How do you test your Request.QueryString[] variables?

Question

I frequently make use of Request.QueryString[] variables.

In my Page_load I often do things like:

       int id = -1;

             


        

Answer 1

Eeee this is a karma risk...

I have a DRY unit-testable abstraction because, well, because there were too many querystring variables to keep on in a legacy conversion.

The code below is from a utility class whose constructor requires a NameValueCollection input (this.source) and the string array "keys" is because the legacy app was rather organic and had developed the possibility for several different strings to be a potential input key. However I kind of like the extensibility. This method inspects the collection for the key and returns it in the datatype required.

private T GetValue(string[] keys)
{
    return GetValue(keys, default(T));
}

private T GetValue(string[] keys, T vDefault)
{
    T x = vDefault;

    string v = null;

    for (int i = 0; i < keys.Length && String.IsNullOrEmpty(v); i++)
    {
        v = this.source[keys[i]];
    }

    if (!String.IsNullOrEmpty(v))
    {
        try
        {
            x = (typeof(T).IsSubclassOf(typeof(Enum))) ? (T)Enum.Parse(typeof(T), v) : (T)Convert.ChangeType(v, typeof(T));
        }
        catch(Exception e)
        {
            //do whatever you want here
        }
    }

    return x;
}