Relocate improvements to HttpAbstractions

src/Microsoft.AspNetCore.ResponseCaching/CacheControlValues.cs

@@ -1,21 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-namespace Microsoft.AspNetCore.ResponseCaching.Internal
-{
-    internal class CacheControlValues
-    {
-        public const string MaxAgeString = "max-age";
-        public const string MaxStaleString = "max-stale";
-        public const string MinFreshString = "min-fresh";
-        public const string MustRevalidateString = "must-revalidate";
-        public const string NoCacheString = "no-cache";
-        public const string NoStoreString = "no-store";
-        public const string NoTransformString = "no-transform";
-        public const string OnlyIfCachedString = "only-if-cached";
-        public const string PrivateString = "private";
-        public const string ProxyRevalidateString = "proxy-revalidate";
-        public const string PublicString = "public";
-        public const string SharedMaxAgeString = "s-maxage";
-    }
-}

src/Microsoft.AspNetCore.ResponseCaching/Internal/HttpHeaderParsingHelpers.cs

@@ -1,118 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System;
-using System.Globalization;
-using Microsoft.Extensions.Primitives;
-
-namespace Microsoft.AspNetCore.ResponseCaching.Internal
-{
-    internal static class HttpHeaderParsingHelpers
-    {
-        private static readonly string[] DateFormats = new string[] {
-            // "r", // RFC 1123, required output format but too strict for input
-            "ddd, d MMM yyyy H:m:s 'GMT'", // RFC 1123 (r, except it allows both 1 and 01 for date and time)
-            "ddd, d MMM yyyy H:m:s", // RFC 1123, no zone - assume GMT
-            "d MMM yyyy H:m:s 'GMT'", // RFC 1123, no day-of-week
-            "d MMM yyyy H:m:s", // RFC 1123, no day-of-week, no zone
-            "ddd, d MMM yy H:m:s 'GMT'", // RFC 1123, short year
-            "ddd, d MMM yy H:m:s", // RFC 1123, short year, no zone
-            "d MMM yy H:m:s 'GMT'", // RFC 1123, no day-of-week, short year
-            "d MMM yy H:m:s", // RFC 1123, no day-of-week, short year, no zone
-
-            "dddd, d'-'MMM'-'yy H:m:s 'GMT'", // RFC 850
-            "dddd, d'-'MMM'-'yy H:m:s", // RFC 850 no zone
-            "ddd MMM d H:m:s yyyy", // ANSI C's asctime() format
-
-            "ddd, d MMM yyyy H:m:s zzz", // RFC 5322
-            "ddd, d MMM yyyy H:m:s", // RFC 5322 no zone
-            "d MMM yyyy H:m:s zzz", // RFC 5322 no day-of-week
-            "d MMM yyyy H:m:s", // RFC 5322 no day-of-week, no zone
-        };
-
-        // Try the various date formats in the order listed above.
-        // We should accept a wide verity of common formats, but only output RFC 1123 style dates.
-        internal static bool TryParseHeaderDate(string input, out DateTimeOffset result) => DateTimeOffset.TryParseExact(input, DateFormats, DateTimeFormatInfo.InvariantInfo,
-                DateTimeStyles.AllowWhiteSpaces | DateTimeStyles.AssumeUniversal, out result);
-
-        // Try to get the value of a specific header from a list of headers
-        // e.g. "header1=10, header2=30"
-        internal static bool TryParseHeaderTimeSpan(StringValues headers, string headerName, out TimeSpan? value)
-        {
-            foreach (var header in headers)
-            {
-                var index = header.IndexOf(headerName, StringComparison.OrdinalIgnoreCase);
-                if (index != -1)
-                {
-                    index += headerName.Length;
-                    int seconds;
-                    if (!TryParseHeaderInt(index, header, out seconds))
-                    {
-                        break;
-                    }
-                    value = TimeSpan.FromSeconds(seconds);
-                    return true;
-                }
-            }
-            value = null;
-            return false;
-        }
-
-        internal static bool HeaderContains(StringValues headers, string headerName)
-        {
-            foreach (var header in headers)
-            {
-                var index = header.IndexOf(headerName, StringComparison.OrdinalIgnoreCase);
-                if (index != -1)
-                {
-                    return true;
-                }
-            }
-
-            return false;
-        }
-
-        private static bool TryParseHeaderInt(int startIndex, string header, out int value)
-        {
-            var found = false;
-            while (startIndex != header.Length)
-            {
-                var c = header[startIndex];
-                if (c == '=')
-                {
-                    found = true;
-                }
-                else if (c != ' ')
-                {
-                    --startIndex;
-                    break;
-                }
-                ++startIndex;
-            }
-            if (found && startIndex != header.Length)
-            {
-                var endIndex = startIndex + 1;
-                while (endIndex < header.Length)
-                {
-                    var c = header[endIndex];
-                    if ((c >= '0') && (c <= '9'))
-                    {
-                        endIndex++;
-                    }
-                    else
-                    {
-                        break;
-                    }
-                }
-                var length = endIndex - (startIndex + 1);
-                if (length > 0)
-                {
-                    value = int.Parse(header.Substring(startIndex + 1, length), NumberStyles.None, NumberFormatInfo.InvariantInfo);
-                    return true;
-                }
-            }
-            value = 0;
-            return false;
-        }
-    }
-}

src/Microsoft.AspNetCore.ResponseCaching/Internal/ResponseCachingContext.cs

@@ -65,7 +65,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
                 {
                     _parsedResponseDate = true;
                     DateTimeOffset date;
-                    if (HttpHeaderParsingHelpers.TryParseHeaderDate(HttpContext.Response.Headers[HeaderNames.Date], out date))
+                    if (HeaderUtilities.TryParseDate(HttpContext.Response.Headers[HeaderNames.Date], out date))
                     {
                         _responseDate = date;
                     }
@@ -92,7 +92,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
                 {
                     _parsedResponseExpires = true;
                     DateTimeOffset expires;
-                    if (HttpHeaderParsingHelpers.TryParseHeaderDate(HttpContext.Response.Headers[HeaderNames.Expires], out expires))
+                    if (HeaderUtilities.TryParseDate(HttpContext.Response.Headers[HeaderNames.Expires], out expires))
                     {
                         _responseExpires = expires;
                     }
@@ -112,7 +112,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
                 if (!_parsedResponseSharedMaxAge)
                 {
                     _parsedResponseSharedMaxAge = true;
-                    HttpHeaderParsingHelpers.TryParseHeaderTimeSpan(HttpContext.Response.Headers[HeaderNames.CacheControl], CacheControlValues.SharedMaxAgeString, out _responseSharedMaxAge);
+                    HeaderUtilities.TryParseSeconds(HttpContext.Response.Headers[HeaderNames.CacheControl], CacheControlHeaderValue.SharedMaxAgeString, out _responseSharedMaxAge);
                 }
                 return _responseSharedMaxAge;
             }
@@ -125,7 +125,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
                 if (!_parsedResponseMaxAge)
                 {
                     _parsedResponseMaxAge = true;
-                    HttpHeaderParsingHelpers.TryParseHeaderTimeSpan(HttpContext.Response.Headers[HeaderNames.CacheControl], CacheControlValues.MaxAgeString, out _responseMaxAge);
+                    HeaderUtilities.TryParseSeconds(HttpContext.Response.Headers[HeaderNames.CacheControl], CacheControlHeaderValue.MaxAgeString, out _responseMaxAge);
                 }
                 return _responseMaxAge;
             }

src/Microsoft.AspNetCore.ResponseCaching/Internal/ResponseCachingPolicyProvider.cs

@@ -30,7 +30,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
             // Verify request cache-control parameters
             if (!StringValues.IsNullOrEmpty(request.Headers[HeaderNames.CacheControl]))
             {
-                if (HttpHeaderParsingHelpers.HeaderContains(request.Headers[HeaderNames.CacheControl], CacheControlValues.NoCacheString))
+                if (HeaderUtilities.ContainsCacheDirective(request.Headers[HeaderNames.CacheControl], CacheControlHeaderValue.NoCacheString))
                 {
                     context.Logger.LogRequestWithNoCacheNotCacheable();
                     return false;
@@ -40,7 +40,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
             {
                 // Support for legacy HTTP 1.0 cache directive
                 var pragmaHeaderValues = request.Headers[HeaderNames.Pragma];
-                if (HttpHeaderParsingHelpers.HeaderContains(request.Headers[HeaderNames.Pragma], CacheControlValues.NoCacheString))
+                if (HeaderUtilities.ContainsCacheDirective(request.Headers[HeaderNames.Pragma], CacheControlHeaderValue.NoCacheString))
                 {
                     context.Logger.LogRequestWithPragmaNoCacheNotCacheable();
                     return false;
@@ -55,27 +55,22 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
             var responseCacheControlHeader = context.HttpContext.Response.Headers[HeaderNames.CacheControl];
 
             // Only cache pages explicitly marked with public
-            if (!HttpHeaderParsingHelpers.HeaderContains(responseCacheControlHeader, CacheControlValues.PublicString))
+            if (!HeaderUtilities.ContainsCacheDirective(responseCacheControlHeader, CacheControlHeaderValue.PublicString))
             {
                 context.Logger.LogResponseWithoutPublicNotCacheable();
                 return false;
             }
 
             // Check no-store
-            if (HttpHeaderParsingHelpers.HeaderContains(context.HttpContext.Request.Headers[HeaderNames.CacheControl], CacheControlValues.NoStoreString))
+            if (HeaderUtilities.ContainsCacheDirective(context.HttpContext.Request.Headers[HeaderNames.CacheControl], CacheControlHeaderValue.NoStoreString)
-            {
+                || HeaderUtilities.ContainsCacheDirective(responseCacheControlHeader, CacheControlHeaderValue.NoStoreString))
-                context.Logger.LogResponseWithNoStoreNotCacheable();
-                return false;
-            }
-
-            if (HttpHeaderParsingHelpers.HeaderContains(responseCacheControlHeader, CacheControlValues.NoStoreString))
             {
                 context.Logger.LogResponseWithNoStoreNotCacheable();
                 return false;
             }
 
             // Check no-cache
-            if (HttpHeaderParsingHelpers.HeaderContains(responseCacheControlHeader, CacheControlValues.NoCacheString))
+            if (HeaderUtilities.ContainsCacheDirective(responseCacheControlHeader, CacheControlHeaderValue.NoCacheString))
             {
                 context.Logger.LogResponseWithNoCacheNotCacheable();
                 return false;
@@ -99,7 +94,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
             }
 
             // Check private
-            if (HttpHeaderParsingHelpers.HeaderContains(responseCacheControlHeader, CacheControlValues.PrivateString))
+            if (HeaderUtilities.ContainsCacheDirective(responseCacheControlHeader, CacheControlHeaderValue.PrivateString))
             {
                 context.Logger.LogResponseWithPrivateNotCacheable();
                 return false;
@@ -159,12 +154,12 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
         public virtual bool IsCachedEntryFresh(ResponseCachingContext context)
         {
             var age = context.CachedEntryAge.Value;
-            var cachedControlHeaders = context.CachedResponseHeaders[HeaderNames.CacheControl];
+            var cachedCacheControlHeaders = context.CachedResponseHeaders[HeaderNames.CacheControl];
             var requestCacheControlHeaders = context.HttpContext.Request.Headers[HeaderNames.CacheControl];
 
             // Add min-fresh requirements
             TimeSpan? minFresh;
-            if (HttpHeaderParsingHelpers.TryParseHeaderTimeSpan(requestCacheControlHeaders, CacheControlValues.MinFreshString, out minFresh))
+            if (HeaderUtilities.TryParseSeconds(requestCacheControlHeaders, CacheControlHeaderValue.MinFreshString, out minFresh))
             {
                 age += minFresh.Value;
                 context.Logger.LogExpirationMinFreshAdded(minFresh.Value);
@@ -172,7 +167,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
 
             // Validate shared max age, this overrides any max age settings for shared caches
             TimeSpan? cachedSharedMaxAge;
-            HttpHeaderParsingHelpers.TryParseHeaderTimeSpan(cachedControlHeaders, CacheControlValues.SharedMaxAgeString, out cachedSharedMaxAge);
+            HeaderUtilities.TryParseSeconds(cachedCacheControlHeaders, CacheControlHeaderValue.SharedMaxAgeString, out cachedSharedMaxAge);
 
             if (age >= cachedSharedMaxAge)
             {
@@ -183,24 +178,24 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
             else if (!cachedSharedMaxAge.HasValue)
             {
                 TimeSpan? requestMaxAge;
-                HttpHeaderParsingHelpers.TryParseHeaderTimeSpan(requestCacheControlHeaders, CacheControlValues.MaxAgeString, out requestMaxAge);
+                HeaderUtilities.TryParseSeconds(requestCacheControlHeaders, CacheControlHeaderValue.MaxAgeString, out requestMaxAge);
 
                 TimeSpan? cachedMaxAge;
-                HttpHeaderParsingHelpers.TryParseHeaderTimeSpan(cachedControlHeaders, CacheControlValues.MaxAgeString, out cachedMaxAge);
+                HeaderUtilities.TryParseSeconds(cachedCacheControlHeaders, CacheControlHeaderValue.MaxAgeString, out cachedMaxAge);
 
                 var lowestMaxAge = cachedMaxAge < requestMaxAge ? cachedMaxAge : requestMaxAge ?? cachedMaxAge;
                 // Validate max age
                 if (age >= lowestMaxAge)
                 {
                     // Must revalidate
-                    if (HttpHeaderParsingHelpers.HeaderContains(cachedControlHeaders, CacheControlValues.MustRevalidateString))
+                    if (HeaderUtilities.ContainsCacheDirective(cachedCacheControlHeaders, CacheControlHeaderValue.MustRevalidateString))
                     {
                         context.Logger.LogExpirationMustRevalidate(age, lowestMaxAge.Value);
                         return false;
                     }
 
                     TimeSpan? requestMaxStale;
-                    HttpHeaderParsingHelpers.TryParseHeaderTimeSpan(requestCacheControlHeaders, CacheControlValues.MaxStaleString, out requestMaxStale);
+                    HeaderUtilities.TryParseSeconds(requestCacheControlHeaders, CacheControlHeaderValue.MaxStaleString, out requestMaxStale);
 
                     // Request allows stale values
                     if (requestMaxStale.HasValue && age - lowestMaxAge < requestMaxStale)
@@ -216,7 +211,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
                 {
                     // Validate expiration
                     DateTimeOffset expires;
-                    if (HttpHeaderParsingHelpers.TryParseHeaderDate(context.CachedResponseHeaders[HeaderNames.Expires], out expires) &&
+                    if (HeaderUtilities.TryParseDate(context.CachedResponseHeaders[HeaderNames.Expires], out expires) &&
                         context.ResponseTime.Value >= expires)
                     {
                         context.Logger.LogExpirationExpiresExceeded(context.ResponseTime.Value, expires);

src/Microsoft.AspNetCore.ResponseCaching/ResponseCachingMiddleware.cs

@@ -2,11 +2,11 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Globalization;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Features;
-using Microsoft.AspNetCore.Http.Headers;
 using Microsoft.AspNetCore.ResponseCaching.Internal;
 using Microsoft.Extensions.Internal;
 using Microsoft.Extensions.Logging;
@@ -198,7 +198,7 @@ namespace Microsoft.AspNetCore.ResponseCaching
                 }
             }
 
-            if (HttpHeaderParsingHelpers.HeaderContains(context.HttpContext.Request.Headers[HeaderNames.CacheControl], CacheControlValues.OnlyIfCachedString))
+            if (HeaderUtilities.ContainsCacheDirective(context.HttpContext.Request.Headers[HeaderNames.CacheControl], CacheControlHeaderValue.OnlyIfCachedString))
             {
                 _logger.LogGatewayTimeoutServed();
                 context.HttpContext.Response.StatusCode = StatusCodes.Status504GatewayTimeout;
@@ -359,26 +359,24 @@ namespace Microsoft.AspNetCore.ResponseCaching
 
             if (!StringValues.IsNullOrEmpty(ifNoneMatchHeader))
             {
-                if (ifNoneMatchHeader.Count == 1 && ifNoneMatchHeader[0].Equals(EntityTagHeaderValue.Any.Tag))
+                if (ifNoneMatchHeader.Count == 1 && string.Equals(ifNoneMatchHeader[0], EntityTagHeaderValue.Any.Tag, StringComparison.OrdinalIgnoreCase))
                 {
                     context.Logger.LogNotModifiedIfNoneMatchStar();
                     return true;
                 }
 
-                if (!StringValues.IsNullOrEmpty(cachedResponseHeaders[HeaderNames.ETag]))
+                EntityTagHeaderValue eTag;
+                IList<EntityTagHeaderValue> ifNoneMatchEtags;
+                if (!StringValues.IsNullOrEmpty(cachedResponseHeaders[HeaderNames.ETag])
+                    && EntityTagHeaderValue.TryParse(cachedResponseHeaders[HeaderNames.ETag], out eTag)
+                    && EntityTagHeaderValue.TryParseList(ifNoneMatchHeader, out ifNoneMatchEtags))
                 {
-                    EntityTagHeaderValue eTag;
+                    foreach (var requestETag in ifNoneMatchEtags)
-                    if (EntityTagHeaderValue.TryParse(cachedResponseHeaders[HeaderNames.ETag], out eTag))
                     {
-                        foreach (var tag in ifNoneMatchHeader)
+                        if (eTag.Compare(requestETag, useStrongComparison: false))
                         {
-                            EntityTagHeaderValue requestETag;
+                            context.Logger.LogNotModifiedIfNoneMatchMatched(requestETag);
-                            if (EntityTagHeaderValue.TryParse(tag, out requestETag) &&
+                            return true;
-                                eTag.Compare(requestETag, useStrongComparison: false))
-                            {
-                                context.Logger.LogNotModifiedIfNoneMatchMatched(requestETag);
-                                return true;
-                            }
                         }
                     }
                 }
@@ -389,14 +387,14 @@ namespace Microsoft.AspNetCore.ResponseCaching
                 if (!StringValues.IsNullOrEmpty(ifUnmodifiedSince))
                 {
                     DateTimeOffset modified;
-                    if (!HttpHeaderParsingHelpers.TryParseHeaderDate(cachedResponseHeaders[HeaderNames.LastModified], out modified) &&
+                    if (!HeaderUtilities.TryParseDate(cachedResponseHeaders[HeaderNames.LastModified], out modified) &&
-                        !HttpHeaderParsingHelpers.TryParseHeaderDate(cachedResponseHeaders[HeaderNames.Date], out modified))
+                        !HeaderUtilities.TryParseDate(cachedResponseHeaders[HeaderNames.Date], out modified))
                     {
                         return false;
                     }
 
                     DateTimeOffset unmodifiedSince;
-                    if (HttpHeaderParsingHelpers.TryParseHeaderDate(ifUnmodifiedSince, out unmodifiedSince) &&
+                    if (HeaderUtilities.TryParseDate(ifUnmodifiedSince, out unmodifiedSince) &&
                         modified <= unmodifiedSince)
                     {
                         context.Logger.LogNotModifiedIfUnmodifiedSinceSatisfied(modified, unmodifiedSince);

test/Microsoft.AspNetCore.ResponseCaching.Tests/ParsingHelpersTests.cs

@@ -1,39 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System;
-using Microsoft.AspNetCore.ResponseCaching.Internal;
-using Microsoft.Extensions.Primitives;
-using Xunit;
-
-namespace Microsoft.AspNetCore.ResponseCaching.Tests
-{
-    public class ParsingHelpersTests
-    {
-        [Theory]
-        [InlineData("h=1", "h", 1)]
-        [InlineData("header1=3, header2=10", "header1", 3)]
-        [InlineData("header1   =45, header2=80", "header1", 45)]
-        [InlineData("header1=   89   , header2=22", "header1", 89)]
-        [InlineData("header1=   89   , header2= 42", "header2", 42)]
-        void TryGetHeaderValue_Succeeds(string headerValue, string headerName, int expectedValue)
-        {
-            TimeSpan? value;
-            Assert.True(HttpHeaderParsingHelpers.TryParseHeaderTimeSpan(new StringValues(headerValue), headerName, out value));
-            Assert.Equal(TimeSpan.FromSeconds(expectedValue), value);
-        }
-
-        [Theory]
-        [InlineData("h=", "h")]
-        [InlineData("header1=, header2=10", "header1")]
-        [InlineData("header1   , header2=80", "header1")]
-        [InlineData("h=10", "header")]
-        [InlineData("", "")]
-        [InlineData(null, null)]
-        void TryGetHeaderValue_Fails(string headerValue, string headerName)
-        {
-            TimeSpan? value;
-            Assert.False(HttpHeaderParsingHelpers.TryParseHeaderTimeSpan(new StringValues(headerValue), headerName, out value));
-        }
-    }
-}

test/Microsoft.AspNetCore.ResponseCaching.Tests/ResponseCachingMiddlewareTests.cs

@@ -5,7 +5,6 @@ using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Http.Headers;
 using Microsoft.AspNetCore.ResponseCaching.Internal;
 using Microsoft.Extensions.Logging.Testing;
 using Microsoft.Extensions.Primitives;
@@ -251,7 +250,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Tests
             context.HttpContext.Request.Headers[HeaderNames.IfUnmodifiedSince] = HeaderUtilities.FormatDate(utcNow);
             context.CachedResponseHeaders[HeaderNames.LastModified] = HeaderUtilities.FormatDate(utcNow - TimeSpan.FromSeconds(10));
 
-            context.HttpContext.Request.Headers[HeaderNames.IfNoneMatch] = new List<EntityTagHeaderValue>(new[] { new EntityTagHeaderValue("\"E1\"") }).ToString();
+            context.HttpContext.Request.Headers[HeaderNames.IfNoneMatch] = "\"E1\"";
             Assert.False(ResponseCachingMiddleware.ContentIsNotModified(context));
             Assert.Empty(sink.Writes);
         }
@@ -262,8 +261,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Tests
             var sink = new TestSink();
             var context = TestUtils.CreateTestContext(sink);
             context.CachedResponseHeaders = new HeaderDictionary();
-
+            context.HttpContext.Request.Headers[HeaderNames.IfNoneMatch] = "\"E1\"";
-            context.HttpContext.Request.Headers[HeaderNames.IfNoneMatch] = new List<EntityTagHeaderValue>(new[] { new EntityTagHeaderValue("\"E1\"") }).ToString();
 
             Assert.False(ResponseCachingMiddleware.ContentIsNotModified(context));
             Assert.Empty(sink.Writes);
@@ -291,7 +289,6 @@ namespace Microsoft.AspNetCore.ResponseCaching.Tests
             var context = TestUtils.CreateTestContext(sink);
             context.CachedResponseHeaders = new HeaderDictionary();
             context.CachedResponseHeaders[HeaderNames.ETag] = responseETag.ToString();
-
             context.HttpContext.Request.Headers[HeaderNames.IfNoneMatch] = requestETag.ToString();
 
             Assert.True(ResponseCachingMiddleware.ContentIsNotModified(context));
@@ -306,14 +303,28 @@ namespace Microsoft.AspNetCore.ResponseCaching.Tests
             var sink = new TestSink();
             var context = TestUtils.CreateTestContext(sink);
             context.CachedResponseHeaders = new HeaderDictionary();
-            context.HttpContext.Response.Headers[HeaderNames.ETag] = new EntityTagHeaderValue("\"E2\"").ToString();
+            context.CachedResponseHeaders[HeaderNames.ETag] = "\"E2\"";
-
+            context.HttpContext.Request.Headers[HeaderNames.IfNoneMatch] = "\"E1\"";
-            context.HttpContext.Request.Headers[HeaderNames.IfNoneMatch] = new List<EntityTagHeaderValue>(new[] { new EntityTagHeaderValue("\"E1\"") }).ToString();
 
             Assert.False(ResponseCachingMiddleware.ContentIsNotModified(context));
             Assert.Empty(sink.Writes);
         }
 
+        [Fact]
+        public void ContentIsNotModified_IfNoneMatch_MatchesAtLeastOneValue_True()
+        {
+            var sink = new TestSink();
+            var context = TestUtils.CreateTestContext(sink);
+            context.CachedResponseHeaders = new HeaderDictionary();
+            context.CachedResponseHeaders[HeaderNames.ETag] = "\"E2\"";
+            context.HttpContext.Request.Headers[HeaderNames.IfNoneMatch] = new string[] { "\"E0\", \"E1\"", "\"E1\", \"E2\"" };
+
+            Assert.True(ResponseCachingMiddleware.ContentIsNotModified(context));
+            TestUtils.AssertLoggedMessages(
+                sink.Writes,
+                LoggedMessage.NotModifiedIfNoneMatchMatched);
+        }
+
         [Fact]
         public async Task FinalizeCacheHeaders_DoNotUpdateShouldCacheResponse_IfResponseIsNotCacheable()
         {