[ConstructorQueryProvider] Implement a class to provide a constructor…

… query API.

Wingman.Tests/DI/ConstructorQueryProviderTests.cs

@@ -0,0 +1,112 @@
+namespace Wingman.Tests.DI
+{
+    using System;
+    using System.Linq;
+    using System.Reflection;
+
+    using Moq;
+
+    using Wingman.DI;
+
+    using Xunit;
+
+    public class ConstructorQueryProviderTests
+    {
+        private readonly Mock<IConstructorFactory> _constructorFactoryMock;
+
+        private readonly ConstructorQueryProvider _constructorQueryProvider;
+
+        public ConstructorQueryProviderTests()
+        {
+            _constructorFactoryMock = new Mock<IConstructorFactory>();
+
+            _constructorQueryProvider = new ConstructorQueryProvider(_constructorFactoryMock.Object);
+        }
+
+        [Fact]
+        public void TestMapsPublicConstructor()
+        {
+            MapConstructorsOf<ServiceWithPublicConstructor>();
+
+            VerifyMakeConstructorCalled<ServiceWithPublicConstructor>(expectedConstructors: 1);
+        }
+
+        [Fact]
+        public void TestMapsMultiplePublicConstructorsAndNotHiddenOnes()
+        {
+            MapConstructorsOf<ServiceWithPublicAndHiddenConstructors>();
+
+            VerifyMakeConstructorCalled<ServiceWithPublicAndHiddenConstructors>(expectedConstructors: 3);
+        }
+
+        [Fact]
+        public void TestDoesNotMapHiddenConstructor()
+        {
+            MapConstructorsOf<ServiceWithHiddenConstructor>();
+
+            VerifyMakeConstructorCalled<ServiceWithHiddenConstructor>(expectedConstructors: 0);
+        }
+
+        [Fact]
+        public void TestDoesNotMapStaticConstructor()
+        {
+            MapConstructorsOf<ServiceWithStaticConstructor>();
+
+            VerifyMakeConstructorCalled<ServiceWithStaticConstructor>(expectedConstructors: 0);
+        }
+
+        private void MapConstructorsOf<T>()
+        {
+            MapConstructors(typeof(T));
+        }
+
+        private void MapConstructors(Type type)
+        {
+            _constructorQueryProvider.QueryPublicInstanceConstructors(type).ToArray();
+        }
+
+        private void VerifyMakeConstructorCalled<T>(int expectedConstructors)
+        {
+            ConstructorInfo[] constructors = typeof(T).GetConstructors();
+
+            Assert.Equal(expectedConstructors, constructors.Length);
+
+            foreach (ConstructorInfo constructor in constructors)
+            {
+                _constructorFactoryMock.Verify(factory => factory.CreateConstructor(constructor), Times.Once);
+            }
+
+            _constructorFactoryMock.VerifyNoOtherCalls();
+        }
+
+        private class ServiceWithPublicConstructor
+        {
+            public ServiceWithPublicConstructor(object _) { }
+        }
+
+         class ServiceWithPublicAndHiddenConstructors
+        {
+            public ServiceWithPublicAndHiddenConstructors() { }
+
+            public ServiceWithPublicAndHiddenConstructors(object _) { }
+
+            public ServiceWithPublicAndHiddenConstructors(object _, object _1) { }
+
+            internal ServiceWithPublicAndHiddenConstructors(object _, object _1, object _2) { }
+
+            private ServiceWithPublicAndHiddenConstructors(object _, object _1, object _2, object _3) { }
+        }
+
+        private class ServiceWithHiddenConstructor
+        {
+            internal ServiceWithHiddenConstructor(object _) { }
+        }
+
+        private class ServiceWithStaticConstructor
+        {
+            private ServiceWithStaticConstructor() { }
+
+            static ServiceWithStaticConstructor() { }
+        }
+    }
+}

Wingman/DI/ConstructorQueryProvider.cs

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+namespace Wingman.DI
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using System.Reflection;
+
+    internal class ConstructorQueryProvider : IConstructorQueryProvider
+    {
+        private readonly IConstructorFactory _constructorFactory;
+
+        public ConstructorQueryProvider(IConstructorFactory constructorFactory)
+        {
+            _constructorFactory = constructorFactory;
+        }
+
+        public IEnumerable<IConstructor> QueryPublicInstanceConstructors(Type type)
+        {
+            return type.GetConstructors(BindingFlags.Public | BindingFlags.Instance)
+                       .Select(_constructorFactory.CreateConstructor);
+        }
+    }
+}

Wingman/DI/IConstructorQueryProvider.cs

@@ -0,0 +1,10 @@
+namespace Wingman.DI
+{
+    using System;
+    using System.Collections.Generic;
+
+    internal interface IConstructorQueryProvider
+    {
+        IEnumerable<IConstructor> QueryPublicInstanceConstructors(Type type);
+    }
+}