Implement enum parsing

Signed-off-by: Thomas Farr <[email protected]>
opensearch-project · Sep 20, 2024 · 04c7c83 · 04c7c83
1 parent 4a39935
commit 04c7c83
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Showing 2 changed files with 32 additions and 4 deletions.
diff --git a/src/OpenSearch.Net/Api/Enums.cs b/src/OpenSearch.Net/Api/Enums.cs
@@ -55,6 +55,7 @@ namespace OpenSearch.Net
 	public static partial class KnownEnums
 	{
 		private static readonly ConcurrentDictionary<Type, Func<Enum, string>> EnumStringResolvers = new();
+        private static readonly ConcurrentDictionary<Type, Func<string, Enum>> EnumStringParsers = new();
 
 		static KnownEnums() => RegisterEnumStringResolvers();
 
@@ -84,9 +85,36 @@ private static Func<Enum, string> GetEnumStringResolver(Type type)
 			}
 
 			var isFlag = type.GetCustomAttributes(typeof(FlagsAttribute), false).Length > 0;
-			return e => !isFlag
-				? dictionary[e]
-				: string.Join(",", dictionary.Where(kv => e.HasFlag(kv.Key)).Select(kv => kv.Value));
+            return isFlag
+                ? e => string.Join(",", dictionary.Where(kv => e.HasFlag(kv.Key)).Select(kv => kv.Value))
+                : e => dictionary[e];
 		}
+
+        public static TEnum Parse<TEnum>(string value)
+            where TEnum : struct, Enum
+        {
+            var parser = EnumStringParsers.GetOrAdd(typeof(TEnum), GetEnumStringParser);
+            return (TEnum) parser(value);
+        }
+
+        private static Func<string, Enum> GetEnumStringParser(Type type)
+        {
+            var values = Enum.GetValues(type);
+            var dictionary = new Dictionary<string, Enum>(values.Length);
+            for (var index = 0; index < values.Length; index++)
+            {
+                var value = values.GetValue(index);
+                var info = type.GetField(value.ToString());
+                var da = (EnumMemberAttribute[])info.GetCustomAttributes(typeof(EnumMemberAttribute), false);
+                var stringValue = da.Length > 0 ? da[0].Value : Enum.GetName(type, value)!;
+                dictionary.Add(stringValue.ToLowerInvariant(), (Enum)value);
+            }
+
+            var isFlag = type.GetCustomAttributes(typeof(FlagsAttribute), false).Length > 0;
+
+            return isFlag
+                ? s => (Enum) Convert.ChangeType(s.ToLowerInvariant().Split(',').Aggregate(0ul, (acc, value) => acc | Convert.ToUInt64(dictionary[value])), type)
+                : s => dictionary[s.ToLowerInvariant()];
+        }
 	}
 }
diff --git a/tests/Tests.YamlRunner/DoMapper.fs b/tests/Tests.YamlRunner/DoMapper.fs
@@ -89,7 +89,7 @@ type FastApiInvoke(instance: Object, restName:string, pathParams:KeyedCollection
             let underlyingType = Nullable.GetUnderlyingType(t)
             if v = null then null
             else this.ArgConvert(v, underlyingType)
-        | t when t.IsEnum -> Enum.Parse(t, this.ArgString v, true)
+        | t when t.IsEnum -> typeof<KnownEnums>.GetMethod("Parse").MakeGenericMethod(t).Invoke(null, [|v|])
         | t -> failwithf $"unable to convert argument to type %s{t.FullName}"
 
     member this.ArgString (v:Object): string =