如何对用 ServiceFilterAttribute 自定义 ActionFilter 实现装饰的控制器进行单元测试

Question

总结:

我正在尝试使用 ActionFilter 实现

控制器

单元测试失败，因为在单元测试中没有调用 ActionFilter。
通过 Postman 进行的测试按预期工作并获得了正确的结果。
控制器可以这样测试还是应该进行集成测试？

细分:

我能够在单元测试中单独测试 ActionFilter，我想做的是在单元测试中测试控制器。

操作过滤器如下所示：

 public class ValidateEntityExistAttribute<T> : IActionFilter
        where T : class, IEntityBase
    {
        readonly AppDbContext _appDbContext;
        public ValidateEntityExistAttribute(AppDbContext appDbContext)
        {
            this._appDbContext = appDbContext;
        }

        public void OnActionExecuted(ActionExecutedContext context)
        {}

        public void OnActionExecuting(ActionExecutingContext context)
        {
            if (!context.ActionArguments.ContainsKey("id"))
            {
                context.Result = new BadRequestObjectResult("The id must be passed as parameter");
                return;
            }

            int id = (int)context.ActionArguments["id"];

            var foundEntity = _appDbContext.Set<T>().Find(id);
            if (foundEntity == null)
                context.Result = new NotFoundResult();
            else
                context.HttpContext.Items.Add("entity_found", foundEntity);
        }
    }

ActionFilter 实现添加到启动文件中的服务

ConfigureServices(IServiceCollection services)
{
...
 services.AddScoped<ValidateEntityExistAttribute<Meeting>>();
...
}

过滤器可以应用于任何需要检查实体是否存在的控制器方法。即 GetById 方法。

[HttpGet("{id}")]
[ServiceFilter(typeof(ValidateEntityExistAttribute<Meeting>))]
public async Task<ActionResult<MeetingDto>> GetById(int id)
    {            
        var entity = HttpContext.Items["entity_found"] as Meeting;
        await Task.CompletedTask;
        return Ok(entity.ConvertTo<MeetingDto>());
    }

在 xUnit 测试中，我设置了这样的测试来测试控制器：

[Fact]
public async Task Get_Meeting_Record_By_Id()
{
    // Arrange
    var _AppDbContext = AppDbContextMocker.GetAppDbContext(nameof(Get_All_Meeting_Records));
    var _controller = InitializeController(_AppDbContext);

    //Act
    
    var all = await _controller.GetById(1);

    //Assert
    Assert.Equal(1, all.Value.Id);

    //clean up otherwise the other test will complain about key tracking.
    await _AppDbContext.DisposeAsync();
}

这就是 InitializeController 方法的样子，我留下了注释行，以便它对我尝试的内容可见，none 注释代码有效。我嘲笑并使用默认类.

private MeetingController InitializeController(AppDbContext appDbContext)
    {

        var _controller = new MeetingController(appDbContext);

        var spf = new DefaultServiceProviderFactory(new ServiceProviderOptions { ValidateOnBuild = true, ValidateScopes = true });
        var sc = spf.CreateBuilder(new ServiceCollection());

        sc.AddMvc();
        sc.AddControllers();
        //(config =>
        //{
        //    config.Filters.Add(new ValidateModelStateAttribute());
        //    config.Filters.Add(new ValidateEntityExistAttribute<Meeting>(appDbContext));
        //});
        
        sc.AddTransient<ValidateModelStateAttribute>();
        sc.AddTransient<ValidateEntityExistAttribute<Meeting>>();

        var sp = sc.BuildServiceProvider();

        //var mockHttpContext = new Mock<HttpContext>();
        var httpContext = new DefaultHttpContext
        {
            RequestServices = sp
        };
        //mockHttpContext.Setup(cx => cx.RequestServices).Returns(sp);

        //var contDesc = new ControllerActionDescriptor();
        //var context = new ControllerContext();
        //var context = new ControllerContext(new ActionContext(mockHttpContext.Object, new RouteData(), contDesc));

        //context.HttpContext = mockHttpContext.Object;
        //context.HttpContext = httpContext;
        //_controller.ControllerContext = context;
        _controller.ControllerContext.HttpContext = httpContext;

        return _controller;
    }

我遇到的问题是当运行单元测试时从未调用ActionFilter实现，因此破坏了测试，因为var entity = HttpContext.Items["entity_found"] as Meeting;在控制器中总是 null！更准确地说 HttpContext.Items 总是空的。

永远不会命中 ActionFilter 中的断点。

当通过邮递员进行测试时，一切都按预期工作，并且遇到了断点

有没有办法以这种方式将控制器作为单元测试进行测试，或者现在应该将此测试转移到集成？

Answer 1

感谢@Fei Han link about unit testing controllers.

事实证明这是设计使然，如 Microsoft 文档中所述

Unit testing controllers Set up unit tests of controller actions to focus on the controller's behavior. A controller unit test avoids scenarios such as filters, routing, and model binding. Tests that cover the interactions among components that collectively respond to a request are handled by integration tests.

所以测试应该转到集成测试。

在这个特定场景中，GetById(int id)方法没有详细的实现，单元测试几乎没有价值 为之。

如果 GetById(int id) 方法有更复杂的实现，或者如果 ActionFilter 没有阻止进一步的处理，那么 HttpContext.Items["entity_found"] 应该被模拟。

如何对用 ServiceFilterAttribute 自定义 ActionFilter 实现装饰的控制器进行单元测试

How do I unit test a controller that is decorated with the ServiceFilterAttribute, custom ActionFilter implementation

c#

unit-testing

asp.net-core

.net-core

custom-action-filter