fix spacing, add back s3 integ test and precompile regex for sanitization

Author: peterrsongg

sdk/src/Core/Amazon.Runtime/Internal/Transform/JsonUnmarshallerContext.cs

@@ -281,7 +281,7 @@ public string ReadText(ref StreamingUtf8JsonReader reader)
                     // overload which accepts a ReadOnlySpan<byte> is only available in netstandard2.1 and netcore2.1+
                     text = Encoding.UTF8.GetString(reader.Reader.ValueSpan.ToArray());
 #else
-                                    text = Encoding.UTF8.GetString(reader.Reader.ValueSpan);
+                    text = Encoding.UTF8.GetString(reader.Reader.ValueSpan);
 #endif
                     break;
                 default:

sdk/src/Core/Amazon.Util/Internal/JsonSerializerHelper.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Text;
+using System.Text.RegularExpressions;
 using System.Text.Json;
 
 #if NET8_0_OR_GREATER
@@ -16,6 +17,9 @@ public static class JsonSerializerHelper
         {
             AllowTrailingCommas = true,
         };
+
+        // compile regex once to avoid re-parsing every time
+        private static readonly System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex(@"(""[^""]*""|\d+)(\s*""[^""]*""\s*:)", System.Text.RegularExpressions.RegexOptions.Compiled);
 #if NET8_0_OR_GREATER
         public static T Deserialize<T>(string json, JsonSerializerContext context)
         {
@@ -46,7 +50,7 @@ public static string Serialize<T>(object obj, JsonSerializerContext typeInfo)
         public static string SanitizeJson(string rawJson)
         {
             // Add a comma after numbers or strings if they're not followed by a closing brace/bracket or comma.
-            rawJson = System.Text.RegularExpressions.Regex.Replace(rawJson, @"(""[^""]*""|\d+)(\s*""[^""]*""\s*:)", "$1,$2");
+            rawJson = regex.Replace(rawJson, "$1,$2");
             return rawJson;
         }
     }

sdk/test/Services/S3/IntegrationTests/S3ExpressTests.cs

@@ -212,7 +212,6 @@ public void Test_CopyObject_BetweenS3ExpressBuckets()
 
         [TestMethod]
         [TestCategory("S3")]
-        [Ignore]
         public void Test_CopyObject_BetweenRegularBucket_And_S3ExpressBucket()
         {
             var oldObjectKey = "Test Object 123";

sdk/test/UnitTests/Custom/Runtime/EC2InstanceMetadataServlet.cs

@@ -30,30 +30,10 @@ public EC2InstanceMetadataServlet()
                 new DisposableSwitch(
                     onStart: () => SetEC2InstanceMetadataEndpoint(ServiceURL),
                     onEnd: () => SetEC2InstanceMetadataEndpoint(currentEndpointUrl));
-
-            // JsonMapper.ToJson's DateTime writing exporter will output any date as a string formatted
-            // as a local or unspecified time. This changes it so the data is mocked as IMDS would
-            // actually return it which is "yyyy-MM-ddTHH:mm:ssZ" ending in a Z specified as UTC.
-            //JsonMapper.RegisterExporter<DateTime>(
-            //    (DateTime date, JsonWriter writer) => {                     
-            //        if(date == DateTime.MinValue && date.Kind != DateTimeKind.Utc)
-            //        {
-            //            //Do not use .ToUniversalTime on a min datetime as it will adjust the hours.
-            //            DateTime.SpecifyKind(date, DateTimeKind.Utc);
-            //        }
-            //        else if(date.Kind != DateTimeKind.Utc)
-            //        {
-            //            date = date.ToUniversalTime();
-            //        }
-
-            //        writer.Write(date.ToString("yyyy-MM-ddTHH:mm:ssZ"));
-            //    }
-            //);
         }
 
         public override void Dispose()
         {
-            //JsonMapper.UnregisterExporters();
             _metadataServiceEndpointSwitch.Dispose();
 
             ResetUseNullToken();

sdk/test/UnitTests/Custom/Runtime/_bcl/Tokens/SSOTokenManagerTests.cs

@@ -60,7 +60,6 @@ public void ValidateTokenCacheLocation(string startUrl, string expectedCacheFile
                 accessToken = "cachedToken",
                 expiresAt = "3000-12-25T21:30:00Z",
             };
-            
             mockFileSystem.WriteAllText(
                 Path.Combine(testCacheFolder, expectedCacheFile),
                 JsonSerializer.Serialize(cachedSsoToken));

sdk/test/UnitTests/Custom/TestTools/SpecMarkdownTestDataHelper.cs

@@ -5,7 +5,6 @@
 namespace AWSSDK.UnitTests
 {
     public static class SpecMarkdownTestDataHelper
-
     {
         public static string StandardDataClean(this string s)
         {