APG Patterns
日本語 GitHub
日本語 GitHub

Toggle Button

A two-state button that can be either "pressed" or "not pressed".

🤖 AI Implementation Guide

Demo

Open demo only →

Accessibility Features

WAI-ARIA Roles

WAI-ARIA States

aria-pressed

Indicates the current pressed state of the toggle button.

Values true | false (tri-state buttons may also use "mixed")
Required Yes (for toggle buttons)
Default initialPressed prop (default: false)
Change Trigger Click, Enter, Space
Reference aria-pressed (opens in new tab)

Keyboard Support

Key Action
Space Toggle the button state
Enter Toggle the button state

Source Code

ToggleButton.tsx
import { cn } from '@/lib/utils';
import { useCallback, useState } from 'react';

export interface ToggleButtonProps extends Omit<
  React.ButtonHTMLAttributes<HTMLButtonElement>,
  'onClick' | 'type' | 'aria-pressed' | 'onToggle'
> {
  /** Initial pressed state */
  initialPressed?: boolean;
  /** Button label text */
  children: React.ReactNode;
  /** Callback fired when toggle state changes */
  onPressedChange?: (pressed: boolean) => void;
  /** Custom indicator for pressed state (default: "●") */
  pressedIndicator?: React.ReactNode;
  /** Custom indicator for unpressed state (default: "○") */
  unpressedIndicator?: React.ReactNode;
}

export const ToggleButton: React.FC<ToggleButtonProps> = ({
  initialPressed = false,
  children,
  onPressedChange,
  pressedIndicator = '●',
  unpressedIndicator = '○',
  className = '',
  ...buttonProps
}) => {
  const [pressed, setPressed] = useState(initialPressed);

  const handleClick = useCallback(() => {
    setPressed(!pressed);
    onPressedChange?.(!pressed);
  }, [pressed, onPressedChange]);

  return (
    <button
      type="button"
      {...buttonProps}
      className={cn('apg-toggle-button', className)}
      aria-pressed={pressed}
      onClick={handleClick}
    >
      <span className="apg-toggle-button-content">{children}</span>
      <span className="apg-toggle-indicator" aria-hidden="true">
        {pressed ? pressedIndicator : unpressedIndicator}
      </span>
    </button>
  );
};

export default ToggleButton;

Usage

Example
import { ToggleButton } from './ToggleButton';
import { Volume2, VolumeOff } from 'lucide-react';

function App() {
  return (
    <ToggleButton
      initialPressed={false}
      onPressedChange={(pressed) => console.log('Muted:', pressed)}
      pressedIndicator={<VolumeOff size={20} />}
      unpressedIndicator={<Volume2 size={20} />}
    >
      Mute
    </ToggleButton>
  );
}

API

Prop Type Default Description
initialPressed boolean false Initial pressed state
onPressedChange (pressed: boolean) => void - Callback when state changes
pressedIndicator ReactNode "●" Custom indicator for pressed state
unpressedIndicator ReactNode "○" Custom indicator for unpressed state
children ReactNode - Button label

All other props are passed to the underlying <button> element.

Testing

Tests verify APG compliance across keyboard interaction, ARIA attributes, and accessibility requirements. The Toggle Button component uses a two-layer testing strategy.

Testing Strategy

Unit Tests (Testing Library)

Verify component rendering and interactions using framework-specific Testing Library utilities. These tests ensure correct component behavior in isolation.

  • HTML structure and element hierarchy
  • Initial attribute values (aria-pressed, type)
  • Click event handling and state toggling
  • CSS class application

E2E Tests (Playwright)

Verify component behavior in a real browser environment across all four frameworks. These tests cover interactions that require full browser context.

  • Keyboard interactions (Space, Enter)
  • aria-pressed state toggling
  • Disabled state behavior
  • Focus management and Tab navigation
  • Cross-framework consistency

Test Categories

High Priority: APG Keyboard Interaction (E2E)

Test Description
Space key toggles Pressing Space toggles the button state
Enter key toggles Pressing Enter toggles the button state
Tab navigation Tab key moves focus between buttons
Disabled Tab skip Disabled buttons are skipped in Tab order

High Priority: APG ARIA Attributes (E2E)

Test Description
role="button" Has implicit button role (via <button>)
aria-pressed initial Initial state is aria-pressed="false"
aria-pressed toggle Click changes aria-pressed to true
type="button" Explicit button type prevents form submission
disabled state Disabled buttons don't change state on click

Medium Priority: Accessibility (E2E)

Test Description
axe violations No WCAG 2.1 AA violations (via jest-axe)
accessible name Button has an accessible name from content

Low Priority: HTML Attribute Inheritance (Unit)

Test Description
className merge Custom classes are merged with component classes
data-* attributes Custom data attributes are passed through

Testing Tools

See testing-strategy.md (opens in new tab) for full documentation.

ToggleButton.test.tsx
import { render, screen } from '@testing-library/react';
import userEvent from '@testing-library/user-event';
import { axe } from 'jest-axe';
import { describe, expect, it, vi } from 'vitest';
import { ToggleButton } from './ToggleButton';

describe('ToggleButton', () => {
  // 🔴 High Priority: APG Core Compliance
  describe('APG: Keyboard Interaction', () => {
    it('toggles with Space key', async () => {
      const user = userEvent.setup();
      render(<ToggleButton>Mute</ToggleButton>);
      const button = screen.getByRole('button');

      expect(button).toHaveAttribute('aria-pressed', 'false');
      button.focus();
      await user.keyboard(' ');
      expect(button).toHaveAttribute('aria-pressed', 'true');
    });

    it('toggles with Enter key', async () => {
      const user = userEvent.setup();
      render(<ToggleButton>Mute</ToggleButton>);
      const button = screen.getByRole('button');

      expect(button).toHaveAttribute('aria-pressed', 'false');
      button.focus();
      await user.keyboard('{Enter}');
      expect(button).toHaveAttribute('aria-pressed', 'true');
    });

    it('can move focus with Tab key', async () => {
      const user = userEvent.setup();
      render(
        <>
          <ToggleButton>Button 1</ToggleButton>
          <ToggleButton>Button 2</ToggleButton>
        </>
      );

      await user.tab();
      expect(screen.getByRole('button', { name: 'Button 1' })).toHaveFocus();
      await user.tab();
      expect(screen.getByRole('button', { name: 'Button 2' })).toHaveFocus();
    });

    it('skips with Tab key when disabled', async () => {
      const user = userEvent.setup();
      render(
        <>
          <ToggleButton>Button 1</ToggleButton>
          <ToggleButton disabled>Button 2</ToggleButton>
          <ToggleButton>Button 3</ToggleButton>
        </>
      );

      await user.tab();
      expect(screen.getByRole('button', { name: 'Button 1' })).toHaveFocus();
      await user.tab();
      expect(screen.getByRole('button', { name: 'Button 3' })).toHaveFocus();
    });
  });

  describe('APG: ARIA Attributes', () => {
    it('has implicit role="button"', () => {
      render(<ToggleButton>Mute</ToggleButton>);
      expect(screen.getByRole('button')).toBeInTheDocument();
    });

    it('has aria-pressed="false" in initial state', () => {
      render(<ToggleButton>Mute</ToggleButton>);
      const button = screen.getByRole('button');
      expect(button).toHaveAttribute('aria-pressed', 'false');
    });

    it('changes to aria-pressed="true" after click', async () => {
      const user = userEvent.setup();
      render(<ToggleButton>Mute</ToggleButton>);
      const button = screen.getByRole('button');

      expect(button).toHaveAttribute('aria-pressed', 'false');
      await user.click(button);
      expect(button).toHaveAttribute('aria-pressed', 'true');
    });

    it('has type="button"', () => {
      render(<ToggleButton>Mute</ToggleButton>);
      const button = screen.getByRole('button');
      expect(button).toHaveAttribute('type', 'button');
    });

    it('cannot change aria-pressed when disabled', async () => {
      const user = userEvent.setup();
      render(<ToggleButton disabled>Mute</ToggleButton>);
      const button = screen.getByRole('button');

      expect(button).toHaveAttribute('aria-pressed', 'false');
      await user.click(button);
      expect(button).toHaveAttribute('aria-pressed', 'false');
    });
  });

  // 🟡 Medium Priority: Accessibility Validation
  describe('Accessibility', () => {
    it('has no WCAG 2.1 AA violations', async () => {
      const { container } = render(<ToggleButton>Mute</ToggleButton>);
      const results = await axe(container);
      expect(results).toHaveNoViolations();
    });

    it('has accessible name', () => {
      render(<ToggleButton>Mute Audio</ToggleButton>);
      expect(screen.getByRole('button', { name: /Mute Audio/i })).toBeInTheDocument();
    });
  });

  describe('Props', () => {
    it('renders in pressed state with initialPressed=true', () => {
      render(<ToggleButton initialPressed>Mute</ToggleButton>);
      const button = screen.getByRole('button');
      expect(button).toHaveAttribute('aria-pressed', 'true');
    });

    it('calls onPressedChange when state changes', async () => {
      const handlePressedChange = vi.fn();
      const user = userEvent.setup();
      render(<ToggleButton onPressedChange={handlePressedChange}>Mute</ToggleButton>);

      await user.click(screen.getByRole('button'));
      expect(handlePressedChange).toHaveBeenCalledWith(true);

      await user.click(screen.getByRole('button'));
      expect(handlePressedChange).toHaveBeenCalledWith(false);
    });
  });

  describe('Custom Indicators', () => {
    it('displays default ●/○ indicator', () => {
      render(<ToggleButton>Mute</ToggleButton>);
      const button = screen.getByRole('button');
      const indicator = button.querySelector('.apg-toggle-indicator');
      expect(indicator).toHaveTextContent('○');
    });

    it('can set custom indicator with pressedIndicator', () => {
      render(
        <ToggleButton initialPressed pressedIndicator="🔇">
          Mute
        </ToggleButton>
      );
      const button = screen.getByRole('button');
      const indicator = button.querySelector('.apg-toggle-indicator');
      expect(indicator).toHaveTextContent('🔇');
    });

    it('can set custom indicator with unpressedIndicator', () => {
      render(<ToggleButton unpressedIndicator="🔊">Mute</ToggleButton>);
      const button = screen.getByRole('button');
      const indicator = button.querySelector('.apg-toggle-indicator');
      expect(indicator).toHaveTextContent('🔊');
    });

    it('switches custom indicator on toggle', async () => {
      const user = userEvent.setup();
      render(
        <ToggleButton pressedIndicator="🔇" unpressedIndicator="🔊">
          Mute
        </ToggleButton>
      );
      const button = screen.getByRole('button');
      const indicator = button.querySelector('.apg-toggle-indicator');

      expect(indicator).toHaveTextContent('🔊');
      await user.click(button);
      expect(indicator).toHaveTextContent('🔇');
      await user.click(button);
      expect(indicator).toHaveTextContent('🔊');
    });

    it('can pass ReactNode as custom indicator', () => {
      render(
        <ToggleButton initialPressed pressedIndicator={<span data-testid="custom-icon">X</span>}>
          Mute
        </ToggleButton>
      );
      expect(screen.getByTestId('custom-icon')).toBeInTheDocument();
    });

    it('maintains aria-hidden with custom indicator', () => {
      render(
        <ToggleButton pressedIndicator="🔇" unpressedIndicator="🔊">
          Mute
        </ToggleButton>
      );
      const button = screen.getByRole('button');
      const indicator = button.querySelector('.apg-toggle-indicator');
      expect(indicator).toHaveAttribute('aria-hidden', 'true');
    });

    it('has no axe violations with custom indicator', async () => {
      const { container } = render(
        <ToggleButton pressedIndicator="🔇" unpressedIndicator="🔊">
          Mute
        </ToggleButton>
      );
      const results = await axe(container);
      expect(results).toHaveNoViolations();
    });
  });

  // 🟢 Low Priority: Extensibility
  describe('HTML Attribute Inheritance', () => {
    it('merges className correctly', () => {
      render(<ToggleButton className="custom-class">Mute</ToggleButton>);
      const button = screen.getByRole('button');
      expect(button).toHaveClass('custom-class');
      expect(button).toHaveClass('apg-toggle-button');
    });

    it('inherits data-* attributes', () => {
      render(<ToggleButton data-testid="custom-toggle">Mute</ToggleButton>);
      expect(screen.getByTestId('custom-toggle')).toBeInTheDocument();
    });

    it('works correctly with React node children', () => {
      render(
        <ToggleButton>
          <span>Icon</span> Text
        </ToggleButton>
      );
      const button = screen.getByRole('button');
      expect(button).toHaveTextContent('Icon');
      expect(button).toHaveTextContent('Text');
    });
  });
});

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