#27: throw exception when no public constructor is found

LightweightIocContainer/Exceptions/NoPublicConstructorFoundException.cs

@@ -0,0 +1,29 @@
+// // Author: Simon Gockner
+// // Created: 2019-11-04
+// // Copyright(c) 2019 SimonG. All Rights Reserved.
+
+using System;
+
+namespace LightweightIocContainer.Exceptions
+{
+    /// <summary>
+    /// No public constructor can be found for a <see cref="Type"/>
+    /// </summary>
+    internal class NoPublicConstructorFoundException : Exception
+    {
+        /// <summary>
+        /// No public constructor can be found for a <see cref="Type"/>
+        /// </summary>
+        /// <param name="type">The <see cref="Type"/> with no public constructor</param>
+        public NoPublicConstructorFoundException(Type type)
+            : base($"No public constructor for {type} found.")
+        {
+            Type = type;
+        }
+
+        /// <summary>
+        /// The <see cref="Type"/> with no public constructor
+        /// </summary>
+        public Type Type { get; }
+    }
+}

LightweightIocContainer/IocContainer.cs

@@ -300,7 +300,9 @@ namespace LightweightIocContainer
         private object[] ResolveConstructorArguments(Type type, object[] arguments)
         {
             //find best ctor
-            IOrderedEnumerable<ConstructorInfo> sortedConstructors = type.GetConstructors().OrderByDescending(c => c.GetParameters().Length);
+            List<ConstructorInfo> sortedConstructors = type.GetConstructors().OrderByDescending(c => c.GetParameters().Length).ToList();
+            if (!sortedConstructors.Any()) //no public constructor available
+                throw new NoPublicConstructorFoundException(type);
 
             NoMatchingConstructorFoundException noMatchingConstructorFoundException = null;
 

LightweightIocContainer/LightweightIocContainer.xml

@@ -161,6 +161,22 @@
             </summary>
             <param name="exception">The <see cref="T:LightweightIocContainer.Exceptions.ConstructorNotMatchingException"/></param>
         </member>
+        <member name="T:LightweightIocContainer.Exceptions.NoPublicConstructorFoundException">
+            <summary>
+            No public constructor can be found for a <see cref="P:LightweightIocContainer.Exceptions.NoPublicConstructorFoundException.Type"/>
+            </summary>
+        </member>
+        <member name="M:LightweightIocContainer.Exceptions.NoPublicConstructorFoundException.#ctor(System.Type)">
+            <summary>
+            No public constructor can be found for a <see cref="P:LightweightIocContainer.Exceptions.NoPublicConstructorFoundException.Type"/>
+            </summary>
+            <param name="type">The <see cref="P:LightweightIocContainer.Exceptions.NoPublicConstructorFoundException.Type"/> with no public constructor</param>
+        </member>
+        <member name="P:LightweightIocContainer.Exceptions.NoPublicConstructorFoundException.Type">
+            <summary>
+            The <see cref="P:LightweightIocContainer.Exceptions.NoPublicConstructorFoundException.Type"/> with no public constructor
+            </summary>
+        </member>
         <member name="T:LightweightIocContainer.Exceptions.TypeNotRegisteredException">
             <summary>
             The <see cref="T:System.Type"/> is not registered in this <see cref="T:LightweightIocContainer.Interfaces.IIocContainer"/>

Test.LightweightIocContainer/IocContainerTest.cs

@@ -62,6 +62,15 @@ namespace Test.LightweightIocContainer
             }
         }
 
+        [UsedImplicitly]
+        private class TestPrivateConstructor : ITest
+        {
+            private TestPrivateConstructor()
+            {
+
+            }
+        }
+
         [UsedImplicitly]
         private class TestByte : ITest
         {
@@ -303,6 +312,13 @@ namespace Test.LightweightIocContainer
             Assert.Throws<NoMatchingConstructorFoundException>(() => _iocContainer.Resolve<ITest>());
         }
 
+        [Test]
+        public void TestResolvePrivateConstructor()
+        {
+            _iocContainer.Register<ITest, TestPrivateConstructor>();
+            Assert.Throws<NoPublicConstructorFoundException>(() => _iocContainer.Resolve<ITest>());
+        }
+
         [Test]
         public void TestResolveFactory()
         {