Add most support for type hierarchies.

Author: AArnott

ImmutableObjectGraph.CodeGeneration.Tests/CodeGenTests.cs

@@ -95,6 +95,14 @@ public async Task OneScalarFieldWithBuilder_BuilderHasToImmutableMethod()
             Assert.True(result.DeclaredMethods.Any(m => m.ContainingType?.Name == "Builder" && m.Name == "ToImmutable" && m.Parameters.Length == 0 && !m.IsStatic));
         }
 
+        [Fact]
+        public async Task ClassDerivesFromAnotherWithFields_DerivedCreateParametersIncludeBaseFields()
+        {
+            var result = await this.GenerateFromStreamAsync("ClassDerivesFromAnotherWithFields");
+            Assert.True(result.DeclaredMethods.Any(m => m.ContainingType?.Name == "Fruit" && m.Name == "Create" && m.Parameters.Length == 1));
+            Assert.True(result.DeclaredMethods.Any(m => m.ContainingType?.Name == "Apple" && m.Name == "Create" && m.Parameters.Length == 2));
+        }
+
         protected async Task<GenerationResult> GenerateFromStreamAsync(string testName)
         {
             using (var stream = Assembly.GetExecutingAssembly().GetManifestResourceStream(this.GetType().Namespace + ".TestSources." + testName + ".cs"))

ImmutableObjectGraph.CodeGeneration.Tests/ImmutableObjectGraph.CodeGeneration.Tests.csproj

@@ -108,6 +108,7 @@
   <ItemGroup>
     <Compile Include="CodeGenTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <EmbeddedResource Include="TestSources\ClassDerivesFromAnotherWithFields.cs" />
     <EmbeddedResource Include="TestSources\OneScalarFieldWithBuilder.cs" />
     <EmbeddedResource Include="TestSources\OneScalarField.cs" />
     <EmbeddedResource Include="TestSources\FamilyPersonWatch.cs" />

ImmutableObjectGraph.CodeGeneration.Tests/TestSources/ClassDerivesFromAnotherWithFields.cs

@@ -0,0 +1,11 @@
+[ImmutableObjectGraph.CodeGeneration.GenerateImmutable]
+partial class Fruit
+{
+    readonly int seeds;
+}
+
+[ImmutableObjectGraph.CodeGeneration.GenerateImmutable]
+partial class Apple : Fruit
+{
+    readonly string color;
+}