ICallbackResponseBuilder + added more unit-tests (#101)

* Callback

* Add more tests

src/WireMock.Net/ResponseProviders/DynamicAsyncResponseProvider.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Threading.Tasks;
+using JetBrains.Annotations;
+using WireMock.Validation;
+
+namespace WireMock.ResponseProviders
+{
+    internal class DynamicAsyncResponseProvider : IResponseProvider
+    {
+        private readonly Func<RequestMessage, Task<ResponseMessage>> _responseMessageFunc;
+
+        public DynamicAsyncResponseProvider([NotNull] Func<RequestMessage, Task<ResponseMessage>> responseMessageFunc)
+        {
+            Check.NotNull(responseMessageFunc, nameof(responseMessageFunc));
+
+            _responseMessageFunc = responseMessageFunc;
+        }
+
+        public Task<ResponseMessage> ProvideResponseAsync(RequestMessage requestMessage)
+        {
+            return _responseMessageFunc(requestMessage);
+        }
+    }
+}

src/WireMock.Net/ResponseProviders/DynamicResponseProvider.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Threading.Tasks;
+using JetBrains.Annotations;
+using WireMock.Validation;
+
+namespace WireMock.ResponseProviders
+{
+    internal class DynamicResponseProvider : IResponseProvider
+    {
+        private readonly Func<RequestMessage, ResponseMessage> _responseMessageFunc;
+
+        public DynamicResponseProvider([NotNull] Func<RequestMessage, ResponseMessage> responseMessageFunc)
+        {
+            Check.NotNull(responseMessageFunc, nameof(responseMessageFunc));
+
+            _responseMessageFunc = responseMessageFunc;
+        }
+
+        public Task<ResponseMessage> ProvideResponseAsync(RequestMessage requestMessage)
+        {
+            return Task.FromResult(_responseMessageFunc(requestMessage));
+        }
+    }
+}

src/WireMock.Net/ResponseProviders/IResponseProvider.cs

@@ -0,0 +1,18 @@
+using System.Threading.Tasks;
+using JetBrains.Annotations;
+
+namespace WireMock.ResponseProviders
+{
+    /// <summary>
+    /// The Response Provider interface.
+    /// </summary>
+    public interface IResponseProvider
+    {
+        /// <summary>
+        /// The provide response.
+        /// </summary>
+        /// <param name="requestMessage">The request.</param>
+        /// <returns>The <see cref="ResponseMessage"/>.</returns>
+        Task<ResponseMessage> ProvideResponseAsync([NotNull] RequestMessage requestMessage);
+    }
+}

src/WireMock.Net/ResponseProviders/ProxyAsyncResponseProvider.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Threading.Tasks;
+using JetBrains.Annotations;
+using WireMock.Settings;
+using WireMock.Validation;
+
+namespace WireMock.ResponseProviders
+{
+    internal class ProxyAsyncResponseProvider : IResponseProvider
+    {
+        private readonly Func<RequestMessage, IProxyAndRecordSettings, Task<ResponseMessage>> _responseMessageFunc;
+        private readonly IProxyAndRecordSettings _settings;
+
+        public ProxyAsyncResponseProvider([NotNull] Func<RequestMessage, IProxyAndRecordSettings, Task<ResponseMessage>> responseMessageFunc, [NotNull] IProxyAndRecordSettings settings)
+        {
+            Check.NotNull(responseMessageFunc, nameof(responseMessageFunc));
+            Check.NotNull(settings, nameof(settings));
+
+            _responseMessageFunc = responseMessageFunc;
+            _settings = settings;
+        }
+
+        public Task<ResponseMessage> ProvideResponseAsync(RequestMessage requestMessage)
+        {
+            return _responseMessageFunc(requestMessage, _settings);
+        }
+    }
+}