Add additional unit tests

src/components/BarcodeScannerView.test.tsx

@@ -0,0 +1,40 @@
+import React from 'react';
+import { render, screen } from '@testing-library/react';
+import { describe, expect, it, vi } from 'vitest';
+import { BarcodeScannerView } from './BarcodeScannerView';
+
+const mockUseBarcodeScanner = vi.fn();
+
+vi.mock('../hooks/useBarcodeScanner', () => ({
+  useBarcodeScanner: () => mockUseBarcodeScanner(),
+}));
+
+describe('BarcodeScannerView', () => {
+  it('notifies when a barcode is detected and shows success alert', () => {
+    const onDetected = vi.fn();
+    const videoRef = { current: document.createElement('video') } as React.RefObject<HTMLVideoElement>;
+
+    mockUseBarcodeScanner.mockReturnValue({
+      videoRef,
+      result: { code: '12345', error: null },
+    });
+
+    render(<BarcodeScannerView onDetected={onDetected} />);
+
+    expect(screen.getByText(/detected 12345/i)).toBeVisible();
+    expect(onDetected).toHaveBeenCalledWith('12345');
+  });
+
+  it('renders an error alert when scanning fails', () => {
+    const videoRef = { current: document.createElement('video') } as React.RefObject<HTMLVideoElement>;
+
+    mockUseBarcodeScanner.mockReturnValue({
+      videoRef,
+      result: { code: '', error: 'Camera access denied' },
+    });
+
+    render(<BarcodeScannerView />);
+
+    expect(screen.getByText(/camera access denied/i)).toBeVisible();
+  });
+});

src/components/PickItemRow.test.tsx

@@ -145,4 +145,54 @@ describe('PickItemRow', () => {
 
     expect(screen.getByRole('dialog', { name: baseProduct.name })).toBeVisible();
   });
+
+  it('uses inline controls on wide screens', async () => {
+    const onIncrement = vi.fn();
+    const onDecrement = vi.fn();
+    const onToggleCarton = vi.fn();
+    const user = userEvent.setup();
+
+    render(
+      <PickItemRow
+        item={baseItem}
+        product={baseProduct}
+        onIncrementQuantity={onIncrement}
+        onDecrementQuantity={onDecrement}
+        onToggleCarton={onToggleCarton}
+        onStatusChange={vi.fn()}
+        onDelete={vi.fn()}
+      />,
+    );
+
+    await user.click(screen.getByRole('button', { name: /switch to carton packaging/i }));
+    await user.click(screen.getByRole('button', { name: /increase quantity/i }));
+    await user.click(screen.getByRole('button', { name: /decrease quantity/i }));
+
+    expect(onToggleCarton).toHaveBeenCalledTimes(1);
+    expect(onIncrement).toHaveBeenCalledTimes(1);
+    expect(onDecrement).toHaveBeenCalledTimes(1);
+  });
+
+  it('opens controls from keyboard interaction on narrow screens', async () => {
+    mockMatchMedia(true);
+    const user = userEvent.setup();
+
+    render(
+      <PickItemRow
+        item={baseItem}
+        product={baseProduct}
+        onIncrementQuantity={vi.fn()}
+        onDecrementQuantity={vi.fn()}
+        onToggleCarton={vi.fn()}
+        onStatusChange={vi.fn()}
+        onDelete={vi.fn()}
+      />,
+    );
+
+    const row = screen.getByRole('button', { name: /test product/i });
+    row.focus();
+    await user.keyboard('{Enter}');
+
+    expect(screen.getByRole('dialog', { name: baseProduct.name })).toBeVisible();
+  });
 });

src/components/ProductRow.test.tsx

@@ -1,4 +1,5 @@
 import { render, screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
 import { describe, expect, it, vi } from 'vitest';
 import { ProductRow } from './ProductRow';
 import { Product } from '../models/Product';
@@ -32,4 +33,62 @@ describe('ProductRow', () => {
     expect(screen.getByText(/Barcode: 123456/)).toBeInTheDocument();
     expect(screen.queryByText(/bottle/i)).not.toBeInTheDocument();
   });
+
+  it('saves edits and closes the form', async () => {
+    const user = userEvent.setup();
+    const onSave = vi.fn();
+
+    render(
+      <ProductRow product={product} categories={categories} onSave={onSave} onDelete={vi.fn()} />,
+    );
+
+    await user.click(screen.getByLabelText(/edit sparkling water/i));
+    await user.clear(screen.getByLabelText(/name/i));
+    await user.type(screen.getByLabelText(/name/i), 'Still Water');
+    await user.click(screen.getByLabelText(/category/i));
+    await user.selectOptions(screen.getByLabelText(/category/i), 'Snacks');
+    await user.click(screen.getByLabelText(/save product/i));
+
+    expect(onSave).toHaveBeenCalledWith('prod-1', {
+      name: 'Still Water',
+      category: 'Snacks',
+      barcode: '123456',
+    });
+    expect(screen.queryByLabelText(/save product/i)).not.toBeInTheDocument();
+  });
+
+  it('surfaces validation errors from duplicate constraints', async () => {
+    const user = userEvent.setup();
+    const onSave = vi.fn().mockRejectedValueOnce(Object.assign(new Error('dup'), { name: 'DuplicateNameError' }))
+      .mockRejectedValueOnce(Object.assign(new Error('dup'), { name: 'DuplicateBarcodeError' }));
+
+    render(
+      <ProductRow product={product} categories={categories} onSave={onSave} onDelete={vi.fn()} />,
+    );
+
+    await user.click(screen.getByLabelText(/edit sparkling water/i));
+    await user.clear(screen.getByLabelText(/name/i));
+    await user.type(screen.getByLabelText(/name/i), 'Sparkling Water');
+    await user.click(screen.getByLabelText(/save product/i));
+
+    expect(await screen.findByText(/already exists/i)).toBeVisible();
+
+    await user.type(screen.getByLabelText(/barcode/i), '999');
+    await user.click(screen.getByLabelText(/save product/i));
+
+    expect(await screen.findByText(/already assigned/i)).toBeVisible();
+  });
+
+  it('allows clearing and scanning a new barcode', async () => {
+    const user = userEvent.setup();
+
+    render(
+      <ProductRow product={product} categories={categories} onSave={vi.fn()} onDelete={vi.fn()} />,
+    );
+
+    await user.click(screen.getByLabelText(/edit sparkling water/i));
+    await user.click(screen.getByRole('button', { name: /clear/i }));
+
+    expect(screen.getByRole('button', { name: /scan barcode/i })).toBeVisible();
+  });
 });