Unit Testing - HttpSimulator

Have you ever wondered how to simulate HttpContext so that you can write your unit tests? TypeMock can do that but it's not a free tool.

HttpSimulator is a component composed of 2 classes; I am not sure whether Phil Haak has written it himself but it solves that problem nicely. You can download it from the bottom of this post.

Code sample:

Test:

public static HttpSimulator CreateHttpSimulator()
{
    return new HttpSimulator("/", @"c:\inetpub\").SimulateRequest();
}

[TestMethod()]
public void SetSessionTest()
{
    using (Helper.CreateHttpSimulator())
    {       
        // setup        
        var expectedValue = 2;      
        // exercise        
        Utils.SetSession(SessionKey.Basket, expectedValue);      
        // verify        
        var actualValue = Utils.GetFromSession(SessionKey.Basket);
        Assert.AreEqual(expectedValue, actualValue);  
       }
}

System Under Test:

public static void SetSession(SessionKey key, object value)
{
    HttpContext.Current.Session[key.ToString()] = value;
}

public static object GetFromSession(SessionKey key)
{
    if (HttpContext.Current == null  HttpContext.Current.Session == null)
        throw new ApplicationException("HttpContext.Current.Session is null");

    if (HttpContext.Current.Session[key.ToString()] == null)
        return null;

    return HttpContext.Current.Session[key.ToString()];
}