fix: oprava pádu při zdvojeném menu

server/src/tests/service.pruneChoices.test.ts

@@ -0,0 +1,53 @@
+import { pruneStaleFoodChoices } from '../service';
+import { LunchChoices, RestaurantDayMenuMap } from '../../../types/gen/types.gen';
+
+// Pomocná fabrika menu s daným počtem jídel pro TECHTOWER.
+const menusWithTechTowerFoods = (count: number): RestaurantDayMenuMap => ({
+    TECHTOWER: {
+        lastUpdate: 0,
+        closed: false,
+        food: Array.from({ length: count }, (_, i) => ({ name: `Jídlo ${i}` })),
+    },
+} as unknown as RestaurantDayMenuMap);
+
+describe('pruneStaleFoodChoices', () => {
+    test('odebere index jídla, který v aktuálním menu již neexistuje', () => {
+        const choices: LunchChoices = {
+            TECHTOWER: { alice: { selectedFoods: [0, 9] } },
+        };
+        const mutated = pruneStaleFoodChoices(choices, menusWithTechTowerFoods(5));
+        expect(mutated).toBe(true);
+        expect(choices.TECHTOWER!.alice.selectedFoods).toEqual([0]);
+    });
+
+    test('nechá platné indexy beze změny a vrátí false', () => {
+        const choices: LunchChoices = {
+            TECHTOWER: { alice: { selectedFoods: [0, 4] } },
+        };
+        const mutated = pruneStaleFoodChoices(choices, menusWithTechTowerFoods(5));
+        expect(mutated).toBe(false);
+        expect(choices.TECHTOWER!.alice.selectedFoods).toEqual([0, 4]);
+    });
+
+    test('u prázdného menu (zavřeno / neúspěšné načtení) volby nemaže', () => {
+        const choices: LunchChoices = {
+            TECHTOWER: { alice: { selectedFoods: [3] } },
+        };
+        const mutated = pruneStaleFoodChoices(choices, menusWithTechTowerFoods(0));
+        expect(mutated).toBe(false);
+        expect(choices.TECHTOWER!.alice.selectedFoods).toEqual([3]);
+    });
+
+    test('očistí volby více uživatelů najednou', () => {
+        const choices: LunchChoices = {
+            TECHTOWER: {
+                alice: { selectedFoods: [7] },
+                bob: { selectedFoods: [1, 2] },
+            },
+        };
+        const mutated = pruneStaleFoodChoices(choices, menusWithTechTowerFoods(5));
+        expect(mutated).toBe(true);
+        expect(choices.TECHTOWER!.alice.selectedFoods).toEqual([]);
+        expect(choices.TECHTOWER!.bob.selectedFoods).toEqual([1, 2]);
+    });
+});