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In this post , I will cover a test code that will mock the various elements needed to complete a HTTP page request and  assert the expected page cycle steps. To begin, i have a simple enumeration that has my predefined page steps:

  1. public enum PageStep
  2. {
  3.     PreInit,
  4.     Load,
  5.     PreRender,
  6.     UnLoad
  7. }

Once doing so, i  first created the page object [not mocking].

  1. Page page = new Page();

Here, our target is to fire up the page process through ProcessRequest call, now if we take a look inside the method with reflector.net,  the call trace will go like : ProcessRequest –> ProcessRequestWithNoAssert –> SetInstrinsics –> Finallly ProcessRequest. Inside SetInstrinsics ,  it requires calls from HttpRequest, HttpResponse and HttpBrowserCababilities. Using this clue at hand, we can easily know the classes / calls  we need to mock in order to get through the expected call.

Accordingly, for  HttpBrowserCapabilities our required mock code will look like:

  1. var browser = Mock.Create<HttpBrowserCapabilities>();
  2. // Arrange
  3. Mock.Arrange(() => browser.PreferredRenderingMime).Returns("text/html");
  4. Mock.Arrange(() => browser.PreferredResponseEncoding).Returns("UTF-8");
  5. Mock.Arrange(() => browser.PreferredRequestEncoding).Returns("UTF-8");

Now, HttpBrowserCapabilities is get through [Instance]HttpRequest.Browser. Therefore, we create the HttpRequest mock:

  1. var request = Mock.Create<HttpRequest>();

Then , add the required get call :

  1. Mock.Arrange(() => request.Browser).Returns(browser);

As, [instance]Browser.PerferrredResponseEncoding and [instance]Browser.PreferredResponseEncoding  are also set to the request object and to make that they are set properly, we can add the following lines as well [not required though].

  1. bool requestContentEncodingSet = false;
  2. Mock.ArrangeSet(() => request.ContentEncoding = Encoding.GetEncoding("UTF-8")).DoInstead(() =>  requestContentEncodingSet = true);

Similarly, for response we can write:

  1.  var response = Mock.Create<HttpResponse>();
  2.  
  3.  bool responseContentEncodingSet = false;
  4.  Mock.ArrangeSet(() => response.ContentEncoding = Encoding.GetEncoding("UTF-8")).DoInstead(() => responseContentEncodingSet = true);

Finally , I created a mock of HttpContext and set the Request and Response properties that will returns the mocked version.

  1. var context = Mock.Create<HttpContext>();
  2.  
  3. Mock.Arrange(() => context.Request).Returns(request);
  4. Mock.Arrange(() => context.Response).Returns(response);

As, Page internally calls RenderControl method , we just need to replace that with our one and optionally we can check if  invoked properly:

  1. bool rendered = false;
  2. Mock.Arrange(() => page.RenderControl(Arg.Any<HtmlTextWriter>())).DoInstead(() => rendered = true);

That’s  it, the rest of the code is simple,  where  i asserted the page cycle with the PageSteps that i defined earlier:

  1. var pageSteps = new Queue<PageStep>();
  2.  
  3. page.PreInit +=delegate { pageSteps.Enqueue(PageStep.PreInit); };
  4. page.Load += delegate { pageSteps.Enqueue(PageStep.Load); };
  5. page.PreRender += delegate { pageSteps.Enqueue(PageStep.PreRender);};
  6. page.Unload +=delegate { pageSteps.Enqueue(PageStep.UnLoad);};
  7.  
  8. page.ProcessRequest(context);
  9.  
  10. Assert.True(requestContentEncodingSet);
  11. Assert.True(responseContentEncodingSet);
  12. Assert.True(rendered);
  13.  
  14. Assert.Equal(pageSteps.Dequeue(), PageStep.PreInit);
  15. Assert.Equal(pageSteps.Dequeue(), PageStep.Load);
  16. Assert.Equal(pageSteps.Dequeue(), PageStep.PreRender);
  17. Assert.Equal(pageSteps.Dequeue(), PageStep.UnLoad);
  18.  
  19. Mock.Assert(request);
  20. Mock.Assert(response);

You can get the test class shown in this post here to give a try by yourself with of course JustMock :-).

Enjoy!!


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