Groceries: private tracker at /trackers/groceries (stores, products, price history per store, favorites, cheapest highlighted); seeded AH, Jumbo, Lidl, Plus

src/lib/server/groceries.test.ts

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+import { describe, expect, it } from 'vitest';
+import { parseCents, parseSize, priceInput, unitPriceCents } from './groceries';
+import { cheapestStores, formatCents } from '../groceries';
+
+describe('groceries helpers', () => {
+	it('parses prices into cents', () => {
+		expect(parseCents('1,79')).toBe(179);
+		expect(parseCents('€ 2.5')).toBe(250);
+		expect(parseCents('3')).toBe(300);
+		expect(parseCents('abc')).toBeNull();
+		expect(parseCents('1,234')).toBeNull();
+	});
+	it('parses pack sizes', () => {
+		expect(parseSize('1 L')).toEqual({ amount: 1, unit: 'l' });
+		expect(parseSize('6 x 1 L')).toEqual({ amount: 6, unit: 'l' });
+		expect(parseSize('500 g')).toEqual({ amount: 0.5, unit: 'kg' });
+		expect(parseSize('750ml')).toEqual({ amount: 0.75, unit: 'l' });
+		expect(parseSize('4 stuks')).toEqual({ amount: 4, unit: 'piece' });
+		expect(parseSize('1,5 liter')).toEqual({ amount: 1.5, unit: 'l' });
+		expect(parseSize('a bunch')).toBeNull();
+	});
+	it('computes unit prices', () => {
+		expect(unitPriceCents(479, 6)).toBe(80);
+		expect(unitPriceCents(100, null)).toBeNull();
+	});
+	it('validates price input', () => {
+		expect(priceInput.safeParse({ price: '1,29' }).data?.price).toBe(129);
+		expect(priceInput.safeParse({ price: 'x' }).success).toBe(false);
+		expect(priceInput.safeParse({ price: '1', url: '' }).success).toBe(true);
+	});
+	it('finds the cheapest store', () => {
+		const p = (storeId: number, priceCents: number, unitPriceCents: number | null) => ({
+			storeId,
+			priceCents,
+			unitPriceCents,
+			promo: false,
+			observedAt: new Date()
+		});
+		expect([...cheapestStores([p(1, 179, 179), p(2, 129, 129)])]).toEqual([2]);
+		expect([...cheapestStores([p(1, 479, 80), p(2, 129, 129)])]).toEqual([1]);
+		expect([...cheapestStores([p(1, 479, null), p(2, 129, 129)])]).toEqual([2]);
+		expect(cheapestStores([p(1, 100, null)]).size).toBe(0);
+		expect(formatCents(179).replace(/\s/g, ' ')).toBe('€ 1,79');
+	});
+});