Fix Default value (#19)

src/ProxyInterfaceSourceGenerator/Extensions/ParameterSymbolExtensions.cs

@@ -0,0 +1,35 @@
+using Microsoft.CodeAnalysis;
+using ProxyInterfaceSourceGenerator.Enums;
+
+namespace ProxyInterfaceSourceGenerator.Extensions
+{
+    internal static class ParameterSymbolExtensions
+    {
+        public static string GetRefPrefix(this IParameterSymbol ps)
+        {
+            switch (ps.RefKind)
+            {
+                case RefKind.In:
+                    return "in ";
+
+                case RefKind.Out:
+                    return "out ";
+
+                case RefKind.Ref:
+                    return "ref ";
+
+                default:
+                    return string.Empty;
+            }
+        }
+
+        public static string GetParamsPrefix(this IParameterSymbol ps) =>
+            ps.IsParams ? "params " : string.Empty;
+
+        public static string GetDefaultValue(this IParameterSymbol ps) =>
+            ps.HasExplicitDefaultValue ? $" = {ps.ExplicitDefaultValue}" : string.Empty;
+
+        public static TypeEnum GetTypeEnum(this IParameterSymbol p) =>
+            p.Type.GetTypeEnum();
+    }
+}