Fix code-generation on enumerations

Tests/Tests.Asn1SourceGenerator/EmitterTests.cs

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Collections.Generic;
@@ -326,6 +326,34 @@ public void Emit_InlineSequenceOfField_GeneratesArrayProperty()
             Assert.IsTrue(code.Contains("int[]"), "Inline SEQUENCE OF INTEGER should produce int[]");
         }
 
+        // ─── Enumerated field ────────────────────────────────
+        [TestMethod]
+        public void Emit_EnumeratedDecode_UsesEnumReaderOrIntFallback()
+        {
+            var code = EmitSingle(@"
+-- @cs-class: KrbEnumDecode
+EnumDecode ::= SEQUENCE {
+    typed-state [0] ENUMERATED { a(0), b(1) }, -- @cs-name: TypedState @cs-enum: MyState
+    raw-state   [1] ENUMERATED { c(0), d(1) }  -- @cs-name: RawState
+}");
+
+            // Branch: EnumType is set
+            Assert.IsTrue(
+                code.Contains("ReadEnumeratedValue<MyState>()"),
+                "ENUMERATED with @cs-enum should use ReadEnumeratedValue<TEnum>().");
+
+            // Branch: EnumType is not set
+            Assert.IsTrue(
+                code.Contains("TryReadInt32(out int tmpRawState)"),
+                "ENUMERATED without @cs-enum should use TryReadInt32 fallback.");
+            Assert.IsTrue(
+                code.Contains("ThrowIfNotEmpty();"),
+                "TryReadInt32 fallback should include ThrowIfNotEmpty guard.");
+            Assert.IsTrue(
+                code.Contains("decoded.RawState = tmpRawState;"),
+                "TryReadInt32 fallback should assign temp value to decoded property.");
+        }
+
         // ─── Full pipeline smoke test with real schema snippet ──────
 
         [TestMethod]

Tools/Asn1SourceGenerator/Emit/CSharpEmitter.cs

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
@@ -1138,17 +1138,17 @@ private static void EmitFieldValueDecode(IndentedWriter w, ResolvedField field,
 
                 case FieldKind.Enumerated:
                     w.WriteLine();
-                    w.WriteLine($"if (!{readerVar}.TryReadInt32(out int tmp{field.PropertyName}))");
-                    w.OpenBrace();
-                    w.WriteLine($"{readerVar}.ThrowIfNotEmpty();");
-                    w.CloseBrace();
-                    w.WriteLine();
+
                     if (!string.IsNullOrEmpty(field.Encoding.EnumType))
                     {
-                        w.WriteLine($"decoded.{field.PropertyName} = ({field.Encoding.EnumType})tmp{field.PropertyName};");
+                        w.WriteLine($"decoded.{field.PropertyName} = {readerVar}.ReadEnumeratedValue<{field.Encoding.EnumType}>();");
                     }
                     else
                     {
+                        w.WriteLine($"if (!{readerVar}.TryReadInt32(out int tmp{field.PropertyName}))");
+                        w.OpenBrace();
+                        w.WriteLine($"{readerVar}.ThrowIfNotEmpty();");
+                        w.CloseBrace();
                         w.WriteLine($"decoded.{field.PropertyName} = tmp{field.PropertyName};");
                     }
                     break;