Support for inherited IMemoryCache property, closes #2

Author: pergerch

src/SpatialFocus.MethodCache.Fody/Extensions/TypeDefinitionExtension.cs

@@ -39,7 +39,24 @@ public static bool IsEligibleForWeaving(this TypeDefinition typeDefinition, Refe
 				throw new ArgumentNullException(nameof(references));
 			}
 
-			return typeDefinition.Properties.Where(propertyDefinition =>
+			bool isEligibleForWeaving = typeDefinition.TryGetCacheGetterProperty(references) != null;
+
+			return isEligibleForWeaving;
+		}
+
+		public static PropertyDefinition TryGetCacheGetterProperty(this TypeDefinition typeDefinition, References references)
+		{
+			if (typeDefinition == null)
+			{
+				throw new ArgumentNullException(nameof(typeDefinition));
+			}
+
+			if (references == null)
+			{
+				throw new ArgumentNullException(nameof(references));
+			}
+
+			PropertyDefinition property = typeDefinition.Properties.Where(propertyDefinition =>
 				{
 					TypeDefinition propertyTypeDefinition = propertyDefinition.PropertyType.Resolve();
 					TypeDefinition memoryCacheInterface = references.MemoryCacheInterface.Resolve();
@@ -61,7 +78,15 @@ public static bool IsEligibleForWeaving(this TypeDefinition typeDefinition, Refe
 
 					return false;
 				})
-				.Count() == 1;
+				.SingleOrDefault();
+
+			if (property == null && typeDefinition.BaseType != null)
+			{
+				TypeDefinition baseTypeDefinition = typeDefinition.BaseType.Resolve();
+				property = baseTypeDefinition.TryGetCacheGetterProperty(references);
+			}
+
+			return property;
 		}
 
 		public static CustomAttribute TryGetCacheAttribute(this TypeDefinition typeDefinition, References references)

src/SpatialFocus.MethodCache.Fody/MemoryCache.cs

@@ -51,37 +51,16 @@ public static MethodReference GetCacheGetterMethod(ClassWeavingContext classWeav
 			}
 
 			// TODO: Check if this can be inherited, extract to class level
-			List<PropertyDefinition> propertyDefinitions = classWeavingContext.TypeDefinition.Properties.Where(definition =>
-				{
-					TypeDefinition typeDefinition = definition.PropertyType.Resolve();
-					TypeDefinition memoryCacheInterface = classWeavingContext.References.MemoryCacheInterface.Resolve();
-
-					if (definition.GetMethod.IsStatic)
-					{
-						return false;
-					}
-
-					if (typeDefinition.IsInterface && typeDefinition.Equals(memoryCacheInterface))
-					{
-						return true;
-					}
-
-					if (typeDefinition.Interfaces.Any(x => x.InterfaceType == memoryCacheInterface))
-					{
-						return true;
-					}
-
-					return false;
-				})
-				.ToList();
+			PropertyDefinition propertyDefinition =
+				classWeavingContext.TypeDefinition.TryGetCacheGetterProperty(classWeavingContext.References);
 
 			// TODO: Also check fields
-			if (propertyDefinitions.Count != 1)
+			if (propertyDefinition == null)
 			{
 				throw new WeavingException("Property not found");
 			}
 
-			MethodDefinition methodDefinition = propertyDefinitions.Single().GetMethod;
+			MethodDefinition methodDefinition = propertyDefinition.GetMethod;
 
 			if (methodDefinition.DeclaringType.GenericParameters.Any())
 			{

src/SpatialFocus.MethodCache.TestAssembly/DerivedTestClass.cs

@@ -0,0 +1,35 @@
+// <copyright file="DerivedTestClass.cs" company="Spatial Focus GmbH">
+// Copyright (c) Spatial Focus GmbH. All rights reserved.
+// </copyright>
+
+namespace SpatialFocus.MethodCache.TestAssembly
+{
+	using Microsoft.Extensions.Caching.Memory;
+
+	[Cache]
+	public class DerivedTestClass : BaseClass
+	{
+		public DerivedTestClass(IMemoryCache memoryCache) : base(memoryCache)
+		{
+		}
+
+#pragma warning disable CA1822 // Mark members as static
+		public int Add(int a, int b)
+		{
+			return a + b;
+		}
+#pragma warning restore CA1822 // Mark members as static
+	}
+
+#pragma warning disable SA1402 // File may only contain a single type
+	public class BaseClass
+	{
+		public BaseClass(IMemoryCache memoryCache)
+		{
+			MemoryCache = memoryCache;
+		}
+
+		public IMemoryCache MemoryCache { get; }
+	}
+#pragma warning restore SA1402 // File may only contain a single type
+}

src/SpatialFocus.MethodCache.Tests/MemoryCacheBasicTests.cs

@@ -83,5 +83,19 @@ public void BasicTest4NoCache()
 			Assert.Equal(0, mockMemoryCache.CountSets);
 			Assert.Equal(0, mockMemoryCache.CountGets);
 		}
+
+		[Fact]
+		public void BasicTest5DerivedClass()
+		{
+			using MockMemoryCache mockMemoryCache = new MockMemoryCache();
+
+			dynamic instance = TestHelpers.CreateInstance<DerivedTestClass>(MemoryCacheBasicTests.TestResult.Assembly, mockMemoryCache);
+
+			dynamic result = instance.Add(1, 2);
+
+			Assert.Equal(3, result);
+			Assert.Equal(1, mockMemoryCache.CountSets);
+			Assert.Equal(1, mockMemoryCache.CountGets);
+		}
 	}
 }