[XamlC] Allow Properties and BP of generic types (#995)

* [XamlC] Allow Properties and BP of generic types

* try hard to convince the compiler that the variable is initialized

* Update MethodDefinitionExtensions.cs

9 files changed, 201 insertions, 57 deletions

diff --git a/Xamarin.Forms.Build.Tasks/BindablePropertyReferenceExtensions.cs b/Xamarin.Forms.Build.Tasks/BindablePropertyReferenceExtensions.cs
index 0edc5f59..014f9d62 100644
--- a/Xamarin.Forms.Build.Tasks/BindablePropertyReferenceExtensions.cs
+++ b/Xamarin.Forms.Build.Tasks/BindablePropertyReferenceExtensions.cs
@@ -17,9 +17,9 @@ namespace Xamarin.Forms.Build.Tasks
 				throw new XamlParseException($"The name of the bindable property {bpRef.Name} does not ends with \"Property\". This is the kind of convention the world is build upon, a bit like Planck's constant.", iXmlLineInfo);
 			var bpName = bpRef.Name.Substring(0, bpRef.Name.Length - 8);
 			var owner = bpRef.DeclaringType;
-			TypeReference _;
+			TypeReference declaringTypeRef = null;
 
-			var getter = owner.GetProperty(pd => pd.Name == bpName, out _)?.GetMethod;
+			var getter = owner.GetProperty(pd => pd.Name == bpName, out declaringTypeRef)?.GetMethod;
 			if (getter == null || getter.IsStatic || !getter.IsPublic)
 				getter = null;
 			getter = getter ?? owner.GetMethods(md => md.Name == $"Get{bpName}" &&
@@ -27,18 +27,18 @@ namespace Xamarin.Forms.Build.Tasks
 												md.IsPublic &&
 												md.Parameters.Count == 1 &&
 												md.Parameters[0].ParameterType.InheritsFromOrImplements(module.ImportReference(typeof(BindableObject))), module).SingleOrDefault()?.Item1;
-
 			if (getter == null)
 				throw new XamlParseException($"Missing a public static Get{bpName} or a public instance property getter for the attached property \"{bpRef.DeclaringType}.{bpRef.Name}\"", iXmlLineInfo);
-			return getter.ReturnType;
+			return getter.ResolveGenericReturnType(declaringTypeRef, module);
 		}
 
 		public static TypeReference GetBindablePropertyTypeConverter(this FieldReference bpRef, ModuleDefinition module)
 		{
-			TypeReference _;
+			TypeReference propertyDeclaringType;
 			var owner = bpRef.DeclaringType;
 			var bpName = bpRef.Name.EndsWith("Property", StringComparison.Ordinal) ? bpRef.Name.Substring(0, bpRef.Name.Length - 8) : bpRef.Name;
-			var property = owner.GetProperty(pd => pd.Name == bpName, out _);
+			var property = owner.GetProperty(pd => pd.Name == bpName, out propertyDeclaringType);
+			var propertyType = property?.ResolveGenericPropertyType(propertyDeclaringType, module);
 			var staticGetter = owner.GetMethods(md => md.Name == $"Get{bpName}" &&
 												md.IsStatic &&
 												md.IsPublic &&
@@ -48,8 +48,8 @@ namespace Xamarin.Forms.Build.Tasks
 			var attributes = new List<CustomAttribute>();
 			if (property != null && property.HasCustomAttributes)
 				attributes.AddRange(property.CustomAttributes);
-			if (property != null && property.PropertyType.Resolve().HasCustomAttributes)
-				attributes.AddRange(property.PropertyType.Resolve().CustomAttributes);
+			if (propertyType != null && propertyType.Resolve().HasCustomAttributes)
+				attributes.AddRange(propertyType.Resolve().CustomAttributes);
 			if (staticGetter != null && staticGetter.HasCustomAttributes)
 				attributes.AddRange(staticGetter.CustomAttributes);
 			if (staticGetter != null && staticGetter.ReturnType.Resolve().HasCustomAttributes)
diff --git a/Xamarin.Forms.Build.Tasks/MethodDefinitionExtensions.cs b/Xamarin.Forms.Build.Tasks/MethodDefinitionExtensions.cs
index 4b50b64d..6c6c7d88 100644
--- a/Xamarin.Forms.Build.Tasks/MethodDefinitionExtensions.cs
+++ b/Xamarin.Forms.Build.Tasks/MethodDefinitionExtensions.cs
@@ -38,5 +38,18 @@ namespace Xamarin.Forms.Build.Tasks
 			}
 			return true;
 		}
+
+		public static TypeReference ResolveGenericReturnType(this MethodDefinition self, TypeReference declaringTypeRef, ModuleDefinition module)
+		{
+			if (self == null)
+				throw new System.ArgumentNullException(nameof(self));
+			if (declaringTypeRef == null)
+				throw new System.ArgumentNullException(nameof(declaringTypeRef));
+			if (!self.ReturnType.IsGenericParameter)
+				return self.ReturnType;
+
+			var t = ((GenericInstanceType)declaringTypeRef).GenericArguments[((GenericParameter)self.ReturnType).Position];
+			return t;
+		}
 	}
-}
\ No newline at end of file
+}
diff --git a/Xamarin.Forms.Build.Tasks/PropertyDefinitionExtensions.cs b/Xamarin.Forms.Build.Tasks/PropertyDefinitionExtensions.cs
index 7a56c9d1..8cbbbe4a 100644
--- a/Xamarin.Forms.Build.Tasks/PropertyDefinitionExtensions.cs
+++ b/Xamarin.Forms.Build.Tasks/PropertyDefinitionExtensions.cs
@@ -5,11 +5,17 @@ namespace Xamarin.Forms.Build.Tasks
 {
 	static class PropertyDefinitionExtensions
 	{
-		public static TypeReference ResolveGenericPropertyType(this PropertyDefinition self, TypeReference declaringTypeReference)
+		public static TypeReference ResolveGenericPropertyType(this PropertyDefinition self, TypeReference declaringTypeRef,
+			ModuleDefinition module)
 		{
-			if (self.PropertyType.IsGenericParameter)
-				return ((GenericInstanceType)declaringTypeReference).GenericArguments [((GenericParameter)self.PropertyType).Position];
-			return self.PropertyType;
+			if (self == null)
+				throw new ArgumentNullException(nameof(self));
+			if (declaringTypeRef == null)
+				throw new ArgumentNullException(nameof(declaringTypeRef));
+			if (!self.PropertyType.IsGenericParameter)
+				return self.PropertyType;
+
+			return ((GenericInstanceType)declaringTypeRef).GenericArguments [((GenericParameter)self.PropertyType).Position];
 		}
 	}
 }
\ No newline at end of file
diff --git a/Xamarin.Forms.Build.Tasks/SetPropertiesVisitor.cs b/Xamarin.Forms.Build.Tasks/SetPropertiesVisitor.cs
index 5cbf075d..f7da7689 100644
--- a/Xamarin.Forms.Build.Tasks/SetPropertiesVisitor.cs
+++ b/Xamarin.Forms.Build.Tasks/SetPropertiesVisitor.cs
@@ -967,7 +967,7 @@ namespace Xamarin.Forms.Build.Tasks
 				return false;
 
 			var vardef = context.Variables [elementNode];
-			var propertyType = property.ResolveGenericPropertyType(declaringTypeReference);
+			var propertyType = property.ResolveGenericPropertyType(declaringTypeReference, module);
 			var implicitOperator = vardef.VariableType.GetImplicitOperatorTo(propertyType, module);
 
 			if (implicitOperator != null)
@@ -998,7 +998,7 @@ namespace Xamarin.Forms.Build.Tasks
 			module.ImportReference(parent.VariableType.Resolve());
 			var propertySetterRef = module.ImportReference(module.ImportReference(propertySetter).ResolveGenericParameters(declaringTypeReference, module));
 			propertySetterRef.ImportTypes(module);
-			var propertyType = property.ResolveGenericPropertyType(declaringTypeReference);
+			var propertyType = property.ResolveGenericPropertyType(declaringTypeReference, module);
 			var valueNode = node as ValueNode;
 			var elementNode = node as IElementNode;
 
diff --git a/Xamarin.Forms.Xaml.UnitTests/Issues/Bz53350.xaml b/Xamarin.Forms.Xaml.UnitTests/Issues/Bz53350.xaml
new file mode 100644
index 00000000..ad664ba0
--- /dev/null
+++ b/Xamarin.Forms.Xaml.UnitTests/Issues/Bz53350.xaml
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
+    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    xmlns:local="clr-namespace:Xamarin.Forms.Xaml.UnitTests"
+    x:Class="Xamarin.Forms.Xaml.UnitTests.Bz53350">
+    <local:Bz53350String x:Name="content"  SomeBP="Foo" SomeProperty="Bar" />
+</ContentPage>
\ No newline at end of file
diff --git a/Xamarin.Forms.Xaml.UnitTests/Issues/Bz53350.xaml.cs b/Xamarin.Forms.Xaml.UnitTests/Issues/Bz53350.xaml.cs
new file mode 100644
index 00000000..f25c018a
--- /dev/null
+++ b/Xamarin.Forms.Xaml.UnitTests/Issues/Bz53350.xaml.cs
@@ -0,0 +1,63 @@
+using System;
+using NUnit.Framework;
+using Xamarin.Forms.Core.UnitTests;
+
+namespace Xamarin.Forms.Xaml.UnitTests
+{
+	public class Bz53350Generic<T> : ContentView
+	{
+		public static readonly BindableProperty SomeBPProperty =
+			BindableProperty.Create("SomeBP", typeof(T), typeof(Bz53350Generic<T>), default(T));
+
+		public T SomeBP
+		{
+			get { return (T)GetValue(SomeBPProperty); }
+			set { SetValue(SomeBPProperty, value); }
+		}
+
+		public T SomeProperty { get; set; }
+	}
+
+	public class Bz53350String : Bz53350Generic<string>
+	{
+		
+	}
+
+	public partial class Bz53350
+	{
+		public Bz53350()
+		{
+		}
+
+		public Bz53350(bool useCompiledXaml)
+		{
+			//this stub will be replaced at compile time
+		}
+
+		[TestFixture]
+		class Tests
+		{
+			[SetUp]
+			public void Setup()
+			{
+				Device.PlatformServices = new MockPlatformServices();
+			}
+
+			[TearDown]
+			public void TearDown()
+			{
+				Application.Current = null;
+				Device.PlatformServices = null;
+			}
+
+			[TestCase(true)]
+			[TestCase(false)]
+			public void PropertiesWithGenericType(bool useCompiledXaml)
+			{
+				var layout = new Bz53350(useCompiledXaml);
+				Assert.That(layout.content.SomeBP, Is.EqualTo("Foo"));
+				Assert.That(layout.content.SomeProperty, Is.EqualTo("Bar"));
+			}
+		}
+	}
+}
diff --git a/Xamarin.Forms.Xaml.UnitTests/Xamarin.Forms.Xaml.UnitTests.csproj b/Xamarin.Forms.Xaml.UnitTests/Xamarin.Forms.Xaml.UnitTests.csproj
index d528379e..ba470e60 100644
--- a/Xamarin.Forms.Xaml.UnitTests/Xamarin.Forms.Xaml.UnitTests.csproj
+++ b/Xamarin.Forms.Xaml.UnitTests/Xamarin.Forms.Xaml.UnitTests.csproj
@@ -491,6 +491,10 @@
     <Compile Include="Issues\Bz56852.xaml.cs">
       <DependentUpon>Bz56852.xaml</DependentUpon>
     </Compile>
+    <Compile Include="Issues\Bz53350.xaml.cs">
+      <DependentUpon>Bz53350.xaml</DependentUpon>
+    </Compile>
+    <Compile Include="XamlC\MethodDefinitionExtensionsTests.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <Import Project="..\.nuspec\Xamarin.Forms.Debug.targets" />
@@ -899,6 +903,9 @@
     <EmbeddedResource Include="Issues\Bz56852.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Include="Issues\Bz53350.xaml">
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
 	</ItemGroup>
   <ItemGroup>
     <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
diff --git a/Xamarin.Forms.Xaml.UnitTests/XamlC/MethodDefinitionExtensionsTests.cs b/Xamarin.Forms.Xaml.UnitTests/XamlC/MethodDefinitionExtensionsTests.cs
new file mode 100644
index 00000000..6133d727
--- /dev/null
+++ b/Xamarin.Forms.Xaml.UnitTests/XamlC/MethodDefinitionExtensionsTests.cs
@@ -0,0 +1,61 @@
+using System;
+using System.Linq;
+
+using Mono.Cecil;
+
+using Xamarin.Forms.Build.Tasks;
+
+using NUnit.Framework;
+using System.Collections.Generic;
+
+namespace Xamarin.Forms.Xaml.XamlcUnitTests
+{
+	[TestFixture]
+	public class MethodDefinitionExtensionsTests
+	{
+		public class NonGenericClass
+		{
+			public object Property { get; set; }
+		}
+
+		public class GenericClass<T, U, V>
+		{
+			public object NonGeneric() => default(object);
+			public T GenericT() => default(T);
+			public U GenericU() => default(U);
+			public V GenericV() => default(V);
+			public IEnumerable<T> EnumerableT() => default(IEnumerable<T>);
+			public KeyValuePair<V, U> KvpVU() => default(KeyValuePair<V,U>);
+		}
+
+		ModuleDefinition module;
+
+		[SetUp]
+		public void SetUp()
+		{
+			module = ModuleDefinition.CreateModule("foo", ModuleKind.Dll);
+		}
+
+		[Test]
+		public void ResolveGenericReturnType()
+		{
+			var type = module.ImportReference(typeof(GenericClass<bool, string, int>));
+
+			var getter = type.GetMethods(md => md.Name == "NonGeneric", module).Single();
+			var returnType = getter.Item1.ResolveGenericReturnType(getter.Item2, module);
+			Assert.AreEqual("System.Object", returnType.FullName);
+
+			getter = type.GetMethods(md => md.Name == "GenericT", module).Single();
+			returnType = getter.Item1.ResolveGenericReturnType(getter.Item2, module);
+			Assert.AreEqual("System.Boolean", returnType.FullName);
+
+			getter = type.GetMethods(md => md.Name == "GenericU", module).Single();
+			returnType = getter.Item1.ResolveGenericReturnType(getter.Item2, module);
+			Assert.AreEqual("System.String", returnType.FullName);
+
+			getter = type.GetMethods(md => md.Name == "GenericV", module).Single();
+			returnType = getter.Item1.ResolveGenericReturnType(getter.Item2, module);
+			Assert.AreEqual("System.Int32", returnType.FullName);
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Xaml.UnitTests/XamlC/PropertyDefinitionExtensionsTests.cs b/Xamarin.Forms.Xaml.UnitTests/XamlC/PropertyDefinitionExtensionsTests.cs
index b43e4c9d..e8e56afa 100644
--- a/Xamarin.Forms.Xaml.UnitTests/XamlC/PropertyDefinitionExtensionsTests.cs
+++ b/Xamarin.Forms.Xaml.UnitTests/XamlC/PropertyDefinitionExtensionsTests.cs
@@ -6,6 +6,7 @@ using Mono.Cecil;
 using Xamarin.Forms.Build.Tasks;
 
 using NUnit.Framework;
+using System.Collections.Generic;
 
 namespace Xamarin.Forms.Xaml.XamlcUnitTests
 {
@@ -17,10 +18,14 @@ namespace Xamarin.Forms.Xaml.XamlcUnitTests
 			public object Property { get; set; }
 		}
 
-		public class GenericClass<T>
+		public class GenericClass<T, U, V>
 		{
 			public object Property { get; set; }
-			public T GenericProperty { get; set; }
+			public T GenericT { get; set; }
+			public U GenericU { get; set; }
+			public V GenericV { get; set; }
+			public IEnumerable<T> EnumerableT { get; set; }
+			public KeyValuePair<V, U> KvpVU { get; set; }
 		}
 
 		ModuleDefinition module;
@@ -31,45 +36,27 @@ namespace Xamarin.Forms.Xaml.XamlcUnitTests
 			module = ModuleDefinition.CreateModule ("foo", ModuleKind.Dll);
 		}
 
-//		[Test]
-//		public void ResolveGenericsOnNonGenericPreserveAccessors ()
-//		{
-//			var type = module.Import (typeof (NonGenericClass));
-//			TypeReference declaringTypeReference;
-//			PropertyDefinition prop = type.GetProperty (fd => fd.Name == "Property", out declaringTypeReference);
-//			Assert.AreEqual ("System.Object", prop.PropertyType.FullName);
-//			Assert.AreEqual ("System.Void Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/NonGenericClass::set_Property(System.Object)", prop.SetMethod.FullName);
-//			Assert.AreEqual ("System.Object Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/NonGenericClass::get_Property()", prop.GetMethod.FullName);
-//			Assert.AreEqual ("Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/NonGenericClass", prop.DeclaringType.FullName);
-//
-//			prop.ResolveGenericParameters (declaringTypeReference);
-//
-//			Assert.AreEqual ("System.Object", prop.PropertyType.FullName);
-//			Assert.AreEqual ("System.Void Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/NonGenericClass::set_Property(System.Object)", prop.SetMethod.FullName);
-//			Assert.AreEqual ("System.Object Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/NonGenericClass::get_Property()", prop.GetMethod.FullName);
-//			Assert.AreEqual ("Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/NonGenericClass", prop.DeclaringType.FullName);
-//
-//		}
-//
-//		[Test]
-//		public void NonGenericPropertyOnGenericType ()
-//		{
-//			var type = module.Import (typeof (GenericClass<bool>));
-//			TypeReference declaringTypeReference;
-//			PropertyDefinition prop = type.GetProperty (fd => fd.Name == "Property", out declaringTypeReference);
-//			Assert.AreEqual ("System.Object", prop.PropertyType.FullName);
-//			Assert.AreEqual ("System.Void Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/GenericClass`1::set_Property(System.Object)", prop.SetMethod.FullName);
-//			Assert.AreEqual ("System.Object Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/GenericClass`1::get_Property()", prop.GetMethod.FullName);
-//			Assert.AreEqual ("Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/GenericClass`1", prop.DeclaringType.FullName);
-//			Assert.False (prop.DeclaringType.IsGenericInstance);
-//
-//			prop.ResolveGenericParameters (declaringTypeReference);
-//			Assert.AreEqual ("System.Object", prop.PropertyType.FullName);
-//			Assert.AreEqual ("System.Void Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/GenericClass`1::set_Property(System.Object)", prop.SetMethod.FullName);
-//			Assert.AreEqual ("System.Object Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/GenericClass`1::get_Property()", prop.GetMethod.FullName);
-//			Assert.AreEqual ("Xamarin.Forms.Xaml.XamlcUnitTests.PropertyDefinitionExtensionsTests/GenericClass`1", prop.DeclaringType.FullName);
-//			Assert.True (prop.DeclaringType.IsGenericInstance);
-//
-//		}
+		[Test]
+		public void ResolveGenericPropertyType ()
+		{
+			var type = module.ImportReference (typeof (GenericClass<bool, string, int>));
+			TypeReference declaringTypeReference;
+			var prop = type.GetProperty (fd => fd.Name == "Property", out declaringTypeReference);
+			var propertyType = prop.ResolveGenericPropertyType (declaringTypeReference, module);
+			Assert.AreEqual ("System.Object", propertyType.FullName);
+
+			prop = type.GetProperty(fd => fd.Name == "GenericT", out declaringTypeReference);
+			propertyType = prop.ResolveGenericPropertyType(declaringTypeReference, module);
+			Assert.AreEqual("System.Boolean", propertyType.FullName);
+
+			prop = type.GetProperty(fd => fd.Name == "GenericU", out declaringTypeReference);
+			propertyType = prop.ResolveGenericPropertyType(declaringTypeReference, module);
+			Assert.AreEqual("System.String", propertyType.FullName);
+
+			prop = type.GetProperty(fd => fd.Name == "GenericV", out declaringTypeReference);
+			propertyType = prop.ResolveGenericPropertyType(declaringTypeReference, module);
+			Assert.AreEqual("System.Int32", propertyType.FullName);
+
+		}
 	}
 }
\ No newline at end of file