UTY-1970: invalid enum definition

CHANGELOG.md

@@ -10,6 +10,11 @@
 - Added support for flag arguments in `CommandLineParser`. [#1409](https://github.com/spatialos/gdk-for-unity/pull/1409)
 - Added `Scripting Backend` option dropdown to the Build Configuration UI. [#1411](https://github.com/spatialos/gdk-for-unity/pull/1411)
 
+### Breaking Changes
+
+- All generated C# enums will now start from 0, being shifted to schema values on serialization and shifted back to C# values on deserialization. [#1412](https://github.com/spatialos/gdk-for-unity/pull/1412)
+    - A warning will be generated when enums defined in schema does not start from 0. 
+
 ### Changed
 
 - Moved Gdk Tools Configuration to the Unity "Project Settings" window under `Spatial OS`. [#1408](https://github.com/spatialos/gdk-for-unity/pull/1408)

workers/unity/Packages/io.improbable.gdk.tools/.CodeGenTemplate/CodeGenerationLib/Model/Details/FieldTypes/ContainedType.cs

@@ -44,7 +44,8 @@ public string GetSerializationStatement(string instance, string schemaObject, ui
                 case ValueType.Primitive:
                     return $"{schemaObject}.{SchemaFunctionMappings.AddSchemaFunctionFromType(PrimitiveType.Value)}({fieldNumber}, {instance});";
                 case ValueType.Enum:
-                    return $"{schemaObject}.AddEnum({fieldNumber}, (uint) {instance});";
+                    var shifter = UnityEnumDetails.GetEnumMinimum(FqnType);
+                    return $"{schemaObject}.AddEnum({fieldNumber}, (uint) ({instance}) + {shifter});";
                 case ValueType.Type:
                     return $"{FqnType}.Serialization.Serialize({instance}, {schemaObject}.AddObject({fieldNumber}));";
                 default:
@@ -60,7 +61,8 @@ public string GetDeserializationExpression(string schemaObject, uint fieldNumber
                     return
                         $"{schemaObject}.{SchemaFunctionMappings.GetSchemaFunctionFromType(PrimitiveType.Value)}({fieldNumber})";
                 case ValueType.Enum:
-                    return $"({FqnType}) {schemaObject}.GetEnum({fieldNumber})";
+                    var shifter = UnityEnumDetails.GetEnumMinimum(FqnType);
+                    return $"({FqnType}) ({schemaObject}.GetEnum({fieldNumber}) - {shifter})";
                 case ValueType.Type:
                     return $"{FqnType}.Serialization.Deserialize({schemaObject}.GetObject({fieldNumber}))";
                 default:

workers/unity/Packages/io.improbable.gdk.tools/.CodeGenTemplate/CodeGenerationLib/Model/Details/TypeDetails/UnityEnumDetails.cs

@@ -1,16 +1,41 @@
+using System;
 using System.Collections.Generic;
 using System.Linq;
+using NLog;
 
 namespace Improbable.Gdk.CodeGeneration.Model.Details
 {
     public class UnityEnumDetails : GeneratorInputDetails
     {
         public readonly IReadOnlyList<(uint, string)> Values;
 
+        private static readonly Dictionary<string, uint> EnumMinimums = new Dictionary<string, uint>();
+
+        private static readonly Logger Logger = LogManager.GetCurrentClassLogger();
+
         public UnityEnumDetails(string package, EnumDefinition rawEnumDefinition)
             : base(package, rawEnumDefinition)
         {
-            Values = rawEnumDefinition.Values.Select(value => (value.Value, value.Name)).ToList();
+            var min = rawEnumDefinition.Values.Select(list => list.Value).Min();
+            EnumMinimums[FullyQualifiedName] = min;
+            if (min != 0)
+            {
+                Logger.Warn($"The enum, {Name}, is defined with a minimum value of {min}, which is greater than 0. Shifting the enum values to start from 0. " +
+                    "This will lead to inconsistencies in the values used in Unity and the values captured in snapshots. " +
+                    $"This inconsistency is handled in the serialization/deserialization process but please consider redefining the values in {Name} to start from 0");
+            }
+
+            Values = rawEnumDefinition.Values.Select(value => (value.Value - min, value.Name)).ToList();
+        }
+
+        public static uint GetEnumMinimum(string fullQualifiedName)
+        {
+            if (!EnumMinimums.TryGetValue(fullQualifiedName, out var output))
+            {
+                throw new ArgumentException($"Could not find the following enum: {fullQualifiedName}");
+            }
+
+            return output;
         }
     }
 }