public void Get_Random_WhenCalled_ReturnsOkResult() { // Arrange var expected = new Greeting { Id = Guid.NewGuid(), Name = "Hello ESDC", Message = "Test 1", }; this.mockGreetingService.Setup(x => x.GetRandom()).Returns(() => expected); // Act var controller = new GreetingController(this.mockGreetingService.Object); var result = controller.Random().Result; // Assert var okResult = result.Should().BeOfType <OkObjectResult>().Subject; var greeting = okResult.Value.Should().BeAssignableTo <Greeting>().Subject; greeting.Id.Should().Be(expected.Id); greeting.Name.Should().Be("Hello ESDC"); }