feat: KitchenStock light UI, Gemma 31B AI, supermarket store filters & 130+ vegan products

tests/unit/currency.test.ts

@@ -0,0 +1,27 @@
+import { describe, it, expect } from 'vitest';
+import { formatCurrency, calculateBasePrice, calculateStockValueCents } from '@/lib/formatting/currency';
+
+describe('Currency & Stock Value Formatting', () => {
+  it('formats integer cents into German Euro currency string', () => {
+    expect(formatCurrency(249)).toContain('2,49');
+    expect(formatCurrency(0)).toContain('0,00');
+    expect(formatCurrency(1299)).toContain('12,99');
+  });
+
+  it('calculates full package stock value correctly', () => {
+    // 2 packages @ 1,99 € (199 Cent) = 398 Cent
+    expect(calculateStockValueCents(2, 1, 199)).toBe(398);
+  });
+
+  it('calculates partial package stock value correctly (750g of 1000g @ 1,29 € = 0,97 €)', () => {
+    // 750g / 1000g * 129 Cent = 96.75 Cent -> rounded to 97 Cent
+    expect(calculateStockValueCents(750, 1000, 129)).toBe(97);
+  });
+
+  it('calculates base price (Grundpreis) per 1kg for grams', () => {
+    // 500g Barilla Spaghetti @ 1,89 € (189 Cent) -> 3.78 € / kg (378 Cent)
+    const base = calculateBasePrice(189, 500, 'g');
+    expect(base.basePriceCents).toBe(378);
+    expect(base.basePriceUnit).toBe('1 kg');
+  });
+});