use Enum.Parse<TEnum>

Author: lbargaoanu

src/AutoMapper/Mappers/StringToEnumMapper.cs

@@ -9,9 +9,9 @@ namespace AutoMapper.Internal.Mappers
     using static Expression;
     public class StringToEnumMapper : IObjectMapper
     {
-        private static readonly MethodInfo EqualsMethod = typeof(StringToEnumMapper).GetMethod("StringCompareOrdinalIgnoreCase");
-        private static readonly MethodInfo ParseMethod = typeof(Enum).GetMethod("Parse", new[] { typeof(Type), typeof(string), typeof(bool) });
-        private static readonly MethodInfo IsNullOrEmptyMethod = typeof(string).GetMethod("IsNullOrEmpty");
+        private static readonly MethodInfo EqualsMethod = typeof(StringToEnumMapper).GetMethod(nameof(StringCompareOrdinalIgnoreCase));
+        private static readonly MethodInfo ParseMethod = typeof(Enum).StaticGenericMethod("Parse", parametersCount: 2);
+        private static readonly PropertyInfo LengthProperty = typeof(string).GetProperty("Length");
         public bool IsMatch(TypePair context) => context.SourceType == typeof(string) && context.DestinationType.IsEnum;
         public Expression MapExpression(IGlobalConfiguration configurationProvider, ProfileMap profileMap,
             MemberMap memberMap, Expression sourceExpression, Expression destExpression)
@@ -29,9 +29,10 @@ public Expression MapExpression(IGlobalConfiguration configurationProvider, Prof
                     switchCases.Add(switchCase);
                 }
             }
-            var enumParse = ToType(Call(ParseMethod, Constant(destinationType), sourceExpression, True), destinationType);
+            var ignoreCase = True;
+            Expression enumParse = Call(ParseMethod.MakeGenericMethod(destinationType), sourceExpression, ignoreCase);
             var parse = switchCases != null ? Switch(sourceExpression, enumParse, EqualsMethod, switchCases) : enumParse;
-            return Condition(Call(IsNullOrEmptyMethod, sourceExpression), Default(destinationType), parse);
+            return Condition(Equal(Property(sourceExpression, LengthProperty), Zero), Default(destinationType), parse);
         }
         public static bool StringCompareOrdinalIgnoreCase(string x, string y) => StringComparer.OrdinalIgnoreCase.Equals(x, y);
     }