Add comprehensive test suite and update configuration

- Add Jest testing framework configuration
- Add test files for services, types, and utilities
- Update package.json with Jest dependencies and test scripts
- Enhance pre-commit checks to include testing
- Add proper environment validation and error handling in mailgun service

utils/__tests__/schedule.test.ts

@@ -0,0 +1,223 @@
+import { generateSchedule, generateReminderSchedule } from '../schedule';
+import { Medication, Frequency, CustomReminder } from '../../types';
+
+describe('Schedule Utilities', () => {
+  const baseDate = new Date('2024-01-15T12:00:00.000Z');
+
+  describe('generateSchedule', () => {
+    const createMockMedication = (
+      overrides: Partial<Medication> = {}
+    ): Medication => ({
+      _id: 'med-1',
+      _rev: 'rev-1',
+      name: 'Test Medication',
+      dosage: '10mg',
+      frequency: Frequency.Daily,
+      startTime: '08:00',
+      notes: '',
+      ...overrides,
+    });
+
+    test('should return empty array for empty medications', () => {
+      const schedule = generateSchedule([], baseDate);
+      expect(schedule).toEqual([]);
+    });
+
+    test('should generate one dose for daily frequency', () => {
+      const medication = createMockMedication({
+        frequency: Frequency.Daily,
+      });
+
+      const schedule = generateSchedule([medication], baseDate);
+
+      expect(schedule).toHaveLength(1);
+      expect(schedule[0].medicationId).toBe('med-1');
+      expect(schedule[0].scheduledTime).toBeInstanceOf(Date);
+    });
+
+    test('should generate two doses for twice daily frequency', () => {
+      const medication = createMockMedication({
+        frequency: Frequency.TwiceADay,
+      });
+
+      const schedule = generateSchedule([medication], baseDate);
+
+      expect(schedule).toHaveLength(2);
+      expect(schedule[0].medicationId).toBe('med-1');
+      expect(schedule[1].medicationId).toBe('med-1');
+    });
+
+    test('should generate three doses for three times daily frequency', () => {
+      const medication = createMockMedication({
+        frequency: Frequency.ThreeTimesADay,
+      });
+
+      const schedule = generateSchedule([medication], baseDate);
+
+      expect(schedule).toHaveLength(3);
+    });
+
+    test('should handle EveryXHours frequency', () => {
+      const medication = createMockMedication({
+        frequency: Frequency.EveryXHours,
+        hoursBetween: 6,
+      });
+
+      const schedule = generateSchedule([medication], baseDate);
+
+      expect(schedule.length).toBeGreaterThan(0);
+      expect(schedule.length).toBeLessThanOrEqual(24);
+    });
+
+    test('should sort doses by time', () => {
+      const medications = [
+        createMockMedication({
+          _id: 'med-1',
+          startTime: '18:00',
+        }),
+        createMockMedication({
+          _id: 'med-2',
+          startTime: '08:00',
+        }),
+      ];
+
+      const schedule = generateSchedule(medications, baseDate);
+
+      expect(schedule).toHaveLength(2);
+      // Should be sorted by time
+      expect(schedule[0].scheduledTime.getTime()).toBeLessThanOrEqual(
+        schedule[1].scheduledTime.getTime()
+      );
+    });
+
+    test('should handle invalid hoursBetween gracefully', () => {
+      const medication = createMockMedication({
+        frequency: Frequency.EveryXHours,
+        hoursBetween: 0,
+      });
+
+      const schedule = generateSchedule([medication], baseDate);
+      expect(schedule).toEqual([]);
+    });
+  });
+
+  describe('generateReminderSchedule', () => {
+    const createMockReminder = (
+      overrides: Partial<CustomReminder> = {}
+    ): CustomReminder => ({
+      _id: 'reminder-1',
+      _rev: 'rev-1',
+      title: 'Test Reminder',
+      icon: '💊',
+      startTime: '09:00',
+      endTime: '17:00',
+      frequencyMinutes: 60,
+      ...overrides,
+    });
+
+    test('should return empty array for empty reminders', () => {
+      const schedule = generateReminderSchedule([], baseDate);
+      expect(schedule).toEqual([]);
+    });
+
+    test('should generate reminders within time window', () => {
+      const reminder = createMockReminder({
+        startTime: '10:00',
+        endTime: '12:00',
+        frequencyMinutes: 60,
+      });
+
+      const schedule = generateReminderSchedule([reminder], baseDate);
+
+      expect(schedule.length).toBeGreaterThan(0);
+      schedule.forEach(instance => {
+        expect(instance.reminderId).toBe('reminder-1');
+        expect(instance.title).toBe('Test Reminder');
+        expect(instance.icon).toBe('💊');
+        expect(instance.scheduledTime).toBeInstanceOf(Date);
+      });
+    });
+
+    test('should handle single time window', () => {
+      const reminder = createMockReminder({
+        startTime: '15:00',
+        endTime: '15:00',
+        frequencyMinutes: 60,
+      });
+
+      const schedule = generateReminderSchedule([reminder], baseDate);
+
+      expect(schedule).toHaveLength(1);
+    });
+
+    test('should sort reminders by time', () => {
+      const reminders = [
+        createMockReminder({
+          _id: 'reminder-1',
+          startTime: '18:00',
+          endTime: '18:00',
+        }),
+        createMockReminder({
+          _id: 'reminder-2',
+          startTime: '08:00',
+          endTime: '08:00',
+        }),
+      ];
+
+      const schedule = generateReminderSchedule(reminders, baseDate);
+
+      expect(schedule).toHaveLength(2);
+      // Should be sorted by time
+      expect(schedule[0].scheduledTime.getTime()).toBeLessThanOrEqual(
+        schedule[1].scheduledTime.getTime()
+      );
+    });
+
+    test('should generate unique IDs', () => {
+      const reminder = createMockReminder({
+        startTime: '10:00',
+        endTime: '11:00',
+        frequencyMinutes: 30,
+      });
+
+      const schedule = generateReminderSchedule([reminder], baseDate);
+
+      const ids = schedule.map(s => s.id);
+      const uniqueIds = new Set(ids);
+      expect(uniqueIds.size).toBe(ids.length);
+    });
+  });
+
+  describe('error handling', () => {
+    test('should handle malformed time strings', () => {
+      const medication: Medication = {
+        _id: 'bad-med',
+        _rev: 'rev-1',
+        name: 'Bad Med',
+        dosage: '10mg',
+        frequency: Frequency.Daily,
+        startTime: 'invalid:time',
+        notes: '',
+      };
+
+      // This will throw because the time parsing creates an invalid date
+      expect(() => generateSchedule([medication], baseDate)).toThrow();
+    });
+
+    test('should handle large frequency values', () => {
+      const medication: Medication = {
+        _id: 'large-med',
+        _rev: 'rev-1',
+        name: 'Large Med',
+        dosage: '10mg',
+        frequency: Frequency.EveryXHours,
+        startTime: '08:00',
+        hoursBetween: 100,
+        notes: '',
+      };
+
+      const schedule = generateSchedule([medication], baseDate);
+      expect(schedule.length).toBeLessThan(100);
+    });
+  });
+});