test(navbar): add massive scaling coverage for render and interaction stability

app/components/navbar.massive-scaling.test.tsx

@@ -0,0 +1,191 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { render, screen, fireEvent } from '@testing-library/react';
+import type { ReactNode } from 'react';
+import Navbar from './navbar';
+
+vi.mock('framer-motion', () => ({
+  motion: {
+    div: ({ children }: { children: ReactNode }) => <div>{children}</div>,
+  },
+}));
+
+vi.mock('lucide-react', () => ({
+  Menu: () => <div>MenuIcon</div>,
+  X: () => <div>CloseIcon</div>,
+  Activity: () => <div>ActivityIcon</div>,
+  Globe: () => <div>GlobeIcon</div>,
+  Sun: () => <div>SunIcon</div>,
+  Moon: () => <div>MoonIcon</div>,
+}));
+
+vi.mock('@/context/TranslationContext', () => ({
+  useTranslation: () => ({
+    t: (key: string) => {
+      const map: Record<string, string> = {
+        'navbar.home': 'Go to Home',
+        'navbar.menu_open': 'Open Menu',
+        'navbar.menu_close': 'Close Menu',
+        'navbar.theme_toggle': 'Toggle Theme',
+        'navbar.repo': 'GitHub Repo',
+        'navbar.compare': 'Compare',
+        'navbar.generator': 'Generator',
+        'navbar.burnout_radar': 'Burnout Radar',
+        'navbar.customization_studio': 'Customization Studio',
+      };
+
+      return map[key] ?? key;
+    },
+    language: 'en',
+    changeLanguage: vi.fn(),
+    isPending: false,
+  }),
+  LANGUAGE_LABELS: {
+    en: 'English',
+    hi: 'Hindi',
+  },
+}));
+
+vi.mock('@/hooks/useGlowEffect', () => ({
+  useGlowEffect: () => ({
+    shellRef: { current: null },
+    shellVars: {},
+    handleMouseEnter: vi.fn(),
+    handleMouseMove: vi.fn(),
+    handleMouseLeave: vi.fn(),
+  }),
+}));
+
+vi.mock('@/hooks/useKeyboardShortcuts', () => ({
+  useKeyboardShortcuts: vi.fn(),
+}));
+
+vi.mock('./theme-switch', () => ({
+  useThemeToggle: () => ({
+    isDark: false,
+    mounted: true,
+    toggleTheme: vi.fn(),
+  }),
+}));
+
+vi.mock('next/link', () => ({
+  default: ({
+    href,
+    children,
+    className,
+    onClick,
+    'aria-label': ariaLabel,
+  }: {
+    href: string;
+    children: ReactNode;
+    className?: string;
+    onClick?: () => void;
+    'aria-label'?: string;
+  }) => (
+    <a href={href} className={className} onClick={onClick} aria-label={ariaLabel}>
+      {children}
+    </a>
+  ),
+}));
+
+function mockMatchMedia(initialMatches = false) {
+  Object.defineProperty(window, 'matchMedia', {
+    writable: true,
+    value: vi.fn().mockImplementation((query: string) => ({
+      matches: initialMatches,
+      media: query,
+      onchange: null,
+      addListener: vi.fn(),
+      removeListener: vi.fn(),
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+      dispatchEvent: vi.fn(),
+    })),
+  });
+}
+
+describe('Navbar massive scaling', () => {
+  beforeEach(() => {
+    mockMatchMedia(false);
+
+    Object.defineProperty(window, 'localStorage', {
+      value: {
+        getItem: vi.fn(),
+        setItem: vi.fn(),
+        clear: vi.fn(),
+      },
+      writable: true,
+    });
+
+    document.documentElement.className = '';
+  });
+
+  it('renders repeatedly without memory or DOM instability', () => {
+    for (let i = 0; i < 200; i++) {
+      const { unmount } = render(<Navbar />);
+
+      expect(screen.getByRole('navigation')).toBeInTheDocument();
+
+      unmount();
+    }
+  });
+
+  it('handles high-volume menu toggle interactions', () => {
+    render(<Navbar />);
+
+    const button = screen.getByRole('button', {
+      name: /open menu/i,
+    });
+
+    for (let i = 0; i < 100; i++) {
+      fireEvent.click(button);
+    }
+
+    expect(screen.getByRole('navigation')).toBeInTheDocument();
+  });
+
+  it('preserves navigation link structure across repeated renders', () => {
+    const { container } = render(
+      <>
+        {Array.from({ length: 50 }).map((_, index) => (
+          <div key={index}>
+            <Navbar />
+          </div>
+        ))}
+      </>
+    );
+
+    const navs = container.querySelectorAll('nav');
+
+    expect(navs.length).toBe(50);
+  });
+
+  it('maintains acceptable render performance under heavy mount cycles', () => {
+    const start = performance.now();
+
+    for (let i = 0; i < 100; i++) {
+      const { unmount } = render(<Navbar />);
+      unmount();
+    }
+
+    const duration = performance.now() - start;
+
+    expect(duration).toBeLessThan(5000);
+  });
+
+  it('keeps mobile menu functionality stable after extensive interaction cycles', () => {
+    render(<Navbar />);
+
+    const menuButton = screen.getByRole('button', {
+      name: /open menu/i,
+    });
+
+    for (let i = 0; i < 50; i++) {
+      fireEvent.click(menuButton);
+      fireEvent.click(menuButton);
+    }
+
+    expect(screen.getByRole('navigation')).toBeInTheDocument();
+
+    expect(menuButton).toHaveAttribute('aria-expanded');
+  });
+});