Tests for GetHttpProtocolVersion (#14477)

src/Shared/test/Shared.Tests/HttpSysGetHttpProtocolVersionTest.cs

@@ -0,0 +1,29 @@
+// 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 Xunit;
+
+namespace Microsoft.AspNetCore.HttpSys.Internal
+{
+    public class HttpSysGetHttpProtocolVersionTest
+    {
+        public static TheoryData<Version, string> s_data = new TheoryData<Version, string>
+        {
+            { new Version(2, 0), "HTTP/2" },
+            { new Version(1, 1), "HTTP/1.1" },
+            { new Version(1, 0), "HTTP/1.0" },
+            { new Version(0, 3), "HTTP/0.3" },
+            { new Version(2, 1), "HTTP/2.1" }
+        };
+
+        [Theory]
+        [MemberData(nameof(s_data))]
+        public void GetHttpProtocolVersion_CorrectIETFVersion(Version version, string expected)
+        {
+            var actual = version.GetHttpProtocolVersion();
+
+            Assert.Equal(expected, actual);
+        }
+    }
+}