use Enum.TryParse<TEnum>

Author: lbargaoanu

src/AutoMapper/Mappers/EnumToEnumMapper.cs

@@ -14,10 +14,14 @@ public Expression MapExpression(IGlobalConfiguration configurationProvider, Prof
         {
             var destinationType = destExpression.Type;
             var sourceToString = Call(sourceExpression, ObjectToString);
+            var (tryParse, result) = TryParse(destinationType, sourceToString);
+            return Block(new[] { result }, Condition(tryParse, result, Convert(sourceExpression, destinationType)));
+        }
+        internal static (MethodCallExpression TryParse, ParameterExpression Result) TryParse(Type destinationType, Expression value)
+        {
             var result = Variable(destinationType, "destinationEnumValue");
             var ignoreCase = True;
-            var tryParse = Call(TryParseMethod.MakeGenericMethod(destinationType), sourceToString, ignoreCase, result);
-            return Block(new[] { result }, Condition(tryParse, result, Convert(sourceExpression, destinationType)));
+            return (Call(TryParseMethod.MakeGenericMethod(destinationType), value, ignoreCase, result), result);
         }
     }
 }

src/AutoMapper/Mappers/StringToEnumMapper.cs

@@ -9,9 +9,7 @@ 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));
         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 +27,9 @@ public Expression MapExpression(IGlobalConfiguration configurationProvider, Prof
                     switchCases.Add(switchCase);
                 }
             }
-            var enumParse = ToType(Call(ParseMethod, Constant(destinationType), sourceExpression, True), destinationType);
-            var parse = switchCases != null ? Switch(sourceExpression, enumParse, EqualsMethod, switchCases) : enumParse;
-            return Condition(Call(IsNullOrEmptyMethod, sourceExpression), Default(destinationType), parse);
+            var (tryParse, result) = EnumToEnumMapper.TryParse(destinationType, sourceExpression);
+            var returnValue = switchCases != null ? Switch(sourceExpression, result, EqualsMethod, switchCases) : (Expression)result;
+            return Block(new[] { result }, tryParse, returnValue);
         }
         public static bool StringCompareOrdinalIgnoreCase(string x, string y) => StringComparer.OrdinalIgnoreCase.Equals(x, y);
     }