add unit tests for fetchSupportFrontendData function

Author: AnastasiiaBalenko

src/server/utils/supportFrontend.test.ts

@@ -0,0 +1,43 @@
+import { fetchSupportFrontendData } from './supportFrontend';
+
+describe('fetchSupportFrontendData', () => {
+    const originalFetch = global.fetch;
+
+    beforeAll(() => {
+        global.fetch = jest.fn();
+    });
+
+    afterAll(() => {
+        global.fetch = originalFetch;
+    });
+    it('should throw an error if no endpoint is provided', async () => {
+        await expect(fetchSupportFrontendData('')).rejects.toThrow('No endpoint value supplied');
+    });
+    it('should throw an error if fetch response is not ok', async () => {
+        (global.fetch as jest.Mock).mockResolvedValueOnce({
+            ok: false,
+            status: 404,
+        });
+        await expect(fetchSupportFrontendData('test-endpoint')).rejects.toThrow(
+            'HTTP error! Status: 404',
+        );
+    });
+
+    it('should return response text if fetch is successful', async () => {
+        const mockText = 'response data';
+        (global.fetch as jest.Mock).mockResolvedValueOnce({
+            ok: true,
+            text: jest.fn().mockResolvedValueOnce(mockText),
+        });
+        const data = await fetchSupportFrontendData('test-endpoint');
+        expect(data).toBe(mockText);
+    });
+
+    it('should throw an error if fetch fails', async () => {
+        const mockError = new Error('Network error');
+        (global.fetch as jest.Mock).mockRejectedValueOnce(mockError);
+        await expect(fetchSupportFrontendData('test-endpoint')).rejects.toThrow(
+            'Data fetch error: Error: Network error',
+        );
+    });
+});