依赖于HttpContext的单元测试

Question

I need to test some static methods that rely on the current context. Now, I can certainly use the HttpContextWrapper to remove this dependency from my own code. The problem lies with the 3rd party API I am using in these methods. THEY are relying on the HttpContext and so I can't do anything about that. However, what I'm trying to do is set the HttpContext with my HttpContextBase .

So my code looks something like this:

public static bool IsSignedUpUser()
{
    //This calls IsSignedUpUser with the production context
    return IsSignedUpUser(new HttpContextWrapper(HttpContext.Current));
}

public static bool IsSignedUpUser(HttpContextBase context)
{
    HttpCookie objCookie = SomeExternalAPIThatReliesOnHttpContextBeingSet();

    return (objCookie != null)
}

What I want to do is something like:

HttpContext.Current = context; //where context is a mocked HttpContextBase

This way when the 3rd party API is looking in the HttpContext for querystring, cookie values, etc, it doesn't throw a NullReferenceException .

Why isn't this a dupe?

In the code in the question referenced as a dupe, the author looks to be in complete control with no external dependencies. I'm using third party libraries that have a dependency on HttpContext , I can't change their method signatures to accept HttpContextBase so I need a way to assign my HttpContextBase to HttpContext .

If this is not possible, and so far I am lead to believe that it isn't, then good answers should suggest how to remove these dependencies. 500 - Internal Server Error has at least one good suggestion.

Answer 1

在我看来，您应该使用注入的自定义接口方法替换对SomeExternalAPIThatReliesOnHttpContextBeingSet的调用，然后可以像其他任何方法一样对其进行模拟。

Answer 2

[EDIT] Per @jessehouwing, "Moles" is now "Fakes", which should improve your Google-fu

Ah, static dependencies...the worse kind.

It may be overkill, but I would look into perhaps using Moles (or whatever the heck they renamed it to), which will let you override ANY behavior, static, sealed or otherwise; here are some links to peruse:

• Mocking the Unmockable
• The Moles Framework
• Unit Testing with Moles
• A different "Mocking the Unmockable"