Suggested change to clean up CA warnings (#87)

Moq.AutoMock/AutoMocker.cs

@@ -229,7 +229,7 @@ public object CreateInstance(Type type, bool enablePrivate)
         /// <typeparam name="TService">The type that the instance will be registered as</typeparam>
         /// <param name="service"></param>
         public void Use<TService>([DisallowNull] TService service)
-            => Use(typeof(TService), service);
+            => Use(typeof(TService), service ?? throw new ArgumentNullException(nameof(service)));
 
         /// <summary>
         /// Adds an instance to the container.

Moq.AutoMock/Resolvers/Array.cs

@@ -0,0 +1,21 @@
+namespace Moq.AutoMock.Resolvers
+{
+#if NET45
+    //Array.Empty does not exist in net45
+    //This duplicates what was added to .NET Core
+    internal static class Array
+    {
+        public static T[] Empty<T>()
+        {
+            return EmptyArray<T>.Value;
+        }
+
+        private static class EmptyArray<T>
+        {
+#pragma warning disable CA1825 // this is the implementation of Array.Empty<T>()
+            internal static readonly T[] Value = new T[0];
+#pragma warning restore CA1825
+        }
+    }
+#endif
+}

Moq.AutoMock/Resolvers/MockResolver.cs

@@ -38,29 +38,24 @@ public void Resolve(MockResolutionContext context)
 
             var mockType = typeof(Mock<>).MakeGenericType(context.RequestType);
 
-            bool mayHaveDependencies = context.RequestType.IsClass 
+            bool mayHaveDependencies = context.RequestType.IsClass
                                        && !typeof(Delegate).IsAssignableFrom(context.RequestType);
-
-            object?[] constructorArgs;
+
+            //Invoke the Mock<T>(MockBehavior, params object[]) constructor
+            object?[] constructorArgs = new object?[2];
+            constructorArgs[0] = _mockBehavior;
+
             if (mayHaveDependencies)
             {
-                constructorArgs = context.AutoMocker.CreateArguments(context.RequestType);
+                constructorArgs[1] = context.AutoMocker.CreateArguments(context.RequestType);
             }
             else
             {
-#pragma warning disable CA1825
                 // Compiler complains about empty array literal, but I can't find an alternative that will compile.
-                constructorArgs = new object[0];
-#pragma warning restore CA1825
+                constructorArgs[1] = Array.Empty<object>();
             }
 
-            // Create single params argument to appease the compiler. If we don't do this, the
-            // compiler will try to pass an object[] to the constructor, which probably won't work.
-            var args = new object[constructorArgs.Length + 1];
-            args[0] = _mockBehavior;
-            constructorArgs.CopyTo(args, 1);
-
-            if (Activator.CreateInstance(mockType, args) is Mock mock)
+            if (Activator.CreateInstance(mockType, constructorArgs) is Mock mock)
             {
                 mock.DefaultValue = _defaultValue;
                 mock.CallBase = _callBase;