Mo tests

frontend/package.json

@@ -7,7 +7,9 @@
      "dev": "vite",
      "build": "tsc -b && vite build",
      "lint": "eslint .",
-    "preview": "vite preview"
+     "preview": "vite preview",
+     "test": "vitest run --config vitest.config.ts",
+     "test:watch": "vitest --config vitest.config.ts"
    },
    "dependencies": {
      "@tanstack/react-query": "^5.90.21",
@@ -17,6 +19,9 @@
    },
    "devDependencies": {
      "@eslint/js": "^9.39.1",
+     "@testing-library/jest-dom": "^6.9.1",
+     "@testing-library/react": "^16.3.2",
+     "@testing-library/user-event": "^14.6.1",
      "@types/node": "^24.10.1",
      "@types/react": "^19.2.7",
      "@types/react-dom": "^19.2.3",
@@ -25,8 +30,11 @@
      "eslint-plugin-react-hooks": "^7.0.1",
      "eslint-plugin-react-refresh": "^0.4.24",
      "globals": "^16.5.0",
+     "jsdom": "^28.0.0",
      "typescript": "~5.9.3",
      "typescript-eslint": "^8.48.0",
-    "vite": "^7.3.1"
+     "vite": "^7.3.1",
+     "vitest": "^4.0.18"
    }
  }
+ 

frontend/src/tests/app.test.tsx

@@ -0,0 +1,46 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import { MemoryRouter } from 'react-router-dom';
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
+import App from '../App';
+
+let fetchMock: ReturnType<typeof vi.fn>;
+
+beforeEach(() => {
+  fetchMock = vi.fn();
+  globalThis.fetch = fetchMock as unknown as typeof fetch;
+  fetchMock.mockReturnValue(
+    Promise.resolve({ ok: true, json: () => Promise.resolve([]) } as Response)
+  );
+});
+
+afterEach(() => {
+  vi.restoreAllMocks();
+});
+
+const renderApp = (initialRoute = '/') => {
+  const queryClient = new QueryClient({
+    defaultOptions: { queries: { retry: false } },
+  });
+
+  return render(
+    <QueryClientProvider client={queryClient}>
+      <MemoryRouter initialEntries={[initialRoute]}>
+        <App />
+      </MemoryRouter>
+    </QueryClientProvider>
+  );
+};
+
+describe('App routing', () => {
+
+  it('should render the Home page on "/"', async () => {
+    renderApp('/');
+    expect(await screen.findByText('kohngrüti')).toBeInTheDocument();
+  });
+
+  it('should redirect unknown routes to Home', async () => {
+    renderApp('/some/random/path');
+    expect(await screen.findByText('kohngrüti')).toBeInTheDocument();
+  });
+});

frontend/src/tests/button.test.tsx

@@ -0,0 +1,27 @@
+import { describe, it, expect, vi } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import Button from '../components/button';
+
+describe('Button', () => {
+
+  it('should render with the provided label', () => {
+    render(<Button onClick={() => {}} isLoading={false} label="Click Me" />);
+    expect(screen.getByRole('button', { name: 'Click Me' })).toBeInTheDocument();
+  });
+
+  it('should show "Working..." when isLoading is true', () => {
+    render(<Button onClick={() => {}} isLoading={true} label="Click Me" />);
+    expect(screen.getByRole('button', { name: 'Working...' })).toBeInTheDocument();
+  });
+
+  it('should call onClick when clicked', async () => {
+    const handleClick = vi.fn();
+    render(<Button onClick={handleClick} isLoading={false} label="Click Me" />);
+
+    await userEvent.click(screen.getByRole('button'));
+
+    expect(handleClick).toHaveBeenCalledOnce();
+  });
+
+});

frontend/src/tests/setup.ts

@@ -0,0 +1 @@
+import '@testing-library/jest-dom/vitest';

frontend/src/tests/stickies.test.tsx

@@ -0,0 +1,107 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { render, screen, waitFor } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import Stickies from '../components/stickies';
+import { createTestWrapper } from './test-wrapper';
+
+const MOCK_STICKIES = [
+  { id: 'note_001', text: 'Login flow feels confusing', x: 193, y: 191, author: 'user_5', color: 'yellow' },
+  { id: 'note_002', text: 'Export takes too long', x: 798, y: 211, author: 'user_2', color: 'green' },
+];
+
+const MOCK_CLUSTERS = [
+  { label: 'Auth Issues', noteIds: ['note_001'] },
+  { label: 'Export Issues', noteIds: ['note_002'] },
+];
+
+let fetchMock: ReturnType<typeof vi.fn>;
+
+beforeEach(() => {
+  fetchMock = vi.fn();
+  globalThis.fetch = fetchMock as unknown as typeof fetch;
+});
+
+afterEach(() => {
+  vi.restoreAllMocks();
+});
+
+const mockFetchOk = (data: unknown) =>
+  Promise.resolve({ ok: true, json: () => Promise.resolve(data) } as Response);
+
+const mockFetchFail = () =>
+  Promise.resolve({ ok: false, status: 500, json: () => Promise.resolve({}) } as Response);
+
+
+describe('Stickies', () => {
+
+  it('should show a loading indicator while fetching notes', () => {
+    // Fetch never resolves — stays in loading state
+    fetchMock.mockReturnValue(new Promise(() => {}));
+    const { Wrapper } = createTestWrapper();
+
+    render(<Stickies />, { wrapper: Wrapper });
+
+    expect(screen.getByText('Loading...')).toBeInTheDocument();
+  });
+
+  it('should render all sticky notes after fetch succeeds', async () => {
+    fetchMock.mockReturnValue(mockFetchOk(MOCK_STICKIES));
+    const { Wrapper } = createTestWrapper();
+
+    render(<Stickies />, { wrapper: Wrapper });
+
+    expect(await screen.findByText('Login flow feels confusing')).toBeInTheDocument();
+    expect(screen.getByText('Export takes too long')).toBeInTheDocument();
+  });
+
+  it('should render the cluster button', async () => {
+    fetchMock.mockReturnValue(mockFetchOk(MOCK_STICKIES));
+    const { Wrapper } = createTestWrapper();
+
+    render(<Stickies />, { wrapper: Wrapper });
+
+    expect(await screen.findByRole('button', { name: 'Group Stickies By Topic' })).toBeInTheDocument();
+  });
+
+  it('should show an error message when fetching notes fails', async () => {
+    fetchMock.mockReturnValue(mockFetchFail());
+    const { Wrapper } = createTestWrapper();
+
+    render(<Stickies />, { wrapper: Wrapper });
+
+    expect(await screen.findByText(/Error:/)).toBeInTheDocument();
+  });
+
+  it('should show cluster labels after clustering succeeds', async () => {
+    // First call = GET notes, second call = POST cluster
+    fetchMock
+      .mockReturnValueOnce(mockFetchOk(MOCK_STICKIES))
+      .mockReturnValueOnce(mockFetchOk(MOCK_CLUSTERS));
+
+    const { Wrapper } = createTestWrapper();
+    render(<Stickies />, { wrapper: Wrapper });
+
+    const btn = await screen.findByRole('button', { name: 'Group Stickies By Topic' });
+    await userEvent.click(btn);
+
+    await waitFor(() => {
+      expect(screen.getByText('Auth Issues')).toBeInTheDocument();
+      expect(screen.getByText('Export Issues')).toBeInTheDocument();
+    });
+  });
+
+  it('should still render sticky note text inside clusters', async () => {
+    fetchMock
+      .mockReturnValueOnce(mockFetchOk(MOCK_STICKIES))
+      .mockReturnValueOnce(mockFetchOk(MOCK_CLUSTERS));
+
+    const { Wrapper } = createTestWrapper();
+    render(<Stickies />, { wrapper: Wrapper });
+
+    const btn = await screen.findByRole('button', { name: 'Group Stickies By Topic' });
+    await userEvent.click(btn);
+
+    expect(await screen.findByText('Login flow feels confusing')).toBeInTheDocument();
+    expect(screen.getByText('Export takes too long')).toBeInTheDocument();
+  });
+});

frontend/tsconfig.app.json

@@ -5,7 +5,7 @@
     "useDefineForClassFields": true,
     "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "module": "ESNext",
-    "types": ["vite/client"],
+    "types": ["vite/client", "@testing-library/jest-dom"],
     "skipLibCheck": true,
 
     /* Bundler mode */

frontend/vitest.config.ts

@@ -0,0 +1,11 @@
+import { defineConfig } from 'vitest/config';
+import react from '@vitejs/plugin-react';
+
+export default defineConfig({
+  plugins: [react()],
+  test: {
+    environment: 'jsdom',
+    setupFiles: './src/tests/setup.ts',
+    globals: true,
+  },
+});