Creating Proxy/Mock Object From/Of Generic Type

Question

I would like to implement the following method:

public static T CreateProxyObject<T>(Dictionary<String,Object> setup)

With the following Rules:

1) I want to stay as generic as possible means T is not known during compile time and I want to be able to return it to user as the mocked/proxy requested type (user can still use normal intellisense to get object's metadata).

2) It should have all its properties set/setup based on the setup Dictionary:

String-> property name of the object

Object-> the return value for this property

Any other method should be implemented with throwing not implemented exception

I was trying to use mock of T (from Moq framework) but T must be reference type.

Had no success as well with Castle DynamicProxy and RealProxy.

Any Idea?

score 1 · Answer 1 · answered Jun 11 '17 at 20:41

1

Try castle dictionary adapter http://kozmic.net/2014/03/22/strongly-typed-app-settings-with-castle-dictionaryadapter/

answered Jun 11 '17 at 20:41

Yaser Moradi

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It still leaves me with a problem when the interface has methods: the following code fails on the CreateProxyObject method(creating the adapter) : https://gist.github.com/countoren/013bdbef42891ec21dd61692aa652f7e – CountOren Jun 12 '17 at 03:23

score 0 · Accepted Answer · answered Jun 13 '17 at 18:50

After searching a bit more I found this answer that guided me to use impromptu-interface which uses expandoobject/dynamic object in order to implement an interface, And together with this answer (which solve the problem of setting the properties dynamically),

I was able to create the following implementation:

public static T CreateProxyObject<T>(Dictionary<String,Object> setup) where T : class
{
   return setup.Aggregate(
          (IDictionary<string, object>) new ExpandoObject(),
            (e, kvSetup) =>
                {
                    e.Add(kvSetup.Key, kvSetup.Value);
                    return e;
                }).ActLike<T>();

 }

That can be used like this:

public interface IPerson
{
    string Name { get; set; }
    int Age { get; set; }
    void Method();
}



public class Program
{
    static void Main(string[] args)
    {
       //Dynamic Expando object
        var p = CreateProxyObject<IPerson>(new Dictionary<string, object>
                                       {
                                           {"Name", "a name"},
                                           {"Age", 13}
                                       });
        var n = p.Name;
        var a = p.Age;
        //Throws: 'System.Dynamic.ExpandoObject' does not contain a definition for 'Method'
        p.Method();
    }
}

Creating Proxy/Mock Object From/Of Generic Type

2 Answers2