From 415d9ed9232e8a837e535aba2a5a1deaee4d1487 Mon Sep 17 00:00:00 2001
From: Robert Wagner <robert@wagner.id.au>
Date: Tue, 15 Sep 2020 10:17:15 +1000
Subject: [PATCH] Added support for nullable value types and enums

---
 .../Converters/EnumAttributeOclConverter.cs   | 32 +++++++++++++++++
 source/Ocl/OclAttribute.cs                    |  9 ++++-
 source/Ocl/OclConversionContext.cs            |  1 +
 .../FromOclDocumentDefaultBehaviourFixture.cs | 35 ++++++++++++++++++-
 .../ToOclBodyDefaultBehaviourFixture.cs       | 17 +++++++++
 5 files changed, 92 insertions(+), 2 deletions(-)
 create mode 100644 source/Ocl/Converters/EnumAttributeOclConverter.cs

diff --git a/source/Ocl/Converters/EnumAttributeOclConverter.cs b/source/Ocl/Converters/EnumAttributeOclConverter.cs
new file mode 100644
index 0000000..67d530c
--- /dev/null
+++ b/source/Ocl/Converters/EnumAttributeOclConverter.cs
@@ -0,0 +1,32 @@
+using System;
+
+namespace Octopus.Ocl.Converters
+{
+    public class EnumAttributeOclConverter : OclConverter
+    {
+        public override bool CanConvert(Type type)
+            => type.IsEnum;
+
+        public override object? FromElement(OclConversionContext context, Type type, IOclElement element, Func<object?> getCurrentValue)
+        {
+            if (element is OclAttribute attribute)
+            {
+                if (attribute.Value == null)
+                    return null;
+
+                if (attribute.Value is string str)
+                    return Enum.Parse(type, str);
+
+                if (attribute.Value is OclStringLiteral strLit)
+                    return Enum.Parse(type, strLit.Value);
+
+                throw new Exception("Enum values must be specified as a string");
+            }
+
+            throw new OclException("Can only convert attribute elements");
+        }
+
+        protected override IOclElement ConvertInternal(OclConversionContext context, string name, object obj)
+            => new OclAttribute(GetName(name, obj), obj.ToString());
+    }
+}
\ No newline at end of file
diff --git a/source/Ocl/OclAttribute.cs b/source/Ocl/OclAttribute.cs
index 1dc9c44..f7bc2fc 100644
--- a/source/Ocl/OclAttribute.cs
+++ b/source/Ocl/OclAttribute.cs
@@ -50,11 +50,18 @@ public object? Value
         }
 
         public static bool IsSupportedValueType(Type type)
-            => type.IsPrimitive ||
+        {
+            bool IsNullableSupportedValueType()
+                => type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>) && IsSupportedValueType(type.GetGenericArguments()[0]);
+
+            return type.IsPrimitive ||
                 type == typeof(string) ||
                 type == typeof(decimal) ||
                 type == typeof(OclStringLiteral) ||
+                IsNullableSupportedValueType() ||
                 IsSupportedValueCollectionType(type);
+        }
+
 
         internal static bool IsSupportedValueCollectionType(Type type)
             => (type.IsArray && type.GetArrayRank() == 1 && IsSupportedValueType(type.GetElementType()!)) ||
diff --git a/source/Ocl/OclConversionContext.cs b/source/Ocl/OclConversionContext.cs
index bc8a895..814a4f4 100644
--- a/source/Ocl/OclConversionContext.cs
+++ b/source/Ocl/OclConversionContext.cs
@@ -16,6 +16,7 @@ internal OclConversionContext(OclSerializerOptions options)
                 .Concat(
                     new IOclConverter[]
                     {
+                        new EnumAttributeOclConverter(),
                         new DefaultAttributeOclConverter(),
                         new DefaultCollectionOclConverter(),
                         new DefaultBlockOclConverter(),
diff --git a/source/Tests/FromOclDoc/FromOclDocumentDefaultBehaviourFixture.cs b/source/Tests/FromOclDoc/FromOclDocumentDefaultBehaviourFixture.cs
index b13c584..487ca1d 100644
--- a/source/Tests/FromOclDoc/FromOclDocumentDefaultBehaviourFixture.cs
+++ b/source/Tests/FromOclDoc/FromOclDocumentDefaultBehaviourFixture.cs
@@ -29,6 +29,19 @@ public void IntAttribute()
                 .BeEquivalentTo(new Car() { Doors = 4 });
         }
 
+        [Test]
+        public void IntNullAttribute()
+        {
+            var document = new OclDocument()
+            {
+                new OclAttribute("Doors", null)
+            };
+
+            OclConvert.Deserialize<Car>(document, new OclSerializerOptions())
+                .Should()
+                .BeEquivalentTo(new Car() { Doors = null });
+        }
+
         [Test]
         public void StringAttribute()
         {
@@ -42,6 +55,19 @@ public void StringAttribute()
                 .BeEquivalentTo(new Car() { Name = "Mystery Machine" });
         }
 
+        [Test]
+        public void EnumAttribute()
+        {
+            var document = new OclDocument()
+            {
+                new OclAttribute("Type", "Suv")
+            };
+
+            OclConvert.Deserialize<Car>(document, new OclSerializerOptions())
+                .Should()
+                .BeEquivalentTo(new Car() { Type = CarType.Suv });
+        }
+
         [Test]
         public void Block()
         {
@@ -127,9 +153,16 @@ public void ExceptionIsThrownIfPropertyDoesNotExist()
         class Car
         {
             public string Name { get; set; } = "";
-            public int Doors { get; set; }
+            public int? Doors { get; set; }
             public Person? Driver { get; set; }
             public List<Person>? Passengers { get; set; }
+            public CarType Type { get; set; }
+        }
+
+        enum CarType
+        {
+            Hatchback,
+            Suv
         }
 
         class Person
diff --git a/source/Tests/ToOclDoc/ToOclBodyDefaultBehaviourFixture.cs b/source/Tests/ToOclDoc/ToOclBodyDefaultBehaviourFixture.cs
index 4904e86..b571d48 100644
--- a/source/Tests/ToOclDoc/ToOclBodyDefaultBehaviourFixture.cs
+++ b/source/Tests/ToOclDoc/ToOclBodyDefaultBehaviourFixture.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Reflection;
 using NUnit.Framework;
 using Octopus.Ocl;
 
@@ -47,6 +48,22 @@ public void ListOfComplexTypesProperty()
                 );
         }
 
+        [Test]
+        public void Enum()
+        {
+            var data = new
+            {
+                MyProp = BindingFlags.Static
+            };
+
+            var result = OclConvert.ToOclDocument(data, new OclSerializerOptions());
+
+            result.Should()
+                .HaveChildrenExactly(
+                    new OclAttribute("MyProp", "Static")
+                );
+        }
+
         class Car
         {
             public int Doors { get; } = 2;