import { Test, TestingModule } from "@nestjs/testing"; import { DatabaseService } from "./database/database.service"; import { HealthController } from "./health.controller"; describe("HealthController", () => { let controller: HealthController; const mockDb = { execute: jest.fn().mockResolvedValue([]), }; beforeEach(async () => { const module: TestingModule = await Test.createTestingModule({ controllers: [HealthController], providers: [ { provide: DatabaseService, useValue: { db: mockDb, }, }, ], }).compile(); controller = module.get(HealthController); }); it("should return ok if database is connected", async () => { mockDb.execute.mockResolvedValue([]); const result = await controller.check(); expect(result.status).toBe("ok"); expect(result.database).toBe("connected"); }); it("should return error if database is disconnected", async () => { mockDb.execute.mockRejectedValue(new Error("DB Error")); const result = await controller.check(); expect(result.status).toBe("error"); expect(result.database).toBe("disconnected"); expect(result.message).toBe("DB Error"); }); });