如何对 ActionFilterAttribute 进行单元测试

Question

我想在 .NET Core 2.0 API 项目中测试 ActionFilterAttribute 并想知道最好的方法。请注意，我并不是要通过控制器操作来测试它，而只是测试 ActionFilterAttribute 本身。

我该如何进行测试：

    public class ValidateModelAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext context)
        {
            if (!context.ModelState.IsValid)
            {
                context.Result = new BadRequestObjectResult(context.ModelState);
            }
        }
    }

Answer 1

创建上下文实例，将其传递给过滤器并断言预期行为

例如

[TestClass]
public class ValidateModelAttributeTest {
    [TestMethod]
    public void Invalid_ModelState_Should_Return_BadRequestObjectResult() {
        //Arrange
        var modelState = new ModelStateDictionary();
        modelState.AddModelError("", "error");
        var httpContext = new DefaultHttpContext();
        var context = new ActionExecutingContext(
            new ActionContext(
                httpContext: httpContext,
                routeData: new RouteData(),
                actionDescriptor: new ActionDescriptor(),
                modelState: modelState
            ),
            new List<IFilterMetadata>(),
            new Dictionary<string, object>(),
            new Mock<Controller>().Object);

        var sut = new ValidateModelAttribute();

        //Act
        sut.OnActionExecuting(context);

        //Assert
        context.Result.Should().NotBeNull()
            .And.BeOfType<BadRequestObjectResult>();
    }
}

Answer 2

这是一个真实的例子，我还访问了动作过滤器属性中的方法信息和参数：

假设我有一个带有 ActionAttribute 的控制器方法，如下所示：

 public class HomeController : Controller
    {
    ...
    [FeatureFlagActionAtrribute("user", new String[] { "Feature1" })]
    public IActionResult DoSomethingWithFilterAction(String user)
        {...}
    }

http 调用将是这样的：

/Home/DoSomethingWithFilterAction?user="user1"

现在，我想在这样的上下文中测试 ActionAttribute FeatureFlagActionAtrribute。

如果你将以上建议应用到这个例子中，它看起来像这样（至少对我有用）

 var methodInfoDoSomethingWithFilterAction = typeof(HomeController).GetMethod(nameof(HomeController.DoSomethingWithFilterAction));
    var httpContext = new DefaultHttpContext();
    var routeData = new RouteData();
    FeatureFlagActionAtrribute FeatureFlagActionAtrributeFilter = methodInfoDoSomethingWithFilterAction.GetCustomAttribute<FeatureFlagActionAtrribute>();
    ActionDescriptor actionDescriptor = new ControllerActionDescriptor()
                {
                    ActionName = methodInfoDoSomethingWithFilterAction.Name,
                    ControllerName = typeof(FeatureFlagTest).Name,
                    DisplayName = methodInfoDoSomethingWithFilterAction.Name,
                    MethodInfo = methodInfoDoSomethingWithFilterAction,
                };

    ActionContext actionContext = new ActionContext(httpContext, routeData, actionDescriptor) ;
    var homeController = new HomeController();
    var attribute = new FeatureFlagActionAtrribute("user", new string[] { "feature1" });
    IDictionary<string, object> actionArguments = new Dictionary<string, object>
                {
                    ["user"] = "user1"
                };

    var filterMetadata = new List<IFilterMetadata>() { featureFlagActionAtrributeFilter };

    ActionExecutingContext actionExecutedContext = new 
    ActionExecutingContext(actionContext, filterMetadata, actionArguments, homeController);


    attribute.OnActionExecuting(actionExecutedContext);

然后在ActionFilterAttribute里面：

public override void OnActionExecuting(ActionExecutingContext context)
{
        ControllerActionDescriptor actionDescriptor = (ControllerActionDescriptor)context.ActionDescriptor;
        Debug.Print($"2. @Before Method called {actionDescriptor.ControllerName}Controller.{actionDescriptor.ActionName}");
        var controllerName = actionDescriptor.ControllerName;
        var actionName = actionDescriptor.ActionName;
        IDictionary<object, object> properties = actionDescriptor.Properties;
        ParameterInfo[] paramsOfMethod = actionDescriptor.MethodInfo.GetParameters();
        var fullName = actionDescriptor.DisplayName;

        var paramNameForKeyOfFeature = ParamNameForKeyOfFeature;

        var arguments = context.ActionArguments;

如何对 ActionFilterAttribute 进行单元测试

How to unit test ActionFilterAttribute

unit-testing

xunit

xunit.net

actionfilterattribute

.net-core