tmenier#673 HttpTest Response based on request

Allow HttpTest.RespondWith to access the request when constructing the response.

Test/Flurl.Test/Http/TestingTests.cs

@@ -3,6 +3,7 @@
 using System.Net.Http;
 using System.Threading.Tasks;
 using Flurl.Http;
+using Flurl.Http.Content;
 using Flurl.Http.Testing;
 using NUnit.Framework;
 
@@ -499,5 +500,21 @@ public async Task can_use_response_queue_in_parallel() {
 				}
 			}
 		}
+
+		[Test] // #673
+		public async Task can_use_request_in_response()
+		{
+			HttpTest.RespondWith(request =>
+			{
+				var requestBody = request.Content.ReadAsStringAsync().GetAwaiter().GetResult();
+				return new CapturedStringContent(requestBody);
+			});
+
+			var receivedString = await "http://api.com"
+				.PostStringAsync("hello world")
+				.ReceiveString();
+
+			Assert.AreEqual("hello world", receivedString);
+		}
 	}
 }

src/Flurl.Http/Testing/FakeHttpMessageHandler.cs

@@ -30,7 +30,7 @@ protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage reques
 					HttpTest.Current.LogCall(call);
 					var setup = HttpTest.Current.FindSetup(call);
 					if (setup?.FakeRequest == true) {
-						var resp = setup.GetNextResponse() ?? new HttpResponseMessage {
+						var resp = setup.GetNextResponse(request) ?? new HttpResponseMessage {
 							StatusCode = HttpStatusCode.OK,
 							Content = new StringContent("")
 						};

src/Flurl.Http/Testing/HttpTestSetup.cs

@@ -15,7 +15,7 @@ namespace Flurl.Http.Testing
 	/// </summary>
 	public abstract class HttpTestSetup
 	{
-		private readonly List<Func<HttpResponseMessage>> _responses = new List<Func<HttpResponseMessage>>();
+		private readonly List<Func<HttpRequestMessage, HttpResponseMessage>> _responses = new List<Func<HttpRequestMessage, HttpResponseMessage>>();
 
 		private int _respIndex = 0;
 		private bool _allowRealHttp = false;
@@ -35,12 +35,12 @@ protected HttpTestSetup(TestFlurlHttpSettings settings) {
 
 		internal bool FakeRequest => !_allowRealHttp;
 
-		internal HttpResponseMessage GetNextResponse() {
+		internal HttpResponseMessage GetNextResponse(HttpRequestMessage request) {
 			if (!_responses.Any())
 				return null;
 
 			// atomically get the next response in the list, or the last one if we're past the end
-			return _responses[Math.Min(Interlocked.Increment(ref _respIndex), _responses.Count) - 1]();
+			return _responses[Math.Min(Interlocked.Increment(ref _respIndex), _responses.Count) - 1](request);
 		}
 
 		/// <summary>
@@ -79,11 +79,25 @@ public HttpTestSetup RespondWithJson(object body, int status = 200, object heade
 		/// <param name="cookies">The simulated response cookies. Optional.</param>
 		/// <param name="replaceUnderscoreWithHyphen">If true, underscores in property names of headers will be replaced by hyphens. Default is true.</param>
 		/// <returns>The current HttpTest object (so more responses can be chained).</returns>
-		public HttpTestSetup RespondWith(Func<HttpContent> buildContent = null, int status = 200, object headers = null, object cookies = null, bool replaceUnderscoreWithHyphen = true) {
-			_responses.Add(() => {
+		public HttpTestSetup RespondWith(Func<HttpContent> buildContent, int status = 200, object headers = null, object cookies = null, bool replaceUnderscoreWithHyphen = true)
+		{
+			return RespondWith(request => buildContent?.Invoke(), status, headers, cookies, replaceUnderscoreWithHyphen);
+		}
+
+		/// <summary>
+		/// Adds a fake HTTP response to the response queue.
+		/// </summary>
+		/// <param name="buildContent">A function that builds the simulated response body content. Optional.</param>
+		/// <param name="status">The simulated HTTP status. Optional. Default is 200.</param>
+		/// <param name="headers">The simulated response headers. Optional.</param>
+		/// <param name="cookies">The simulated response cookies. Optional.</param>
+		/// <param name="replaceUnderscoreWithHyphen">If true, underscores in property names of headers will be replaced by hyphens. Default is true.</param>
+		/// <returns>The current HttpTest object (so more responses can be chained).</returns>
+		public HttpTestSetup RespondWith(Func<HttpRequestMessage, HttpContent> buildContent = null, int status = 200, object headers = null, object cookies = null, bool replaceUnderscoreWithHyphen = true) {
+			return RespondWith(request => {
 				var response = new HttpResponseMessage {
 					StatusCode = (HttpStatusCode)status,
-					Content = buildContent?.Invoke()
+					Content = buildContent?.Invoke(request)
 				};
 
 				if (headers != null) {
@@ -99,14 +113,23 @@ public HttpTestSetup RespondWith(Func<HttpContent> buildContent = null, int stat
 				}
 				return response;
 			});
+		}
+
+		/// <summary>
+		/// Adds a fake HTTP response to the response queue.
+		/// </summary>
+		/// <param name="buildResponse">A function that builds the simulated response.</param>
+		/// <returns>The current HttpTest object (so more responses can be chained).</returns>
+		public HttpTestSetup RespondWith(Func<HttpRequestMessage, HttpResponseMessage> buildResponse) {
+			_responses.Add(buildResponse);
 			return this;
 		}
 
 		/// <summary>
 		/// Adds a simulated timeout response to the response queue.
 		/// </summary>
 		public HttpTestSetup SimulateTimeout() {
-			_responses.Add(() => new TimeoutResponseMessage());
+			_responses.Add(request => new TimeoutResponseMessage());
 			return this;
 		}