Merge pull request #14 from ppittle/multiple-creators-per-session

added HttpWebRequestWrapperDelegateCreator

Author: ppittle

README.md

@@ -251,6 +251,25 @@ using(new HttpWebRequestWrapperSession(new CustomWrapperCreator()))
 }
 ```
 
+### Multiple WebRequestCreate
+
+Have an advanced scenario where you need to use multiple `IWebRequestCreate` objects?  You can use the `HttpWebRequestWrapperDelegateCreator` to decide just-in-time which `IWebRequestCreate` to use for a specific Uri:
+
+```csharp
+var creatorSelector = new Func<Uri, IWebRequestCreate>(url =>
+    url.Contains("api1")
+        ? api1InterceptorCreator
+        : commonInterceptorCreator);
+
+using (new HttpWebRequestWrapperSession(new HttpWebRequestWrapperDelegateCreator(creatorSelector)))
+{
+    // handled by api1Interceptor
+    WebRequest.Create("http://3rdParty.com/api1/request");
+    // handled by commonInterceptor
+    WebRequest.Create("http://someother.site");
+}
+```
+
 ## Secret Sauce
 
 **HttpWebRequestWrapper** works by inheriting from `HttpWebRequest`.  This doesn't seem revolutionary, except these are the `HttpWebRequest` constructors:

src/HttpWebRequestWrapper.Tests/DelegateCreatorTests.cs

@@ -0,0 +1,69 @@
+using System;
+using System.Net;
+using Moq;
+using Should;
+using Xunit;
+
+namespace HttpWebRequestWrapper.Tests
+{
+    /// <summary>
+    /// Tests for <see cref="HttpWebRequestWrapperDelegateCreator"/>
+    /// </summary>
+    public class DelegateCreatorTests
+    {
+        [Fact]
+        public void CanUseMultipleWebRequestCreators()
+        {
+            // ARRANGE
+            var url1 = new Uri("http://fakesite.fake/1");
+            var url2 = new Uri("http://fakesite.fake/2");
+
+            var mockRequest1 = new Mock<WebRequest>();
+            var mockRequest2 = new Mock<WebRequest>();
+
+            var mockRequestCreator1 = new Mock<IWebRequestCreate>();
+            mockRequestCreator1
+                .Setup(x => x.Create(It.IsAny<Uri>()))
+                .Returns(mockRequest1.Object);
+
+            var mockRequestCreator2 = new Mock<IWebRequestCreate>();
+            mockRequestCreator2
+                .Setup(x => x.Create(It.IsAny<Uri>()))
+                .Returns(mockRequest2.Object);
+
+            var creatorSelector = new Func<Uri, IWebRequestCreate>(url =>
+                url == url1
+                    ? mockRequestCreator1.Object
+                    : mockRequestCreator2.Object);
+
+            var delegateCreator = new HttpWebRequestWrapperDelegateCreator(creatorSelector);
+            
+            WebRequest request1, request2;
+
+            // ACT
+            using (new HttpWebRequestWrapperSession(delegateCreator))
+            {
+                request1 = WebRequest.Create(url1);
+                request2 = WebRequest.Create(url2);
+            }
+
+            // ASSERT
+            request1.ShouldEqual(mockRequest1.Object);
+            request2.ShouldEqual(mockRequest2.Object);
+
+            mockRequestCreator1.Verify(x => 
+                    x.Create(It.Is<Uri>(v => v == url1)),
+                Times.Once);
+            mockRequestCreator1.Verify(x => 
+                    x.Create(It.Is<Uri>(v => v == url2)),
+                Times.Never);
+
+            mockRequestCreator2.Verify(x => 
+                    x.Create(It.Is<Uri>(v => v == url1)),
+                Times.Never);
+            mockRequestCreator2.Verify(x => 
+                    x.Create(It.Is<Uri>(v => v == url2)),
+                Times.Once);
+        }
+    }
+}

src/HttpWebRequestWrapper.Tests/HttpWebRequestWrapper.Tests.csproj

@@ -85,6 +85,7 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="DelegateCreatorTests.cs" />
     <Compile Include="InterceptorTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Properties\Extensions.cs" />

src/HttpWebRequestWrapper/HttpWebRequestWrapper.csproj

@@ -50,6 +50,7 @@
   <ItemGroup>
     <Compile Include="Extensions\RecordedRequestExtensions.cs" />
     <Compile Include="Extensions\StringExtensions.cs" />
+    <Compile Include="HttpWebRequestWrapperDelegateCreator.cs" />
     <Compile Include="HttpWebRequestWrapperInterceptor.cs" />
     <Compile Include="HttpWebRequestWrapperInterceptorCreator.cs" />
     <Compile Include="HttpWebRequestWrapperRecorder.cs" />

src/HttpWebRequestWrapper/HttpWebRequestWrapperDelegateCreator.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Net;
+
+namespace HttpWebRequestWrapper
+{
+    /// <summary>
+    /// Helper component that supports just-in-time selection of a 
+    /// <see cref="IWebRequestCreate"/> based on the requested <see cref="Uri"/>.
+    /// <para />
+    /// This is only anticipated to be useful when writing BDD style
+    /// tests that cover a large application surface area - where the system
+    /// might be making calls to two different api endpoints and it is helpful to 
+    /// have requests be routed to different <see cref="IWebRequestCreate"/>s 
+    /// (ie <see cref="HttpWebRequestWrapperInterceptorCreator"/>) based on url.
+    /// <para />
+    /// For example, requests to http://api1/ could go to one Interceptor with a specific
+    /// <see cref="RecordingSession"/> and playback behavior and requests to http://api2/
+    /// could go to a different Interceptor with its own <see cref="RecordingSession"/>
+    /// and different playback behavior. 
+    /// </summary>
+    public class HttpWebRequestWrapperDelegateCreator : IWebRequestCreate
+    {
+        private readonly Func<Uri, IWebRequestCreate> _creatorSelectorFunc;
+
+        /// <summary>
+        /// Helper component that supports just-in-time selection of a 
+        /// <see cref="IWebRequestCreate"/> based on the requested <see cref="Uri"/>
+        /// via <paramref name="creatorSelector"/>.
+        /// <para />
+        /// This is only anticipated to be useful when writing BDD style
+        /// tests that cover a large application surface area - where the system
+        /// might be making calls to two different api endpoints and it is helpful to 
+        /// have requests be routed to different <see cref="IWebRequestCreate"/>s 
+        /// (ie <see cref="HttpWebRequestWrapperInterceptorCreator"/>) based on url.
+        /// <para />
+        /// For example, requests to http://api1/ could go to one Interceptor with a specific
+        /// <see cref="RecordingSession"/> and playback behavior and requests to http://api2/
+        /// could go to a different Interceptor with its own <see cref="RecordingSession"/>
+        /// and different playback behavior. 
+        /// </summary>
+        public HttpWebRequestWrapperDelegateCreator(Func<Uri, IWebRequestCreate> creatorSelector)
+        {
+            _creatorSelectorFunc = creatorSelector;
+        }
+
+        /// <inheritdoc />
+        public WebRequest Create(Uri uri)
+        {
+            return _creatorSelectorFunc(uri).Create(uri);
+        }
+    }
+}