feat: add Jest testing framework and implement unit tests for configuration and service logic

tests/uptime-kuma.service.test.ts

@@ -0,0 +1,76 @@
+import { UptimeKumaService } from '../src/services/uptime-kuma.service';
+
+// Mock socket.io-client
+jest.mock('socket.io-client', () => ({
+  io: jest.fn().mockImplementation(() => ({
+    connected: false,
+    connect: jest.fn(),
+    disconnect: jest.fn(),
+    on: jest.fn(),
+    emit: jest.fn(),
+  })),
+}));
+
+// Mock other dependencies
+jest.mock('../src/config/config');
+jest.mock('../src/utils/logger');
+
+describe('UptimeKumaService', () => {
+  let uptimeKumaService: UptimeKumaService;
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    uptimeKumaService = new UptimeKumaService();
+  });
+
+  test('should create service instance', () => {
+    expect(uptimeKumaService).toBeDefined();
+  });
+
+  test('should return connection status', () => {
+    // Initially should be disconnected
+    expect(uptimeKumaService.isConnected()).toBe(false);
+  });
+
+  test('should handle connection state changes', () => {
+    // Mock socket connection
+    const mockSocket = {
+      connected: true,
+      connect: jest.fn(),
+      disconnect: jest.fn(),
+      on: jest.fn(),
+      emit: jest.fn(),
+    };
+
+    // Simulate connection by mocking the socket property and authentication
+    (uptimeKumaService as any).socket = mockSocket;
+    (uptimeKumaService as any).isAuthenticated = true;
+
+    expect(uptimeKumaService.isConnected()).toBe(true);
+
+    // Simulate disconnection
+    mockSocket.connected = false;
+    expect(uptimeKumaService.isConnected()).toBe(false);
+  });
+
+  test('should handle force reconnect', async () => {
+    // Mock the connect method to avoid socket.once issues
+    const mockConnect = jest.fn().mockResolvedValue(undefined);
+    (uptimeKumaService as any).connect = mockConnect;
+    
+    // Should not throw error even when not connected
+    await expect(uptimeKumaService.forceReconnect()).resolves.not.toThrow();
+    expect(mockConnect).toHaveBeenCalled();
+  });
+
+  test('should handle disconnect', () => {
+    // Should not throw error
+    expect(() => uptimeKumaService.disconnect()).not.toThrow();
+  });
+
+  test('should get monitor stats', () => {
+    const stats = uptimeKumaService.getMonitorStats();
+    expect(stats).toBeDefined();
+    expect(Array.isArray(stats)).toBe(true);
+  });
+});