Merge pull request #5 from servicetitan/supporting-resolver-overrides

Add supporting of unity resolver overrides.

Author: hypercodeplace

LazyProxy.Unity.Tests/UnityExtensionTests.cs

@@ -5,7 +5,9 @@
 using Unity.Exceptions;
 using Unity.Injection;
 using Unity.Lifetime;
+using Unity.Resolution;
 using Xunit;
+using DependencyAttribute = Unity.Attributes.DependencyAttribute;
 
 [assembly: InternalsVisibleTo("LazyProxy.DynamicTypes")]
 
@@ -60,6 +62,11 @@ public Service2()
             public string Method(string arg) => "service2->" + arg;
         }
 
+        private class Service2Ex : IService2
+        {
+            public string Method(string arg) => "service2Ex->" + arg;
+        }
+
         internal interface IInternalService
         {
             string Get();
@@ -126,6 +133,47 @@ public DerivedGenericService(string value)
             }
         }
 
+        public class Argument
+        {
+            public string StringValue { get; }
+
+            public Argument(string stringValue)
+            {
+                StringValue = stringValue;
+            }
+        }
+
+        enum SomeEnum
+        {
+            Value1,
+            Value2
+        }
+
+        public interface IServiceToTestOverrides
+        {
+            string Property { get; set; }
+            string Get(string arg);
+        }
+
+        private class ServiceToTestOverrides : IServiceToTestOverrides
+        {
+            private readonly SomeEnum _someEnum;
+            private readonly IService2 _service;
+            private readonly Argument _argument;
+
+            [Dependency]
+            public string Property { get; set; }
+
+            public string Get(string arg) => $"{_someEnum}_{_service.Method(arg)}_{Property}_{_argument.StringValue}";
+
+            public ServiceToTestOverrides(SomeEnum someEnum, IService2 service, Argument argument)
+            {
+                _someEnum = someEnum;
+                _service = service;
+                _argument = argument;
+            }
+        }
+
         [Fact]
         public void ServiceCtorMustBeExecutedAfterMethodIsCalledAndOnlyOnce()
         {
@@ -487,5 +535,22 @@ public void GenericServicesMustBeResolvedByNameWithCorrectInjectionMembers()
             Assert.Equal($"Argument1A_Argument2_Int32_{value1}", service1.Get(new Argument1A(), new Argument2(), 42).Value);
             Assert.Equal($"Argument1A_Argument2_Int32_{value2}", service2.Get(new Argument1A(), new Argument2(), 42).Value);
         }
+
+        [Fact]
+        public void OverridesMustBeAppliedByProxy()
+        {
+            var result = new UnityContainer()
+                .RegisterType<IService2, Service2>()
+                .RegisterLazy<IServiceToTestOverrides, ServiceToTestOverrides>()
+                .Resolve<IServiceToTestOverrides>(
+                    new ParameterOverride("someEnum", SomeEnum.Value2),
+                    new DependencyOverride(typeof(IService2), new Service2Ex()),
+                    new PropertyOverride("Property", "propertyValue"),
+                    new TypeBasedOverride(typeof(Argument), new ParameterOverride("stringValue", "stringValue"))
+                )
+                .Get("arg");
+
+            Assert.Equal("Value2_service2Ex->arg_propertyValue_stringValue", result);
+        }
     }
 }

LazyProxy.Unity/UnityExtensions.cs

@@ -1,6 +1,5 @@
 using System;
 using Unity;
-using Unity.Injection;
 using Unity.Lifetime;
 using Unity.Registration;
 
@@ -154,8 +153,8 @@ public static IUnityContainer RegisterLazy(this IUnityContainer container,
 
             return container
                 .RegisterType(typeFrom, typeTo, registrationName, getLifetimeManager(), injectionMembers)
-                .RegisterType(typeFrom, name, getLifetimeManager(), new InjectionFactory(
-                    (c, t, n) => LazyProxyBuilder.CreateInstance(t, () => c.Resolve(t, registrationName))));
+                .RegisterType(typeFrom, name, getLifetimeManager(), new UnityInjectionFactory(
+                    (c, t, n, o) => LazyProxyBuilder.CreateInstance(t, () => c.Resolve(t, registrationName, o))));
         }
     }
 }

LazyProxy.Unity/UnityInjectionFactory.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using Unity;
+using Unity.Builder;
+using Unity.Injection;
+using Unity.Policy;
+using Unity.Registration;
+using Unity.Resolution;
+
+namespace LazyProxy.Unity
+{
+    /// <summary>
+    /// A class that lets you specify a factory method the container will use to create the object.
+    /// </summary>
+    public class UnityInjectionFactory : InjectionMember, IInjectionFactory, IBuildPlanPolicy
+    {
+        private static readonly FieldInfo ResolverOverrides = typeof(BuilderContext)
+            .GetField("_resolverOverrides", BindingFlags.Instance | BindingFlags.NonPublic);
+
+        private readonly Func<IUnityContainer, Type, string, ResolverOverride[], object> _factoryFunc;
+
+        /// <summary>
+        /// Create a new instance of <see cref="UnityInjectionFactory"/> with the given factory function.
+        /// </summary>
+        /// <param name="factoryFunc">Factory function.</param>
+        public UnityInjectionFactory(Func<IUnityContainer, Type, string, ResolverOverride[], object> factoryFunc)
+        {
+            _factoryFunc = factoryFunc ?? throw new ArgumentNullException(nameof(factoryFunc));
+        }
+
+        /// <summary>
+        /// Add policies to the policies to configure the container
+        /// to call this constructor with the appropriate parameter values.
+        /// </summary>
+        /// <param name="serviceType">Type of interface being registered. If no interface, this will be null.
+        /// This parameter is ignored in this implementation.</param>
+        /// <param name="implementationType">Type of concrete type being registered.</param>
+        /// <param name="name">Name used to resolve the type object.</param>
+        /// <param name="policies">Policy list to add policies to.</param>
+        public override void AddPolicies(Type serviceType, Type implementationType, string name, IPolicyList policies)
+        {
+            policies.Set(serviceType, name, typeof(IBuildPlanPolicy), this);
+        }
+
+        /// <summary>
+        /// Creates an instance of this build plan's type, or fills in the existing type if passed in.
+        /// </summary>
+        /// <param name="context">Context used to build up the object.</param>
+        /// <exception cref="ArgumentNullException">Context is null.</exception>
+        public void BuildUp(IBuilderContext context)
+        {
+            if (context == null)
+                throw new ArgumentNullException(nameof(context));
+
+            if (context.Existing != null)
+                return;
+
+            var resolverOverride = ResolverOverrides.GetValue(context);
+
+            var resolverOverrides = resolverOverride == null
+                ? new ResolverOverride[] { }
+                : ((IEnumerable<ResolverOverride>)resolverOverride).ToArray();
+
+            var container = context.Container;
+            var type = context.BuildKey.Type;
+            var name = context.BuildKey.Name;
+
+            context.Existing = _factoryFunc(container, type, name, resolverOverrides);
+            context.SetPerBuildSingleton();
+        }
+    }
+}