OBSOLETE: Since Azure Functions Durable Extensions 2.3.0, this technique is no longer needed. Wraps the `DurableEntityProxyExtensions.CreateEntityProxy` extension methods for use in Azure Durable Function Orchestrations unit testing.

EntityProxyCreator.cs

using Microsoft.Azure.WebJobs.Extensions.DurableTask;

namespace K0x.DurableFunctionsHelpers
{
    /// <summary>
    /// Wraps the DurableEntityProxyExtensions.CreateEntityProxy extension methods
    /// for use in durable orchestrations that are unit tested.
    /// </summary>
    /// <remarks>
    /// Instead of using the DurableEntityProxyExtensions.CreateEntityProxy<>(..) extension method
    /// in an orchestration like:
    /// 
    /// var myEntityProxy = context.CreateEntityProxy<IMyEntityProxy>(myEntityId);
    /// 
    /// Use dependency injection to inject an instance of class EntityProxyCreator
    /// into the orchestration class and then us it to create the entity proxy like:
    /// 
    /// var myEntityProxy = _entityProxyCreator.CreateEntityProxy<IMyEntityProxy>(context, myEntityId);
    /// 
    /// </remarks>
    public class EntityProxyCreator : IEntityProxyCreator
    {
        public TEntityInterface CreateEntityProxy<TEntityInterface>(
            IDurableOrchestrationContext context,
            EntityId entityId)
        {
            // Call the extension method.
            return DurableEntityProxyExtensions.CreateEntityProxy<TEntityInterface>(
                context,
                 entityId);
        }
    }
}

IEntityProxyCreator.cs

using Microsoft.Azure.WebJobs.Extensions.DurableTask;

namespace K0x.DurableFunctionsHelpers
{
    public interface IEntityProxyCreator
    {
        TEntityInterface CreateEntityProxy<TEntityInterface>(
            IDurableOrchestrationContext context,
            EntityId entityId);
    }
}