Add native support for DisplayAttribute.Description with EnumFormat.DisplayDescription

Src/Enums.NET.Test/EnumsTest.cs

@@ -761,6 +761,11 @@ public void AsString_ReturnsValidResult_WhenUsingValidEnumFormat()
         AssertTryFormat(DisplayAttributeEnum.Left, "Izquierda", EnumFormat.DisplayName);
         AssertTryFormat(DisplayAttributeEnum.Right, "Derecho", EnumFormat.DisplayName);
 
+        AssertTryFormat(CardinalDirection.North, "N", EnumFormat.DisplayDescription);
+        AssertTryFormat(CardinalDirection.South, "S", EnumFormat.DisplayDescription);
+        AssertTryFormat(CardinalDirection.East, "E", EnumFormat.DisplayDescription);
+        AssertTryFormat(CardinalDirection.West, "W", EnumFormat.DisplayDescription);
+
         AssertTryFormat(ToObject<CharEnum>('a'), "a", EnumFormat.UnderlyingValue);
         AssertTryFormat(ToObject<CharEnum>('a'), ((ushort)'a').ToString(), EnumFormat.DecimalValue);
         AssertTryFormat(ToObject<CharEnum>('a'), ((ushort)'a').ToString("X4"), EnumFormat.HexadecimalValue);

Src/Enums.NET.TestEnums/CardinalDirection.cs

@@ -0,0 +1,15 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace EnumsNET.Tests.TestEnums;
+
+public enum CardinalDirection
+{
+    [Display(Description = "N")]
+    North,
+    [Display(Description = "S")]
+    South,
+    [Display(Description = "E")]
+    East,
+    [Display(Description = "W")]
+    West
+}

Src/Enums.NET/EnumCache.cs

@@ -727,6 +727,7 @@ public string AsString(TUnderlying value)
         EnumFormat.Description => GetMember(value)?.Attributes.Get<DescriptionAttribute>()?.Description,
         EnumFormat.EnumMemberValue => GetMember(value)?.Attributes.Get<EnumMemberAttribute>()?.Value,
         EnumFormat.DisplayName => GetMember(value)?.Attributes.Get<DisplayAttribute>()?.GetName(),
+        EnumFormat.DisplayDescription => GetMember(value)?.Attributes.Get<DisplayAttribute>()?.GetDescription(),
         _ => Enums.CustomEnumMemberFormat(GetMember(value)?.EnumMember, format.Validate(nameof(format)))
     };
 
@@ -762,6 +763,7 @@ internal string AsStringInternal(TUnderlying value, EnumMemberInternal<TUnderlyi
         EnumFormat.Description => TryInitializeMember(value, ref isInitialized, ref member)?.Attributes.Get<DescriptionAttribute>()?.Description,
         EnumFormat.EnumMemberValue => TryInitializeMember(value, ref isInitialized, ref member)?.Attributes.Get<EnumMemberAttribute>()?.Value,
         EnumFormat.DisplayName => TryInitializeMember(value, ref isInitialized, ref member)?.Attributes.Get<DisplayAttribute>()?.GetName(),
+        EnumFormat.DisplayDescription => TryInitializeMember(value, ref isInitialized, ref member)?.Attributes.Get<DisplayAttribute>()?.GetDescription(),
         _ => Enums.CustomEnumMemberFormat(TryInitializeMember(value, ref isInitialized, ref member)?.EnumMember, format.Validate(nameof(format)))
     };
 
@@ -868,6 +870,9 @@ internal bool TryFormatInternal(TUnderlying value, EnumMemberInternal<TUnderlyin
             case EnumFormat.DisplayName:
                 var displayName = TryInitializeMember(value, ref isInitialized, ref member)?.Attributes.Get<DisplayAttribute>()?.GetName();
                 return TryWriteStringToSpan(displayName, destination, out charsWritten);
+            case EnumFormat.DisplayDescription:
+                var displayDescription = TryInitializeMember(value, ref isInitialized, ref member)?.Attributes.Get<DisplayAttribute>()?.GetDescription();
+                return TryWriteStringToSpan(displayDescription, destination, out charsWritten);
             default:
                 var v = Enums.CustomEnumMemberFormat(TryInitializeMember(value, ref isInitialized, ref member)?.EnumMember, format.Validate(nameof(format)));
                 return TryWriteStringToSpan(v, destination, out charsWritten);

Src/Enums.NET/EnumFormat.cs

@@ -63,7 +63,11 @@ public enum EnumFormat
     /// <summary>
     /// Enum is represented by its <see cref="DisplayAttribute.Name"/>.
     /// </summary>
-    DisplayName = 6
+    DisplayName = 6,
+    /// <summary>
+    /// Enum is represented by its <see cref="DisplayAttribute.Description"/>.
+    /// </summary>
+    DisplayDescription = 7
 }
 
 [AttributeUsage(AttributeTargets.Enum)]

Src/Enums.NET/Enums.cs

@@ -190,7 +190,7 @@ internal static ValueCollection<EnumFormat> NameFormat
     }
 
     #region Custom EnumFormat
-    private const int s_startingCustomEnumFormatValue = (int)EnumFormat.DisplayName + 1;
+    private const int s_startingCustomEnumFormatValue = (int)EnumFormat.DisplayDescription + 1;
 
     private static Func<EnumMember, string?>[] s_customEnumMemberFormatters = [];