public void ExistsReturnsCorrectly() { //Arrange string name = "department name"; int hospitalId = 1; var departments = new List <Department> { new Department { HospitalId = hospitalId, Name = name }, new Department { HospitalId = hospitalId + 1, Name = name }, new Department { HospitalId = hospitalId, Name = $"{name}aaa" } }; var dbSet = departments.AsQueryable().BuildMockDbSet(); context.Setup(c => c.Set <Department>()).Returns(dbSet.Object); IDepartmentRepository repository = new DepartmentRepository(context.Object); //Act var result = repository.Exists(new Department { HospitalId = hospitalId, Name = name }).Result; //Assert Assert.IsInstanceOfType(result, typeof(Department)); Assert.AreEqual(name, result.Name); Assert.AreEqual(hospitalId, result.HospitalId); }