IsRestrictedResponseHeader (#228)

src/WireMock.Net/Http/HttpKnownHeaderNames.cs

@@ -2,6 +2,9 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System;
+using System.Linq;
+
 namespace WireMock.Http
 {
     /// <summary>
@@ -9,6 +12,29 @@ namespace WireMock.Http
     /// </summary>
     internal static class HttpKnownHeaderNames
     {
+        // https://docs.microsoft.com/en-us/dotnet/api/system.net.webheadercollection.isrestricted
+        private static readonly string[] RestrictedResponseHeaders =
+        {
+            Accept,
+            Connection,
+            ContentLength,
+            ContentType,
+            Date,
+            Expect,
+            Host,
+            IfModifiedSince,
+            Range,
+            Referer,
+            TransferEncoding,
+            UserAgent,
+            ProxyConnection
+        };
+
+        /// <summary>Tests whether the specified HTTP header can be set for the response.</summary>
+        /// <param name="headerName">The header to test.</param>
+        /// <returns>true if the header is restricted; otherwise, false.</returns>
+        public static bool IsRestrictedResponseHeader(string headerName) => RestrictedResponseHeaders.Contains(headerName, StringComparer.OrdinalIgnoreCase);
+
         public const string Accept = "Accept";
         public const string AcceptCharset = "Accept-Charset";
         public const string AcceptEncoding = "Accept-Encoding";

src/WireMock.Net/Owin/Mappers/OwinResponseMapper.cs

@@ -8,8 +8,6 @@ using Newtonsoft.Json;
 using WireMock.Http;
 using WireMock.Util;
 #if !USE_ASPNETCORE
-using System.Net;
-using Microsoft.Owin;
 using IResponse = Microsoft.Owin.IOwinResponse;
 #else
 using Microsoft.AspNetCore.Http;
@@ -85,16 +83,15 @@ namespace WireMock.Owin.Mappers
                 }
                 else
                 {
-#if !USE_ASPNETCORE
-                    // For non-NETSTANDARD, check if this response header can be added (#148)
-                    if (!WebHeaderCollection.IsRestricted(pair.Key, true))
+                    // Check if this response header can be added (#148 and #227)
+                    if (!HttpKnownHeaderNames.IsRestrictedResponseHeader(pair.Key))
                     {
+#if !USE_ASPNETCORE
                         response.Headers.AppendValues(pair.Key, pair.Value.ToArray());
-                    }
 #else
-                    // NETSTANDARD can add any header (or so it seems)
-                    response.Headers.Append(pair.Key, pair.Value.ToArray());
+                        response.Headers.Append(pair.Key, pair.Value.ToArray());
 #endif
+                    }
                 }
             }
         }