Fix codegen so that we can generate samples for MySql properly

src/AutoRest.CSharp/Common/Utilities/StringExtensions.cs

@@ -6,7 +6,6 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Text;
-using System.Text.RegularExpressions;
 using AutoRest.CSharp.Input;
 using AutoRest.CSharp.Mgmt.Models;
 using Humanizer;
@@ -56,6 +55,9 @@ public static string ToCleanName(this string name, bool isCamelCase = true)
                 var c = name[i];
                 if (IsWordSeparator(c))
                 {
+                    // keep following _ if there are multiple _ in a row, so that we can have a way to customize name with _
+                    if (name[i] == '_' && i > 0 && name[i - 1] == '_')
+                        nameBuilder.Append(c);
                     upperCase = true;
                     continue;
                 }

src/AutoRest.CSharp/Mgmt/AutoRest/MgmtOutputLibrary.cs

@@ -747,6 +747,13 @@ public override TypeProvider FindTypeProviderForSchema(Schema schema)
         public override CSharpType? FindTypeByName(string originalName)
         {
             _schemaOrNameToModels.TryGetValue(originalName, out TypeProvider? provider);
+
+            if (provider == null)
+            {
+                // Try to search declaration name too if no key matches. i.e. Resource Data Type will be appended a 'Data' in the name and won't be found through key
+                provider = _schemaOrNameToModels.FirstOrDefault(s => s.Value is MgmtObjectType mot && mot.Declaration.Name == originalName).Value;
+            }
+
             provider ??= ResourceSchemaMap.Values.FirstOrDefault(m => m.Type.Name == originalName);
             return provider?.Type;
         }

src/AutoRest.CSharp/MgmtTest/Extensions/CodeWriterExtensions.cs

@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Net;
+using System.Transactions;
 using System.Xml;
 using AutoRest.CSharp.Generation.Types;
 using AutoRest.CSharp.Generation.Writers;
@@ -151,8 +152,18 @@ private static CodeWriter AppendComplexFrameworkTypeValue(this CodeWriter writer
             writer.Append($"new {type}(");
             foreach (var parameter in publicCtor.GetParameters())
             {
-                // we here assume the parameter name is the same as the serialized name of the property. This is not 100% solid
-                var value = exampleValue.Properties[parameter.Name!];
+                ExampleValue value;
+                if (exampleValue.Properties.ContainsKey(parameter.Name!))
+                    // we here assume the parameter name is the same as the serialized name of the property. This is not 100% solid
+                    value = exampleValue.Properties[parameter.Name!];
+                else
+                {
+                    // if we can't find it directly, try to figure out the serailizedName form propertyMetadataDict
+                    string? serializedName = propertyMetadataDict.FirstOrDefault(p => string.Equals(p.Key, parameter.Name!, StringComparison.OrdinalIgnoreCase)).Value?.SerializedName;
+                    if (string.IsNullOrEmpty(serializedName) || !exampleValue.Properties.ContainsKey(serializedName))
+                        throw new InvalidOperationException($"Unabled to find example value for ctor parameter, type={type.FullName}, param={parameter.Name ?? "<null>"}");
+                    value = exampleValue.Properties[serializedName];
+                }
                 writer.AppendExampleValue(value, parameter.ParameterType);
                 writer.AppendRaw(",");
             }