I have an action that returns either a FileContentResult or a NotModifiedResult, which is a custom result type that returns HTTP 304 to indicate that the requested resource has not been modified, like this:
[ReplaceMissingPicture(Picture = "~/Content/Images/nothumbnail.png", MimeType = "image/png")]
public ActionResult Thumbnail(int id)
{
var item = Service.GetItem(id);
var requestTag = Request.Headers["If-None-Match"] ?? string.Empty;
var tag = Convert.ToBase64String(item.Version.ToArray());
if (tag == requestTag)
{
return new NotModifiedResult();
}
if (item.Thumbnail != null)
{
var thumbnail = item.Thumbnail.ToArray();
var mime = item.PictureMime;
Response.AppendHeader("ETag", tag);
return File(thumbnail, mime);
}
else
{
return null;
}
}
This action needs to access the Response object, which is of course not present during testing, so that makes this action untestable. I could add conditional statements around it, so that it runs during testing, but then I can't test for the headers being set correctly.
What would be a solution to this problem?
FYI, the ReplaceMissingPicture filter returns a specific resource in case null was returned from this action, to keep the MapPath() call out of the controller for the very same reason.
The first step would be to create an interface which simplifies the services you need:-
public interface IHeaders
{
public string GetRequestHeader(string headerName);
public void AppendResponseHeader(string headerName, string headerValue);
}
Now create a default implementation:-
public Headers : IHeaders
{
public string GetRequestHeader(string headerName)
{
return HttpContext.Current.Request[headerName];
}
public void AppendResponseHeader(string headerName, string headerValue)
{
HttpContext.Current.Response.AppendHeader(headerName, headerValue);
}
}
Now add a new field to your Controller:-
private IHeaders myHeadersService;
add new constructor to you controller:-
public MyController(IHeaders headersService)
{
myHeadersService = headersService;
}
modify or add the default constructor:-
public MyController()
{
myHeadersService = new Headers();
}
now in your Action code use myHeadersService instead of the Response and Request objects.
In your tests create your own implementation of the IHeaders interface to emulate/test the Action code and pass that implementation when constructing the Controller.
How about creating a subclass of FileResult--say ETagFileResult--that in its ExecuteResult() method sets the ETag header, and then defaults to the base class implementation? You can test that class with a mocked context (as you presumably are with your NotModifiedResult) to be sure that it's doing the right thing. And remove the entire complication from the testing of the controller.
Failing that, it's possible to set a mocked context on the controller in your test (after instantiating the class, before calling the action method). See this question, for instance. But that seems like more work.
(Also, by the way, it looks like you're quoting the tag value twice there: once when tag is set, and once more when you actually set the header....)
Related
In ASP.Net Web API, the action returned object will be converted to XML or JSON automatically - is there a way to add additional process to the returned object before it gets converted?
What I want to achieve is to wrap returned object into a generic APIResponse (another class) type which has an object Property called Data that will be assigned with whatever the original returned object is.
for example:
public Books[] FindBooks(string keyword)
{
..
return new Books[] {new Book(){Name="ASP.NET"}};
}
This will return JSON of book array by default, however I want to wrap the result into an object called APIResponse, so the returned object becomes:
new APIResponse(){
Data = //the Book[] array return from the action method
}
By doing this, I will be able to keep the freedom of returning normal business objects in Web API however always return the same object type in JSON format when the front-end Ajax requests.
I believe it can be done in a way however I'm not familiar with the Web API life cycle, can any way give some guide on this?
Thank you.
I fixed it by creating a custom MediaTypeFormatter however simply inheriting from JSON formatter which have already got all what I need, here is the very simple code I added, which resolved all issues I have!!!
public class APIResponseMediaFomatter : JsonMediaTypeFormatter
{
public override Task WriteToStreamAsync(Type type, object value, System.IO.Stream writeStream, System.Net.Http.HttpContent content, System.Net.TransportContext transportContext)
{
ResponseMessage wrappedValue = null;
if (type != typeof(ResponseMessage) || (value != null && value.GetType() != typeof(ResponseMessage)))
wrappedValue = new ResponseMessage(value);
return base.WriteToStreamAsync(typeof(ResponseMessage), wrappedValue, writeStream, content, transportContext);
}
}
Cheers!
Interestingly, Web API already works exactly how you describe. It already has generic request and response classes that can hold your object payload. Just do the following,
public HttpResponseMessage FindBooks(string keyword)
{
...
var books = new Books[] {new Book(){Name="ASP.NET"}};
var content = new ObjectContent<Book[]>(books,new JsonMediaTypeFormatter());
return new HttpResponseMessage { Content = content);
}
There is no need to re-invent your own generic response object that can hold metadata and data, HTTP has already done that for you.
Why dont you return your wrapper object APIResponse from WebAPI
public APIResponse FindBooks(string keyword)
{
var books = new Books[] {new Book(){Name="ASP.NET"}};
return new APIResponse {Data= books };
}
Just use an action filter, and modify the response content inside it:
public class ApiResponseWrapperActionFilter : ActionFilterAttribute
{
public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
{
// Check that the response is an object content
var objectContent = actionExecutedContext.Response.Content as ObjectContent;
if (objectContent != null)
{
// Wrap the returned value in the ApiResponse
objectContent.Value = new ApiResponse() { Data = objectContent.Value };
}
}
Apply the filter to the whole API (in global config) or a whole controller (attribute applied to the controller class) or to the desired methods (attribute in each method).
If you're returning something that it's not an object (a custom response) it will skip the wrapping.
I am using MVC3, .NET4, C#.
I need to create some XHTML using a Razor View. I do this via an Action.
public ActionResult RenderDoc(int ReportId)
{
//A new document is created.
return View();
}
I then need to take the output from this and convert it to a Word Doc. I am using a 3rd party component to do this and it expects a "stream" or a "file" for the XHTML source that is read in for conversion to a DOC, like the following:
document.Open(MyXhtmlStream,FormatType.Html,XHTMLValidationType.Transitional);
My Question:
What would be a good way to call the "RenderDoc" Action and obtain the result as a stream to feed into "MyXhtmlStream".
Many thanks.
EDIT: I have had another idea !!!
1) Render the View within the action to create a String(XHTMLString). I have seen a method to do this on SO.
2) Create a MemoryStream and put this string into it.
Stream MyStream = New MemoryStream("XHTMLString and encoding method");
EDIT2: Based on Darin's answer
I need to clasyify a little further, and I hope to do this via tweaking Darin's code for my purpose.
public class XmlDocumentResult : ActionResult
{
private readonly string strXhtmlDocument;
public XmlDocumentResult(string strXhtmlDocument)
{
this.strXhtmlDocument = strXhtmlDocument;
}
public override void ExecuteResult(ControllerContext context)
{
WordDocument myWordDocument = new WordDocument();
var response = context.HttpContext.Response;
response.ContentType = "text/xml";
myWordDocument.Open(response.OutputStream, FormatType.Html, XHTMLValidationType.Transitional);
}
}
The above is closer to what I need. Note the 3rd Party WordDocument type. So there is still the issue of how I get the "strXhtmlDocument" into the "Response.OutputStream?
I would just write a custom ActionResult to handle that:
public class XmlDocumentResult : ActionResult
{
private readonly Document document;
public XmlDocumentResult(Document document)
{
this.document = document;
}
public override void ExecuteResult(ControllerContext context)
{
var response = context.HttpContext.Response;
response.ContentType = "text/xml";
document.Open(response.OutputStream, FormatType.Html, XHTMLValidationType.Transitional);
}
}
You could of course adjust the response Content-Type if necessary and also append a Content-Disposition header if you want.
And then simply have my controller action return this custom action result:
public ActionResult RenderDoc(int reportId)
{
Document document = repository.GetDocument(reportId);
return new XmlDocumentResult(document);
}
Now the controller action doesn't need to handle plumbing code anymore. The controller action does what a typical controller action is supposed to do:
Query the Model
Pass this model to an ActionResult
In your case the model is this Document class or whatever it is called.
I am new to nSubstitute. And I am writing test method for my controller class. I have a TestMethod called GetDefaultStateTest() which having Substitute class as shown below
[TestMethod]
public void GetDefaultStateTest()
{
var _GetDefaultState = Substitute.For<CustomerController>(ICustomer cus);
Assert.IsNotNull(_GetDefaultState.GetDefaultState());
}
Because my controller class having parameterized constructor as below.
public class CustomerController : Controller
{
private readonly ICustomer _customer;
public CustomerController(ICustomer customer)
{
_customer = customer;
}
public string GetDefaultState()
{
// Get default state from settings table
List<tblSettings> settings = new List<tblSettings>();
// Calling service method GetSettings
settings = _customer.GetSettings();
var defaultState = from setting in settings
where setting.Desc == "DefaultState"
select setting.Settings;
string strState = "";
foreach (var oState in defaultState)
{
strState = oState;
break;
}
return strState;
}
}
While run the test method, it raise null reference issue. Because of parameter ICustomer is null
var _GetDefaultState = Substitute.For<CustomerController>(ICustomer cus);
How to resolve this problem.
If you are testing your controller class then you do not want to substitute for it, you want to use a real one (otherwise you'd just be testing a fake object "works" :)). Where you may want to substitute is for that class's dependencies, in this case, ICustomer.
[TestMethod]
public void GetDefaultStateTest()
{
var customer = Substitute.For<ICustomer>();
var controller = new CustomerController(customer);
Assert.IsNotNull(controller.GetDefaultState());
}
You may then want to fake out the ICustomer.GetSettings() method so you can test what your controller does with that data:
[TestMethod]
public void GetDefaultStateTestFromSettings()
{
var customer = Substitute.For<ICustomer>();
customer.GetSettings().Returns(somethingSensible);
var controller = new CustomerController(customer);
Assert.AreEqual(expectedDefaultState, controller.GetDefaultState());
}
As an aside, sometimes it makes more sense to use real objects (say, a real implementation of ICustomer) rather than substitutes. This will depend on how well-defined the interactions with the dependencies are, where you want to define the boundaries of your system under test, and how much confidence the test gives you that the system under test is working correctly. Or put more simply, whatever makes it easy and reliable to test. :)
Hope this helps.
I have a method which looks like the one below
public List<Rajnikanth> GetRajnis()
{
string username = Utility.Helpers.GetLoggedInUserName();
return _service.GetRajni(username);
}
Utility.Helper is a static class,
public static class Helpers
{
public static String GetLoggedInUserName()
{
string username = "";
if (System.Web.HttpContext.Current.User.Identity.IsAuthenticated)
{
username = ((System.Web.Security.FormsIdentity)HttpContext.Current.User.Identity).Ticket.Name;
}
return username;
}
}
I want to test : GetRajnis()
I want to mock : GetLoggedInUserName()
So my test method looks something like...
[TestMethod]
public void TestGetRajnis()
{
SomeController s = new SomeController(new SomeService());
var data = s.GetRajnis();
Assert.IsNotNull(data);
}
how do I mock the static method GetLoggedInUserName() ?
The Simplest Approach: Override the return value
If you are looking to mock a return value, then this is very simple. You can modify the Utility.Helper class to include a property called OverrideLoggedInUserName. When someone calls GetLogedInUserName(), if the override property is set, it is returned, otherwise the normal code to get the value from the HttpContext is used to get the return value.
public static class Helper
{
// Set this value to override the return value of GetLoggedInUserName().
public static string OverrideLoggedInUserName { get; set; };
public static string GetLoggedInUserName()
{
// Return mocked value if one is specified.
if ( !string.IsNullOrEmpty( OverrideLoggedInUserName ) )
return OverrideLoggedInUserName;
// Normal implementation.
string username = "";
if ( System.Web.HttpContext.Current.User.Identity.IsAuthenticated )
{
username = ( (System.Web.Security.FormsIdentity)HttpContext.Current.User.Identity ).Ticket.Name;
}
return username;
}
}
This will effectively allow you to override the return value, which technically isn't a mock--it's a stub (according to the excellent article Mocks Aren't Stubs by Martin Fowler). This allows you to stub a return value, but won't allow you to assert whether the method was called or not. Anyhow as long as you only want to manipulate the return value this works fine.
Here is how you would use this in a test.
[ TestMethod ]
public void TestGetRajnis()
{
// Set logged in user name to be "Bob".
Helper.OverrideLoggedInUserName = "Bob";
SomeController s = new SomeController( new SomeService() );
var data = s.GetRajnis();
// Any assertions...
}
This design does have one drawback. Because it's a static class, if you set the override value, it remains set until you un-set it. So you must remember to re-set it to null.
A Better Approach: Inject the dependency
A better approach may be to create a class that retrieves the logged in user name, and pass it into the constructor of SomeController. We call this dependency injection. This way, you can inject a mocked instance into it for testing, but pass the real instance (that gets the user from the HttpContext) when not testing. This is a much cleaner and clearer approach. Plus, you can leverage all the power of whatever mocking framework you are using, since they are designed specifically to handle this approach. Here is what that would look like.
// Define interface to get the logged in user name.
public interface ILoggedInUserInfo
{
string GetLoggedInUserName();
}
// Implementation that gets logged in user name from HttpContext.
// This class will be used in production code.
public class LoggedInUserInfo : ILoggedInUserInfo
{
public string GetLoggedInUserName()
{
// This is the same code you had in your example.
string username = "";
if ( System.Web.HttpContext.Current.User.Identity.IsAuthenticated )
{
username = ( (System.Web.Security.FormsIdentity)HttpContext.Current.User.Identity ).Ticket.Name;
}
return username;
}
}
// This controller uses the ILoggedInUserInfo interface
// to get the logged in user name.
public class SomeController
{
private SomeService _service;
private ILoggedInUserInfo _userInfo;
// Constructor allows you inject an object that tells it
// how to get the logged in user info.
public SomeController( SomeService service, ILoggedInUserInfo userInfo )
{
_service = service;
_userInfo = userInfo;
}
public List< Rajnikanth > GetRajnis()
{
// Use the injected object to get the logged in user name.
string username = _userInfo.GetLoggedInUserName();
return _service.GetRajni( username );
}
}
And here is a test using Rhino Mocks to inject a stub object into the controller.
[ TestMethod ]
public void TestGetRajnis()
{
// Create a stub that returns "Bob" as the current logged in user name.
// This code uses Rhino Mocks mocking framework...
var userInfo = MockRepository.GenerateStub< ILoggedInUserInfo >();
userInfo.Stub( x => x.GetLoggedInUserName() ).Return( "Bob" );
SomeController s = new SomeController( new SomeService(), userInfo );
var data = s.GetRajnis();
// Any assertions...
}
The disadvantage here is that you can't just call Helper.GetLoggedInUserName() from anywhere in your code, because it's no longer static. However, you no longer have the need to reset the stubbed username every time you finish a test. Because it's not static, it it automatically reset. You just recreate it for the next test and set a new return value.
I hope this helps.
Get rid of the static class if you are looking for testability. A simple fix for now would be to create a wrapper around the static class. Unless you use something like TypeMock or something equally as powerful, then you cannot alter the logic of a static class. Nor do I suggest it. If you have to stub a static class, it probably should not be a static class.
public class StaticWrapper
{
public virtual String GetLoggedInUserName()
{
Utility.Helpers.GetLoggedInUserName();
}
}
I'm trying to unit test a custom action result. I recently watched Jimmy Bogard's excellent MvcConf video ("put your controllers on a diet") http://www.viddler.com/explore/mvcconf/videos/1/ and have started to try and implement some custom action results. I've managed that without a problem, the ActionResult works fine at runtime but I'm having trouble trying to unit test them.
Unfortunately in the code download there are no unit tests for Jimmy's custom action methods... which make me wonder.
I realise that action methods just return instances of the ActionResult types and its the MVC framework that actually calls the ExecuteResult method, which of course is not available when running the unit test. So my unit test is now just creating an instance of my custom ActionResult and I then call ExecuteResult.
Unfortunatley in the ExecuteResult method of my custom ActionResult it is also calling the ExecuteResult method of a ViewResult that I passed it. At that point it blows up. How should I be mocking/stubbing these things to get my unit test working?
public class SendToAFriendActionResult : ActionResult
{
public const string INVALID_CAPTCHA = "You don't appear to have filled out the two words from the security image correctly to prove you're a human. Please try again.";
public const string INVALID_MODEL_STATE = "You don't appear to have filled out all the details correctly. Please try again.";
public const string CONTACT_FAIL = "Unfortunately we experiend a problem sending the link. Please try again later.";
public const string SEND_TO_A_FRIEND_FAIL_KEY = "ContactFail";
private RedirectResult _success;
private ViewResult _failure;
private readonly SendToAFriendModel _model;
private readonly bool _captchaValid;
private readonly MessageBuilderServiceBase _mbs;
public RedirectResult Success
{
get { return _success; }
set { _success = value; }
}
public ViewResult Failure
{
get { return _failure; }
set { _failure = value; }
}
public SendToAFriendActionResult(RedirectResult success, ViewResult failure, SendToAFriendModel model, bool captchaValid, MessageBuilderServiceBase mbs)
{
_success = success;
_failure = failure;
_model = model;
_captchaValid = captchaValid;
_mbs = mbs;
}
public override void ExecuteResult(ControllerContext context)
{
if (!_captchaValid)
{
Failure.TempData[SEND_TO_A_FRIEND_FAIL_KEY] = INVALID_CAPTCHA;
// On reaching this point I receive the error
// Object reference not set to an instance of an object
// as the MVC framework calls FindView
Failure.ExecuteResult(context);
return;
}
if (!context.Controller.ViewData.ModelState.IsValid)
{
Failure.TempData[SEND_TO_A_FRIEND_FAIL_KEY] = INVALID_MODEL_STATE;
Failure.ExecuteResult(context);
return;
}
_mbs.RecipientEmailAddress = _model.EmailRecipient;
_mbs.SendersName = _model.SendersName;
_mbs.Url = _model.URL;
var result = _mbs.sendMessage();
if (!result)
{
Failure.TempData[SEND_TO_A_FRIEND_FAIL_KEY] = CONTACT_FAIL;
Failure.ExecuteResult(context);
return;
}
Success.ExecuteResult(context);
}
}
Here's the start of my unit test ...
IMessageService _emailMessageSerivce;
IGalleryRepository _repository;
var stfModel = new SendToAFriendModel
{
SendersName = "Someone",
URL = "http://someurl.com",
EmailRecipient = "a-friend#somewherelse.com"
};
var failure = new ViewResult() {ViewName ="SendToFriend"};
const bool captchaValid = false;
var fakeControlllerContext = MockRepository.GenerateStub<ControllerContext>(null);
var stf = new SendToAFriendActionResult(null, failure, stfModel, captchaValid, null);
stf.ExecuteResult(fakeControlllerContext);
I've put comments in the SUT to show were the problem occurs.
I know I should be stubbing/mocking somehow but I just can't seem to resolve this.
From ASP.NET MVC 2 In Action (coauthored by Jimmy Bogard):
By taking that hard-to-test code out
of an action and putting it into the
Execute method of an action result,
you ensure that the actions become
significantly easier to unit-test.
That’s because when you unit-test an
action, you assert the type of action
result that the action returns and the
state of the action result. The
Execute method of the action result
isn’t executed as part of the unit
test.
Unit tests are designed to isolate behavior and concerns. You're mixing concerns by calling ExecuteResult from within your custom Action. Instead, I would have the SendToAFriendActionResult return the actual ActionResult (Failure or Success):
public ActionResult GetAction(..)
{
ActionResult result;
//logic here to determine which ActionResult to return
return result;
}
In your Controller:
public ViewResult SendToAFriend()
{
return SendToAFriendActionResult(null, failure, stfModel, captchaValid, null)
.GetAction();
}
This method will allow the MVC framework to do its job and isolates those concerns outside your custom ActionResult. Your test should assert that the correct type of Action, failure or success, is returned based on the parameters you set going in.