fix(#338): Add tests verifying WebSocket timer cleanup on error

- Add test for clearTimeout when workspace membership query throws
- Add test for clearTimeout on successful connection
- Verify timer leak prevention in catch block

Refs #338

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api/src/websocket/websocket.gateway.spec.ts

@@ -124,6 +124,52 @@ describe("WebSocketGateway", () => {
       expect(mockClient.disconnect).toHaveBeenCalled();
     });
 
+    it("should clear timeout when workspace membership query throws error", async () => {
+      const clearTimeoutSpy = vi.spyOn(global, "clearTimeout");
+
+      const mockSessionData = {
+        user: { id: "user-123", email: "test@example.com" },
+        session: { id: "session-123" },
+      };
+
+      vi.spyOn(authService, "verifySession").mockResolvedValue(mockSessionData);
+      vi.spyOn(prismaService.workspaceMember, "findFirst").mockRejectedValue(
+        new Error("Database connection failed")
+      );
+
+      await gateway.handleConnection(mockClient);
+
+      // Verify clearTimeout was called (timer cleanup on error)
+      expect(clearTimeoutSpy).toHaveBeenCalled();
+      expect(mockClient.disconnect).toHaveBeenCalled();
+
+      clearTimeoutSpy.mockRestore();
+    });
+
+    it("should clear timeout on successful connection", async () => {
+      const clearTimeoutSpy = vi.spyOn(global, "clearTimeout");
+
+      const mockSessionData = {
+        user: { id: "user-123", email: "test@example.com" },
+        session: { id: "session-123" },
+      };
+
+      vi.spyOn(authService, "verifySession").mockResolvedValue(mockSessionData);
+      vi.spyOn(prismaService.workspaceMember, "findFirst").mockResolvedValue({
+        userId: "user-123",
+        workspaceId: "workspace-456",
+        role: "MEMBER",
+      } as never);
+
+      await gateway.handleConnection(mockClient);
+
+      // Verify clearTimeout was called (timer cleanup on success)
+      expect(clearTimeoutSpy).toHaveBeenCalled();
+      expect(mockClient.disconnect).not.toHaveBeenCalled();
+
+      clearTimeoutSpy.mockRestore();
+    });
+
     it("should have connection timeout mechanism in place", () => {
       // This test verifies that the gateway has a CONNECTION_TIMEOUT_MS constant
       // The actual timeout is tested indirectly through authentication failure tests