Minor fix and add tests

Author: JunTaoLuo

src/Microsoft.AspNetCore.ResponseCaching/ResponseCachingContext.cs

@@ -522,7 +522,7 @@ internal bool ConditionalRequestSatisfied(ResponseHeaders cachedResponseHeaders)
                     }
                 }
             }
-            else if ((cachedResponseHeaders.LastModified ?? cachedResponseHeaders.Date) < RequestHeaders.IfUnmodifiedSince)
+            else if ((cachedResponseHeaders.LastModified ?? cachedResponseHeaders.Date) <= RequestHeaders.IfUnmodifiedSince)
             {
                 return true;
             }

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

@@ -12,6 +12,7 @@
 using Microsoft.Extensions.ObjectPool;
 using Microsoft.Net.Http.Headers;
 using Xunit;
+using System.Collections.Generic;
 
 namespace Microsoft.AspNetCore.ResponseCaching.Tests
 {
@@ -692,6 +693,140 @@ public void EntryIsFresh_IgnoresRequestVerificationWhenSpecified()
             Assert.True(context.EntryIsFresh(httpContext.Response.GetTypedHeaders(), TimeSpan.FromSeconds(3), verifyAgainstRequest: false));
         }
 
+        [Fact]
+        public void ConditionalRequestSatisfied_NotConditionalRequest_Fails()
+        {
+            var context = CreateTestContext(new DefaultHttpContext());
+            var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
+
+            Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
+        }
+
+        [Fact]
+        public void ConditionalRequestSatisfied_IfUnmodifiedSince_FallsbackToDateHeader()
+        {
+            var utcNow = DateTimeOffset.UtcNow;
+            var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
+            var httpContext = new DefaultHttpContext();
+            var context = CreateTestContext(httpContext);
+
+            httpContext.Request.GetTypedHeaders().IfUnmodifiedSince = utcNow;
+
+            // Verify modifications in the past succeeds
+            cachedHeaders.Date = utcNow - TimeSpan.FromSeconds(10);
+            Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
+
+            // Verify modifications at present succeeds
+            cachedHeaders.Date = utcNow;
+            Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
+
+            // Verify modifications in the future fails
+            cachedHeaders.Date = utcNow + TimeSpan.FromSeconds(10);
+            Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
+        }
+
+        [Fact]
+        public void ConditionalRequestSatisfied_IfUnmodifiedSince_LastModifiedOverridesDateHeader()
+        {
+            var utcNow = DateTimeOffset.UtcNow;
+            var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
+            var httpContext = new DefaultHttpContext();
+            var context = CreateTestContext(httpContext);
+
+            httpContext.Request.GetTypedHeaders().IfUnmodifiedSince = utcNow;
+
+            // Verify modifications in the past succeeds
+            cachedHeaders.Date = utcNow + TimeSpan.FromSeconds(10);
+            cachedHeaders.LastModified = utcNow - TimeSpan.FromSeconds(10);
+            Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
+
+            // Verify modifications at present
+            cachedHeaders.Date = utcNow + TimeSpan.FromSeconds(10);
+            cachedHeaders.LastModified = utcNow;
+            Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
+
+            // Verify modifications in the future fails
+            cachedHeaders.Date = utcNow - TimeSpan.FromSeconds(10);
+            cachedHeaders.LastModified = utcNow + TimeSpan.FromSeconds(10);
+            Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
+        }
+
+        [Fact]
+        public void ConditionalRequestSatisfied_IfNoneMatch_Overrides_IfUnmodifiedSince_ToPass()
+        {
+            var utcNow = DateTimeOffset.UtcNow;
+            var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
+            var httpContext = new DefaultHttpContext();
+            var requestHeaders = httpContext.Request.GetTypedHeaders();
+            var context = CreateTestContext(httpContext);
+
+            // This would fail the IfUnmodifiedSince checks
+            requestHeaders.IfUnmodifiedSince = utcNow;
+            cachedHeaders.LastModified = utcNow + TimeSpan.FromSeconds(10);
+
+            requestHeaders.IfNoneMatch = new List<EntityTagHeaderValue>(new[] { EntityTagHeaderValue.Any });
+            Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
+        }
+
+        [Fact]
+        public void ConditionalRequestSatisfied_IfNoneMatch_Overrides_IfUnmodifiedSince_ToFail()
+        {
+            var utcNow = DateTimeOffset.UtcNow;
+            var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
+            var httpContext = new DefaultHttpContext();
+            var requestHeaders = httpContext.Request.GetTypedHeaders();
+            var context = CreateTestContext(httpContext);
+
+            // This would pass the IfUnmodifiedSince checks
+            requestHeaders.IfUnmodifiedSince = utcNow;
+            cachedHeaders.LastModified = utcNow - TimeSpan.FromSeconds(10);
+
+            requestHeaders.IfNoneMatch = new List<EntityTagHeaderValue>(new[] { new EntityTagHeaderValue("\"E1\"") });
+            Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
+        }
+
+        [Fact]
+        public void ConditionalRequestSatisfied_IfNoneMatch_AnyWithoutETagInResponse_Passes()
+        {
+            var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
+            var httpContext = new DefaultHttpContext();
+            var context = CreateTestContext(httpContext);
+
+            httpContext.Request.GetTypedHeaders().IfNoneMatch = new List<EntityTagHeaderValue>(new[] { new EntityTagHeaderValue("\"E1\"") });
+
+            Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
+        }
+
+        [Fact]
+        public void ConditionalRequestSatisfied_IfNoneMatch_ExplicitWithMatch_Passes()
+        {
+            var cachedHeaders = new ResponseHeaders(new HeaderDictionary())
+            {
+                ETag = new EntityTagHeaderValue("\"E1\"")
+            };
+            var httpContext = new DefaultHttpContext();
+            var context = CreateTestContext(httpContext);
+
+            httpContext.Request.GetTypedHeaders().IfNoneMatch = new List<EntityTagHeaderValue>(new[] { new EntityTagHeaderValue("\"E1\"") });
+
+            Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
+        }
+
+        [Fact]
+        public void ConditionalRequestSatisfied_IfNoneMatch_ExplicitWithoutMatch_Fails()
+        {
+            var cachedHeaders = new ResponseHeaders(new HeaderDictionary())
+            {
+                ETag = new EntityTagHeaderValue("\"E2\"")
+            };
+            var httpContext = new DefaultHttpContext();
+            var context = CreateTestContext(httpContext);
+
+            httpContext.Request.GetTypedHeaders().IfNoneMatch = new List<EntityTagHeaderValue>(new[] { new EntityTagHeaderValue("\"E1\"") });
+
+            Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
+        }
+
         private static ResponseCachingContext CreateTestContext(HttpContext httpContext)
         {
             return CreateTestContext(