Objects with a non nullable constructor argument (e.g. int) can now be mocked

Author: kevin-mcmanus

source/NSubstituteAutoMocker.UnitTests/NSubstituteAutoMocker.UnitTests.csproj

@@ -57,6 +57,7 @@
     <Compile Include="DocumentationSnippets\FirstExample.cs" />
     <Compile Include="NSubstituteAutoMockerTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="SamplesToTest\ClassWithPrimativeConstructors.cs" />
     <Compile Include="SamplesToTest\SealedClass.cs" />
     <Compile Include="SamplesToTest\ClassWithJustDefaultConstructor.cs" />
     <Compile Include="SamplesToTest\ClassWithPrivateDefaultConstructor.cs" />

source/NSubstituteAutoMocker.UnitTests/NSubstituteAutoMockerTests.cs

@@ -48,6 +48,15 @@ public void ClassUnderTestCanBeSealed()
                     new NSubstituteAutoMocker<SealedClass>();
                 Assert.IsNotNull(autoMocker.ClassUnderTest);
             }
+
+            [TestMethod]
+            public void PrimativeParameterTypesGetSetToDefaultValue()
+            {
+                NSubstituteAutoMocker<ClassWithPrimativeConstructors> autoMocker =
+                    new NSubstituteAutoMocker<ClassWithPrimativeConstructors>();
+                Assert.AreEqual(0, autoMocker.ClassUnderTest.IntValue);
+                Assert.AreEqual(null, autoMocker.ClassUnderTest.StringValue);
+            }
         }
 
         [TestClass]

source/NSubstituteAutoMocker.UnitTests/SamplesToTest/ClassWithPrimativeConstructors.cs

@@ -0,0 +1,23 @@
+namespace NSubstituteAutoMocker.UnitTests.SamplesToTest
+{
+    public class ClassWithPrimativeConstructors
+    {
+        public ClassWithPrimativeConstructors()
+        {
+        }
+
+        public ClassWithPrimativeConstructors(IDependency1 dependency1, IDependency2 dependency2, string stringValue, int intValue)
+        {
+            Dependency1 = dependency1;
+            Dependency2 = dependency2;
+        }
+
+        public IDependency1 Dependency1 { get; set; }
+
+        public IDependency2 Dependency2 { get; set; }
+
+        public string StringValue { get; set; }
+
+        public int IntValue { get; set; }
+    }
+}

source/NSubstituteAutoMocker/NSubstituteAutoMocker.cs

@@ -36,7 +36,7 @@ public NSubstituteAutoMocker(Type[] parameterTypes, Func<ParameterInfo, object,
             foreach (ParameterInfo info in parameters)
             {
                 Type type = info.ParameterType;
-                var constructorArg = Substitute.For(new Type[] { type }, null);
+                var constructorArg = CreateInstance(type);
                 if (parameterOverrideFunc != null)
                 {
                     constructorArg = parameterOverrideFunc(info, constructorArg);
@@ -48,6 +48,21 @@ public NSubstituteAutoMocker(Type[] parameterTypes, Func<ParameterInfo, object,
             ClassUnderTest = Activator.CreateInstance(typeof(T), args) as T;
         }
 
+        private object CreateInstance(Type type)
+        {
+            if (type.IsPrimitive)
+            {
+                return Activator.CreateInstance(type);
+            }
+
+            if (type == typeof(string))
+            {
+                return null;
+            }
+
+            return Substitute.For(new Type[] { type }, null);
+        }
+
         private ConstructorInfo MatchConstructorWithParameters(Type type, Type[] parameterTypes)
         {
             ConstructorInfo result;