Add support for Redirect preserving method/body (HTTP 307 and 308) (dotnet#9968)

Author: huysentruitw

src/Http/Http.Extensions/ref/Microsoft.AspNetCore.Http.Extensions.netcoreapp3.0.cs

@@ -12,6 +12,7 @@ public static void AppendList<T>(this Microsoft.AspNetCore.Http.IHeaderDictionar
     public static partial class ResponseExtensions
     {
         public static void Clear(this Microsoft.AspNetCore.Http.HttpResponse response) { }
+        public static void Redirect(this Microsoft.AspNetCore.Http.HttpResponse response, string location, bool permanent, bool preserveMethod) { }
     }
     public static partial class SendFileResponseExtensions
     {

src/Http/Http.Extensions/src/ResponseExtensions.cs

@@ -3,6 +3,7 @@
 
 using System;
 using Microsoft.AspNetCore.Http.Features;
+using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNetCore.Http
 {
@@ -22,5 +23,26 @@ public static void Clear(this HttpResponse response)
                 response.Body.SetLength(0);
             }
         }
+
+        /// <summary>
+        /// Returns a redirect response (HTTP 301, HTTP 302, HTTP 307 or HTTP 308) to the client.
+        /// </summary>
+        /// <param name="response">The <see cref="HttpResponse"/> to redirect.</param>
+        /// <param name="location">The URL to redirect the client to. This must be properly encoded for use in http headers where only ASCII characters are allowed.</param>
+        /// <param name="permanent"><c>True</c> if the redirect is permanent (301 or 308), otherwise <c>false</c> (302 or 307).</param>
+        /// <param name="preserveMethod"><c>True</c> if the redirect needs to reuse the method and body (308 or 307), otherwise <c>false</c> (301 or 302).</param>
+        public static void Redirect(this HttpResponse response, string location, bool permanent, bool preserveMethod)
+        {
+            if (preserveMethod)
+            {
+                response.StatusCode = permanent ? StatusCodes.Status308PermanentRedirect : StatusCodes.Status307TemporaryRedirect;
+            }
+            else
+            {
+                response.StatusCode = permanent ? StatusCodes.Status301MovedPermanently : StatusCodes.Status302Found;
+            }
+
+            response.Headers[HeaderNames.Location] = location;
+        }
     }
 }

src/Http/Http.Extensions/test/ResponseExtensionTests.cs

@@ -3,8 +3,11 @@
 
 using System;
 using System.IO;
+using System.Linq;
+using System.Net;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http.Features;
+using Microsoft.Net.Http.Headers;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Http.Extensions
@@ -35,6 +38,23 @@ public void Clear_AlreadyStarted_Throws()
             Assert.Throws<InvalidOperationException>(() => context.Response.Clear());
         }
 
+        [Theory]
+        [InlineData(true, false, 301)]
+        [InlineData(false, false, 302)]
+        [InlineData(true, true, 308)]
+        [InlineData(false, true, 307)]
+        public void Redirect_SetsResponseCorrectly(bool permanent, bool preserveMethod, int expectedStatusCode)
+        {
+            var location = "http://localhost/redirect";
+            var context = new DefaultHttpContext();
+            context.Response.StatusCode = StatusCodes.Status200OK;
+
+            context.Response.Redirect(location, permanent, preserveMethod);
+
+            Assert.Equal(location, context.Response.Headers[HeaderNames.Location].First());
+            Assert.Equal(expectedStatusCode, context.Response.StatusCode);
+        }
+
         private class StartedResponseFeature : IHttpResponseFeature
         {
             public Stream Body { get; set; }