open)
| Key | Action |
|---|---|
| Down Arrow | Move focus to next item (wraps to first) |
| Up Arrow | Move focus to previous item (wraps to last) |
| Home | Move focus to first item |
| End | Move focus to last item |
| Escape | Close menu and return focus to button |
| Tab | Close menu and move focus to next focusable element |
| Enter / Space | Activate focused item and close menu |
| Type character | Type-ahead: focus item starting with typed character(s) |
Focus Management
This component uses the Roving Tabindex pattern for focus management:
- Focused menu item : tabIndex="0"
- Other menu items : tabIndex="-1"
- Arrow key navigation : Wraps from last to first and vice versa
- Disabled items : Skipped during navigation
- Menu closes : Focus returns to button
Hidden State
When closed, the menu uses both hidden and inert attributes to:
- Hide the menu from visual display
- Remove the menu from the accessibility tree
- Prevent keyboard and mouse interaction with hidden items
Source Code
import type { ButtonHTMLAttributes, KeyboardEvent, ReactElement } from 'react';
import { useCallback, useEffect, useId, useMemo, useRef, useState } from 'react';
export interface MenuItem {
id: string;
label: string;
disabled?: boolean;
}
export interface MenuButtonProps extends Omit<
ButtonHTMLAttributes<HTMLButtonElement>,
'aria-haspopup' | 'aria-expanded' | 'aria-controls' | 'type'
> {
items: MenuItem[];
label: string;
onItemSelect?: (itemId: string) => void;
defaultOpen?: boolean;
}
export function MenuButton({
items,
label,
onItemSelect,
defaultOpen = false,
className = '',
...restProps
}: MenuButtonProps): ReactElement {
const instanceId = useId();
const buttonId = `${instanceId}-button`;
const menuId = `${instanceId}-menu`;
const [isOpen, setIsOpen] = useState(defaultOpen);
const [focusedIndex, setFocusedIndex] = useState(-1);
const containerRef = useRef<HTMLDivElement>(null);
const buttonRef = useRef<HTMLButtonElement>(null);
const menuItemRefs = useRef<Map<string, HTMLLIElement>>(new Map());
const typeAheadBuffer = useRef<string>('');
const typeAheadTimeoutId = useRef<number | null>(null);
const typeAheadTimeout = 500;
// Get available (non-disabled) items
const availableItems = useMemo(() => items.filter((item) => !item.disabled), [items]);
// Map of item id to index in availableItems for O(1) lookup
const availableIndexMap = useMemo(() => {
const map = new Map<string, number>();
availableItems.forEach(({ id }, index) => map.set(id, index));
return map;
}, [availableItems]);
const closeMenu = useCallback(() => {
setIsOpen(false);
setFocusedIndex(-1);
// Clear type-ahead state to prevent stale buffer on reopen
typeAheadBuffer.current = '';
if (typeAheadTimeoutId.current !== null) {
clearTimeout(typeAheadTimeoutId.current);
typeAheadTimeoutId.current = null;
}
}, []);
const openMenu = useCallback(
(focusPosition: 'first' | 'last') => {
if (availableItems.length === 0) {
// All items disabled, open menu but keep focus on button
setIsOpen(true);
return;
}
setIsOpen(true);
const targetIndex = focusPosition === 'first' ? 0 : availableItems.length - 1;
setFocusedIndex(targetIndex);
},
[availableItems]
);
// Focus menu item when focusedIndex changes and menu is open
useEffect(() => {
if (!isOpen || focusedIndex < 0) return;
const targetItem = availableItems[focusedIndex];
if (targetItem) {
menuItemRefs.current.get(targetItem.id)?.focus();
}
}, [isOpen, focusedIndex, availableItems]);
const toggleMenu = useCallback(() => {
if (isOpen) {
closeMenu();
} else {
openMenu('first');
}
}, [isOpen, closeMenu, openMenu]);
const handleItemClick = useCallback(
(item: MenuItem) => {
if (item.disabled) return;
onItemSelect?.(item.id);
closeMenu();
buttonRef.current?.focus();
},
[onItemSelect, closeMenu]
);
const handleButtonKeyDown = useCallback(
(event: KeyboardEvent<HTMLButtonElement>) => {
switch (event.key) {
case 'Enter':
case ' ':
event.preventDefault();
openMenu('first');
break;
case 'ArrowDown':
event.preventDefault();
openMenu('first');
break;
case 'ArrowUp':
event.preventDefault();
openMenu('last');
break;
}
},
[openMenu]
);
const handleTypeAhead = useCallback(
(char: string) => {
if (availableItems.length === 0) return;
// Clear existing timeout
if (typeAheadTimeoutId.current !== null) {
clearTimeout(typeAheadTimeoutId.current);
}
// Add character to buffer
typeAheadBuffer.current += char.toLowerCase();
const buffer = typeAheadBuffer.current;
const isSameChar = buffer.length > 1 && buffer.split('').every((c) => c === buffer[0]);
// For same char repeated or single char, start from next item to cycle through matches
// For multi-char string, start from current to allow refining the search
let startIndex: number;
let searchStr: string;
if (isSameChar) {
// Same character repeated: cycle through matches
typeAheadBuffer.current = buffer[0];
searchStr = buffer[0];
startIndex = focusedIndex >= 0 ? (focusedIndex + 1) % availableItems.length : 0;
} else if (buffer.length === 1) {
// Single character: start from next item to find next match
searchStr = buffer;
startIndex = focusedIndex >= 0 ? (focusedIndex + 1) % availableItems.length : 0;
} else {
// Multi-character: refine search from current position
searchStr = buffer;
startIndex = focusedIndex >= 0 ? focusedIndex : 0;
}
// Search from start index, wrapping around
for (let i = 0; i < availableItems.length; i++) {
const index = (startIndex + i) % availableItems.length;
const option = availableItems[index];
if (option.label.toLowerCase().startsWith(searchStr)) {
setFocusedIndex(index);
break;
}
}
// Set timeout to clear buffer
typeAheadTimeoutId.current = window.setTimeout(() => {
typeAheadBuffer.current = '';
typeAheadTimeoutId.current = null;
}, typeAheadTimeout);
},
[availableItems, focusedIndex]
);
const handleMenuKeyDown = useCallback(
(event: KeyboardEvent<HTMLLIElement>, item: MenuItem) => {
// Guard: no available items to navigate
if (availableItems.length === 0) {
if (event.key === 'Escape') {
event.preventDefault();
closeMenu();
buttonRef.current?.focus();
}
return;
}
const currentIndex = availableIndexMap.get(item.id) ?? -1;
// Guard: disabled item received focus (e.g., programmatic focus)
if (currentIndex < 0) {
if (event.key === 'Escape') {
event.preventDefault();
closeMenu();
buttonRef.current?.focus();
}
return;
}
switch (event.key) {
case 'ArrowDown': {
event.preventDefault();
const nextIndex = (currentIndex + 1) % availableItems.length;
setFocusedIndex(nextIndex);
break;
}
case 'ArrowUp': {
event.preventDefault();
const prevIndex = currentIndex === 0 ? availableItems.length - 1 : currentIndex - 1;
setFocusedIndex(prevIndex);
break;
}
case 'Home': {
event.preventDefault();
setFocusedIndex(0);
break;
}
case 'End': {
event.preventDefault();
setFocusedIndex(availableItems.length - 1);
break;
}
case 'Escape': {
event.preventDefault();
closeMenu();
buttonRef.current?.focus();
break;
}
case 'Tab': {
// Let the browser handle Tab, but close the menu
closeMenu();
break;
}
case 'Enter':
case ' ': {
event.preventDefault();
if (!item.disabled) {
onItemSelect?.(item.id);
closeMenu();
buttonRef.current?.focus();
}
break;
}
default: {
// Type-ahead: single printable character
const { key, ctrlKey, metaKey, altKey } = event;
if (key.length === 1 && !ctrlKey && !metaKey && !altKey) {
event.preventDefault();
handleTypeAhead(key);
}
}
}
},
[availableIndexMap, availableItems, closeMenu, onItemSelect, handleTypeAhead]
);
// Cleanup type-ahead timeout on unmount
useEffect(() => {
return () => {
if (typeAheadTimeoutId.current !== null) {
clearTimeout(typeAheadTimeoutId.current);
}
};
}, []);
// Click outside to close
useEffect(() => {
if (!isOpen) return;
const handleClickOutside = (event: MouseEvent) => {
if (
containerRef.current &&
event.target instanceof Node &&
!containerRef.current.contains(event.target)
) {
closeMenu();
}
};
document.addEventListener('mousedown', handleClickOutside);
return () => document.removeEventListener('mousedown', handleClickOutside);
}, [isOpen, closeMenu]);
return (
<div ref={containerRef} className={`apg-menu-button ${className}`.trim()}>
<button
ref={buttonRef}
id={buttonId}
type="button"
className="apg-menu-button-trigger"
aria-haspopup="menu"
aria-expanded={isOpen}
aria-controls={menuId}
onClick={toggleMenu}
onKeyDown={handleButtonKeyDown}
{...restProps}
>
{label}
</button>
<ul
id={menuId}
role="menu"
aria-labelledby={buttonId}
className="apg-menu-button-menu"
hidden={!isOpen || undefined}
inert={!isOpen || undefined}
>
{items.map((item) => {
const availableIndex = availableIndexMap.get(item.id) ?? -1;
const isFocused = availableIndex === focusedIndex;
const tabIndex = item.disabled ? -1 : isFocused ? 0 : -1;
return (
<li
key={item.id}
ref={(el) => {
if (el) {
menuItemRefs.current.set(item.id, el);
} else {
menuItemRefs.current.delete(item.id);
}
}}
role="menuitem"
tabIndex={tabIndex}
aria-disabled={item.disabled || undefined}
className="apg-menu-button-item"
onClick={() => handleItemClick(item)}
onKeyDown={(e) => handleMenuKeyDown(e, item)}
onFocus={() => {
if (!item.disabled && availableIndex >= 0) {
setFocusedIndex(availableIndex);
}
}}
>
{item.label}
</li>
);
})}
</ul>
</div>
);
}
export default MenuButton; Usage
import { MenuButton } from './MenuButton';
const items = [
{ id: 'cut', label: 'Cut' },
{ id: 'copy', label: 'Copy' },
{ id: 'paste', label: 'Paste' },
{ id: 'delete', label: 'Delete', disabled: true },
];
// Basic usage
<MenuButton
items={items}
label="Actions"
onItemSelect={(id) => console.log('Selected:', id)}
/>
// With default open state
<MenuButton
items={items}
label="Actions"
defaultOpen
onItemSelect={(id) => console.log('Selected:', id)}
/> API
MenuButton Props
| Prop | Type | Default | Description |
|---|---|---|---|
items | MenuItem[] | required | Array of menu items |
label | string | required | Button label text |
defaultOpen | boolean | false | Whether menu is initially open |
onItemSelect | (id: string) => void | - | Callback when an item is selected |
className | string | '' | Additional CSS class for the container |
MenuItem Interface
interface MenuItem {
id: string;
label: string;
disabled?: boolean;
} Testing
Tests verify APG compliance across keyboard interaction, ARIA attributes, and accessibility requirements.
Test Categories
High Priority : APG Mouse Interaction
| Test | Description |
|---|---|
Button click | Opens menu on button click |
Toggle | Clicking button again closes menu |
Item click | Clicking menu item activates and closes menu |
Disabled item click | Clicking disabled item does nothing |
Click outside | Clicking outside menu closes it |
High Priority : APG Keyboard Interaction (Button)
| Test | Description |
|---|---|
Enter | Opens menu, focuses first enabled item |
Space | Opens menu, focuses first enabled item |
ArrowDown | Opens menu, focuses first enabled item |
ArrowUp | Opens menu, focuses last enabled item |
High Priority : APG Keyboard Interaction (Menu)
| Test | Description |
|---|---|
ArrowDown | Moves focus to next enabled item (wraps) |
ArrowUp | Moves focus to previous enabled item (wraps) |
Home | Moves focus to first enabled item |
End | Moves focus to last enabled item |
Escape | Closes menu, returns focus to button |
Tab | Closes menu, moves focus out |
Enter/Space | Activates item and closes menu |
Disabled skip | Skips disabled items during navigation |
High Priority : Type-Ahead Search
| Test | Description |
|---|---|
Single character | Focuses first item starting with typed character |
Multiple characters | Typed within 500ms form prefix search string |
Wrap around | Search wraps from end to beginning |
Buffer reset | Buffer resets after 500ms of inactivity |
High Priority : APG ARIA Attributes
| Test | Description |
|---|---|
aria-haspopup | Button has aria-haspopup="menu" |
aria-expanded | Button reflects open state (true/false) |
aria-controls | Button references menu ID |
role="menu" | Menu container has menu role |
role="menuitem" | Each item has menuitem role |
aria-labelledby | Menu references button for accessible name |
aria-disabled | Disabled items have aria-disabled="true" |
High Priority : Focus Management (Roving Tabindex)
| Test | Description |
|---|---|
tabIndex=0 | Focused item has tabIndex=0 |
tabIndex=-1 | Non-focused items have tabIndex=-1 |
Initial focus | First enabled item receives focus when menu opens |
Focus return | Focus returns to button when menu closes |
Medium Priority : Accessibility
| Test | Description |
|---|---|
axe violations | No WCAG 2.1 AA violations (via jest-axe) |
Example Test Code
The following is the actual E2E test file (e2e/menu-button.spec.ts).
import { test, expect } from '@playwright/test';
import AxeBuilder from '@axe-core/playwright';
/**
* E2E Tests for Menu Button Pattern
*
* A button that opens a menu containing menu items. The button has
* aria-haspopup="menu" and controls a dropdown menu.
*
* APG Reference: https://www.w3.org/WAI/ARIA/apg/patterns/menu-button/
*/
const frameworks = ['react', 'vue', 'svelte', 'astro'] as const;
// ============================================
// Helper Functions
// ============================================
const getMenuButton = (page: import('@playwright/test').Page) => {
return page.getByRole('button', { name: /actions|file/i }).first();
};
const getMenu = (page: import('@playwright/test').Page) => {
return page.getByRole('menu');
};
const getMenuItems = (page: import('@playwright/test').Page) => {
return page.getByRole('menuitem');
};
const openMenu = async (page: import('@playwright/test').Page) => {
const button = getMenuButton(page);
await button.click();
await getMenu(page).waitFor({ state: 'visible' });
return button;
};
// Wait for hydration to complete
// This is necessary for frameworks like Svelte where event handlers are attached after hydration
const waitForHydration = async (page: import('@playwright/test').Page) => {
const button = getMenuButton(page);
// Wait for aria-controls to be set (basic check)
await expect(button).toHaveAttribute('aria-controls', /.+/);
// Poll until a click actually opens the menu (ensures handlers are attached)
await expect
.poll(async () => {
await button.click();
const isOpen = await getMenu(page).isVisible();
if (isOpen) {
await page.keyboard.press('Escape');
}
return isOpen;
})
.toBe(true);
};
// ============================================
// Framework-specific Tests
// ============================================
for (const framework of frameworks) {
test.describe(`Menu Button (${framework})`, () => {
test.beforeEach(async ({ page }) => {
await page.goto(`patterns/menu-button/${framework}/demo/`);
await getMenuButton(page).waitFor();
// Wait for hydration in frameworks that need it (Svelte)
// This ensures event handlers are attached before tests run
if (framework === 'svelte') {
await waitForHydration(page);
}
});
// ------------------------------------------
// 🔴 High Priority: APG ARIA Structure
// ------------------------------------------
test.describe('APG: ARIA Structure', () => {
test('button has aria-haspopup="menu"', async ({ page }) => {
const button = getMenuButton(page);
await expect(button).toHaveAttribute('aria-haspopup', 'menu');
});
test('button has aria-expanded (false when closed)', async ({ page }) => {
const button = getMenuButton(page);
await expect(button).toHaveAttribute('aria-expanded', 'false');
});
test('button has aria-expanded (true when open)', async ({ page }) => {
const button = await openMenu(page);
await expect(button).toHaveAttribute('aria-expanded', 'true');
});
test('button has aria-controls referencing menu id', async ({ page }) => {
const button = getMenuButton(page);
// Wait for hydration - aria-controls may not be set immediately in Svelte
await expect
.poll(async () => {
const id = await button.getAttribute('aria-controls');
return id && id.length > 1 && !id.startsWith('-');
})
.toBe(true);
const menuId = await button.getAttribute('aria-controls');
expect(menuId).toBeTruthy();
await openMenu(page);
const menu = getMenu(page);
await expect(menu).toHaveAttribute('id', menuId!);
});
test('menu has role="menu"', async ({ page }) => {
await openMenu(page);
const menu = getMenu(page);
await expect(menu).toBeVisible();
await expect(menu).toHaveRole('menu');
});
test('menu has accessible name via aria-labelledby', async ({ page }) => {
await openMenu(page);
const menu = getMenu(page);
const labelledby = await menu.getAttribute('aria-labelledby');
expect(labelledby).toBeTruthy();
// Verify it references the button
const button = getMenuButton(page);
const buttonId = await button.getAttribute('id');
expect(labelledby).toBe(buttonId);
});
test('menu items have role="menuitem"', async ({ page }) => {
await openMenu(page);
const items = getMenuItems(page);
const count = await items.count();
expect(count).toBeGreaterThan(0);
for (let i = 0; i < count; i++) {
await expect(items.nth(i)).toHaveRole('menuitem');
}
});
test('disabled items have aria-disabled="true"', async ({ page }) => {
// Use the File menu demo which must have disabled item (Export)
const fileButton = page.getByRole('button', { name: /file/i });
await expect(fileButton).toBeVisible();
await fileButton.click();
await getMenu(page).waitFor({ state: 'visible' });
const disabledItem = page.getByRole('menuitem', { name: /export/i });
await expect(disabledItem).toBeVisible();
await expect(disabledItem).toHaveAttribute('aria-disabled', 'true');
});
});
// ------------------------------------------
// 🔴 High Priority: Keyboard Interaction (Button)
// ------------------------------------------
test.describe('APG: Keyboard Interaction (Button)', () => {
test('Enter opens menu and focuses first item', async ({ page }) => {
const button = getMenuButton(page);
await button.focus();
await page.keyboard.press('Enter');
await expect(getMenu(page)).toBeVisible();
await expect(button).toHaveAttribute('aria-expanded', 'true');
// First item should be focused
const firstItem = getMenuItems(page).first();
await expect(firstItem).toBeFocused();
});
test('Space opens menu and focuses first item', async ({ page }) => {
const button = getMenuButton(page);
await button.focus();
await page.keyboard.press('Space');
await expect(getMenu(page)).toBeVisible();
const firstItem = getMenuItems(page).first();
await expect(firstItem).toBeFocused();
});
test('ArrowDown opens menu and focuses first item', async ({ page }) => {
const button = getMenuButton(page);
await button.focus();
await page.keyboard.press('ArrowDown');
await expect(getMenu(page)).toBeVisible();
const firstItem = getMenuItems(page).first();
await expect(firstItem).toBeFocused();
});
test('ArrowUp opens menu and focuses last enabled item', async ({ page }) => {
const button = getMenuButton(page);
await button.focus();
await page.keyboard.press('ArrowUp');
await expect(getMenu(page)).toBeVisible();
// Find the last enabled item by checking focus
const focusedItem = page.locator(':focus');
await expect(focusedItem).toHaveRole('menuitem');
});
});
// ------------------------------------------
// 🔴 High Priority: Keyboard Interaction (Menu)
// ------------------------------------------
test.describe('APG: Keyboard Interaction (Menu)', () => {
test('ArrowDown moves to next item', async ({ page }) => {
await openMenu(page);
const items = getMenuItems(page);
const firstItem = items.first();
await firstItem.focus();
await page.keyboard.press('ArrowDown');
const secondItem = items.nth(1);
await expect(secondItem).toBeFocused();
});
test('ArrowDown wraps from last to first', async ({ page }) => {
await openMenu(page);
// Focus the last enabled item
// For basic menu, just navigate to end
for (let i = 0; i < 10; i++) {
await page.keyboard.press('End');
}
const focusedBefore = await page.evaluate(() => document.activeElement?.textContent);
await page.keyboard.press('ArrowDown');
const focusedAfter = await page.evaluate(() => document.activeElement?.textContent);
// Should have wrapped to a different item (first)
expect(focusedAfter).not.toBe(focusedBefore);
});
test('ArrowUp moves to previous item', async ({ page }) => {
await openMenu(page);
const items = getMenuItems(page);
// Start from second item
await items.nth(1).focus();
await page.keyboard.press('ArrowUp');
const firstItem = items.first();
await expect(firstItem).toBeFocused();
});
test('ArrowUp wraps from first to last', async ({ page }) => {
await openMenu(page);
const items = getMenuItems(page);
const firstItem = items.first();
await firstItem.focus();
const focusedBefore = await page.evaluate(() => document.activeElement?.textContent);
await page.keyboard.press('ArrowUp');
const focusedAfter = await page.evaluate(() => document.activeElement?.textContent);
// Should have wrapped to last item
expect(focusedAfter).not.toBe(focusedBefore);
});
test('Home moves to first enabled item', async ({ page }) => {
await openMenu(page);
const items = getMenuItems(page);
// Start from second item
await items.nth(1).focus();
await page.keyboard.press('Home');
const firstItem = items.first();
await expect(firstItem).toBeFocused();
});
test('End moves to last enabled item', async ({ page }) => {
await openMenu(page);
const items = getMenuItems(page);
const firstItem = items.first();
await firstItem.focus();
await page.keyboard.press('End');
// Focus should be on last item (or last enabled item)
const focusedItem = page.locator(':focus');
await expect(focusedItem).toHaveRole('menuitem');
// Should not be the first item anymore
const focusedText = await focusedItem.textContent();
const firstText = await firstItem.textContent();
expect(focusedText).not.toBe(firstText);
});
test('Escape closes menu and returns focus to button', async ({ page }) => {
const button = await openMenu(page);
await page.keyboard.press('Escape');
await expect(getMenu(page)).not.toBeVisible();
await expect(button).toHaveAttribute('aria-expanded', 'false');
await expect(button).toBeFocused();
});
test('Enter activates item and closes menu', async ({ page }) => {
const button = await openMenu(page);
const items = getMenuItems(page);
const firstItem = items.first();
await firstItem.focus();
await page.keyboard.press('Enter');
await expect(getMenu(page)).not.toBeVisible();
await expect(button).toBeFocused();
});
test('Space activates item and closes menu', async ({ page }) => {
const button = await openMenu(page);
const items = getMenuItems(page);
const firstItem = items.first();
await firstItem.focus();
await page.keyboard.press('Space');
await expect(getMenu(page)).not.toBeVisible();
await expect(button).toBeFocused();
});
test('Tab closes menu', async ({ page }) => {
await openMenu(page);
await page.keyboard.press('Tab');
await expect(getMenu(page)).not.toBeVisible();
});
});
// ------------------------------------------
// 🔴 High Priority: Focus Management (Roving Tabindex)
// ------------------------------------------
test.describe('APG: Focus Management', () => {
test('focused item has tabindex="0"', async ({ page }) => {
await openMenu(page);
const items = getMenuItems(page);
const firstItem = items.first();
await firstItem.focus();
await expect(firstItem).toHaveAttribute('tabindex', '0');
});
test('non-focused items have tabindex="-1"', async ({ page }) => {
await openMenu(page);
const items = getMenuItems(page);
const count = await items.count();
if (count > 1) {
const firstItem = items.first();
await firstItem.focus();
// Check second item has tabindex="-1"
const secondItem = items.nth(1);
await expect(secondItem).toHaveAttribute('tabindex', '-1');
}
});
test('disabled items are skipped during navigation', async ({ page }) => {
// Use the File menu demo which must have disabled items
const fileButton = page.getByRole('button', { name: /file/i });
await expect(fileButton).toBeVisible();
await fileButton.click();
await getMenu(page).waitFor({ state: 'visible' });
// Navigate through all items
const focusedTexts: string[] = [];
for (let i = 0; i < 10; i++) {
const text = await page.evaluate(() => document.activeElement?.textContent || '');
if (text && !focusedTexts.includes(text)) {
focusedTexts.push(text);
}
await page.keyboard.press('ArrowDown');
}
// "Export" (disabled) should not be in the focused list
expect(focusedTexts).not.toContain('Export');
});
});
// ------------------------------------------
// 🔴 High Priority: Click Interaction
// ------------------------------------------
test.describe('APG: Click Interaction', () => {
test('click button opens menu', async ({ page }) => {
const button = getMenuButton(page);
await button.click();
await expect(getMenu(page)).toBeVisible();
await expect(button).toHaveAttribute('aria-expanded', 'true');
});
test('click button again closes menu (toggle)', async ({ page }) => {
const button = getMenuButton(page);
await button.click();
await expect(getMenu(page)).toBeVisible();
await button.click();
await expect(getMenu(page)).not.toBeVisible();
await expect(button).toHaveAttribute('aria-expanded', 'false');
});
test('click menu item activates and closes menu', async ({ page }) => {
await openMenu(page);
const items = getMenuItems(page);
const firstItem = items.first();
await firstItem.click();
await expect(getMenu(page)).not.toBeVisible();
});
test('click outside menu closes it', async ({ page }) => {
await openMenu(page);
const menu = getMenu(page);
const menuBox = await menu.boundingBox();
expect(menuBox).not.toBeNull();
const viewportSize = page.viewportSize();
expect(viewportSize).not.toBeNull();
// Find a safe position outside menu, handling edge cases
const candidates = [
// Above menu (if there's space)
{ x: menuBox!.x + menuBox!.width / 2, y: Math.max(1, menuBox!.y - 20) },
// Left of menu (if there's space)
{ x: Math.max(1, menuBox!.x - 20), y: menuBox!.y + menuBox!.height / 2 },
// Right of menu (if there's space)
{
x: Math.min(viewportSize!.width - 1, menuBox!.x + menuBox!.width + 20),
y: menuBox!.y + menuBox!.height / 2,
},
// Below menu (if there's space)
{
x: menuBox!.x + menuBox!.width / 2,
y: Math.min(viewportSize!.height - 1, menuBox!.y + menuBox!.height + 20),
},
];
// Find first candidate that's outside menu bounds
const isOutsideMenu = (x: number, y: number) =>
x < menuBox!.x ||
x > menuBox!.x + menuBox!.width ||
y < menuBox!.y ||
y > menuBox!.y + menuBox!.height;
const safePosition = candidates.find((pos) => isOutsideMenu(pos.x, pos.y));
if (safePosition) {
await page.mouse.click(safePosition.x, safePosition.y);
} else {
// Fallback: click at viewport corner (1,1)
await page.mouse.click(1, 1);
}
await expect(getMenu(page)).not.toBeVisible();
});
});
// ------------------------------------------
// 🟡 Medium Priority: Type-Ahead
// ------------------------------------------
test.describe('Type-Ahead', () => {
test('single character focuses matching item', async ({ page }) => {
await openMenu(page);
// Wait for first item to be focused (menu opens with focus on first item)
const firstItem = getMenuItems(page).first();
await expect(firstItem).toBeFocused();
// Type 'p' to find "Paste" - use press() for single key
await page.keyboard.press('p');
// Wait for focus to move to item starting with 'p'
// Use trim() because some frameworks may include whitespace in textContent
await expect
.poll(async () => {
const text = await page.evaluate(
() => document.activeElement?.textContent?.trim().toLowerCase() || ''
);
return text.startsWith('p');
})
.toBe(true);
});
test('type-ahead wraps around', async ({ page }) => {
await openMenu(page);
// Focus last item
await page.keyboard.press('End');
const lastItem = getMenuItems(page).last();
await expect(lastItem).toBeFocused();
// Type character that matches earlier item - use press() for single key
await page.keyboard.press('c');
// Wait for focus to wrap and find item starting with 'c'
// Use trim() because some frameworks may include whitespace in textContent
await expect
.poll(async () => {
const text = await page.evaluate(
() => document.activeElement?.textContent?.trim().toLowerCase() || ''
);
return text.startsWith('c');
})
.toBe(true);
});
});
// ------------------------------------------
// 🟢 Low Priority: Accessibility
// ------------------------------------------
test.describe('Accessibility', () => {
test('has no axe-core violations (closed)', async ({ page }) => {
const results = await new AxeBuilder({ page })
.include('.apg-menu-button')
.disableRules(['color-contrast'])
.analyze();
expect(results.violations).toEqual([]);
});
test('has no axe-core violations (open)', async ({ page }) => {
await openMenu(page);
const results = await new AxeBuilder({ page })
.include('.apg-menu-button')
.disableRules(['color-contrast'])
.analyze();
expect(results.violations).toEqual([]);
});
});
});
}
// ============================================
// Cross-framework Consistency Tests
// ============================================
test.describe('Menu Button - Cross-framework Consistency', () => {
test('all frameworks have menu button with aria-haspopup="menu"', async ({ page }) => {
for (const framework of frameworks) {
await page.goto(`patterns/menu-button/${framework}/demo/`);
await getMenuButton(page).waitFor();
const button = getMenuButton(page);
await expect(button).toHaveAttribute('aria-haspopup', 'menu');
}
});
test('all frameworks open menu on click', async ({ page }) => {
for (const framework of frameworks) {
await page.goto(`patterns/menu-button/${framework}/demo/`);
await getMenuButton(page).waitFor();
const button = getMenuButton(page);
await button.click();
const menu = getMenu(page);
await expect(menu).toBeVisible();
// Close for next iteration
await page.keyboard.press('Escape');
}
});
test('all frameworks close menu on Escape', async ({ page }) => {
for (const framework of frameworks) {
await page.goto(`patterns/menu-button/${framework}/demo/`);
await getMenuButton(page).waitFor();
await openMenu(page);
await expect(getMenu(page)).toBeVisible();
await page.keyboard.press('Escape');
await expect(getMenu(page)).not.toBeVisible();
}
});
test('all frameworks have consistent keyboard navigation', async ({ page }) => {
for (const framework of frameworks) {
await page.goto(`patterns/menu-button/${framework}/demo/`);
await getMenuButton(page).waitFor();
// Wait for hydration (especially needed for Svelte)
if (framework === 'svelte') {
await waitForHydration(page);
}
const button = getMenuButton(page);
await button.focus();
await page.keyboard.press('Enter');
const menu = getMenu(page);
await expect(menu).toBeVisible();
// First item should be focused
const firstItem = getMenuItems(page).first();
await expect(firstItem).toBeFocused();
// Arrow navigation
await page.keyboard.press('ArrowDown');
const secondItem = getMenuItems(page).nth(1);
await expect(secondItem).toBeFocused();
await page.keyboard.press('Escape');
}
});
}); Testing Tools
- Vitest (opens in new tab) - Test runner for unit tests
- Testing Library (opens in new tab) - Framework-specific testing utilities (React, Vue, Svelte)
- Playwright (opens in new tab) - E2E testing (136 cross-framework tests)
- @axe-core/playwright (opens in new tab) - Automated accessibility testing
E2E tests: e2e/menu-button.spec.ts (opens in new tab)
See
testing-strategy.md
(opens in new tab) for full documentation.
Resources
- WAI-ARIA APG: Menu Button Pattern (opens in new tab)
- AI Implementation Guide (llm.md) (opens in new tab) - ARIA specs, keyboard support, test checklist