getOfferings unit test

Author: thomasyzy7

course-matrix/backend/__tests__/unit-tests/getOfferings.test.ts

@@ -0,0 +1,60 @@
+import {describe, expect, it, jest, test} from '@jest/globals';
+
+import {supabase} from '../../src/db/setupDb';
+import getOfferings from '../../src/services/getOfferings';
+
+jest.mock('../../src/db/setupDb', () => ({
+                                    supabase: {
+                                      schema: jest.fn(),
+                                    },
+                                  }));
+
+type SupabaseQueryResult = Promise<{data: any; error: any;}>;
+
+describe('getOfferings', () => {
+  it('returns offering data for a valid course and semester', async () => {
+    const mockData = [
+      {
+        id: 1,
+        course_id: 123,
+        meeting_section: 'L01',
+        offering: 'Fall 2025',
+        day: 'Mon',
+        start: '10:00',
+        end: '11:00',
+        location: 'Room 101',
+        current: 30,
+        max: 40,
+        is_waitlisted: false,
+        delivery_mode: 'In-Person',
+        instructor: 'Dr. Smith',
+        notes: '',
+        code: 'ABC123',
+      },
+    ];
+
+    // Build the method chain mock
+    const eqMock2 = jest.fn<() => SupabaseQueryResult>().mockResolvedValue({
+      data: mockData,
+      error: null,
+    });
+    const eqMock1 = jest.fn(() => ({eq: eqMock2}));
+    const selectMock = jest.fn(() => ({eq: eqMock1}));
+    const fromMock = jest.fn(() => ({select: selectMock}));
+    const schemaMock = jest.fn(() => ({from: fromMock}));
+
+    // Replace supabase.schema with our chain
+    (supabase.schema as jest.Mock).mockImplementation(schemaMock);
+
+    // Act
+    const result = await getOfferings(123, 'Fall 2025');
+
+    // Assert
+    expect(schemaMock).toHaveBeenCalledWith('course');
+    expect(fromMock).toHaveBeenCalledWith('offerings');
+    expect(selectMock).toHaveBeenCalled();
+    expect(eqMock1).toHaveBeenCalledWith('course_id', 123);
+    expect(eqMock2).toHaveBeenCalledWith('offering', 'Fall 2025');
+    expect(result).toEqual(mockData);
+  });
+});