I have the following structure:
abstract class AbstractClass{...}
interface Interface {...}
class MyClass : AbstractClass, Interface{...}
I want to create a proxy that would take MyClass as a target, could be cast to both - AbstractClass and Interface, however, it should only intercept Interface calls.
What's the best way to achieve that?
It took a bit of fiddling, but thanks to this SO question, I was able to intercept only interface methods.
Given:
public abstract class AbstractClass ...
public interface IBar ...
public class MyClass : AbstractClass, IBar ...
This interceptor should do what you want:
public class BarInterceptor : IInterceptor
{
public void Intercept(IInvocation invocation)
{
var map = invocation.TargetType.GetInterfaceMap(typeof(IBar));
var index = Array.IndexOf(map.TargetMethods, invocation.Method);
if (index == -1)
{
// not an interface method
invocation.Proceed();
return;
}
Console.WriteLine("Intercepting {0}", invocation.Method.Name);
invocation.Proceed();
}
}
My test code was:
var mc = new MyClass();
var gen = new ProxyGenerator();
var proxy = gen.CreateClassProxyWithTarget(typeof(MyClass), mc, new BarInterceptor());
((AbstractClass) proxy).GetString();
((AbstractClass) proxy).GetInt();
((IBar) proxy).GetItem();
Related
I have a problem with mocking cause it keep calling the original function. This is my demo code
First file is interface that contains the function that I want to mock.
public interface IDemoReplace
{
int FunctionToBeReplaced();
}
Second file is a class that actually has the implementation for the function
public class DemoReplace : IDemoReplace
{
public int FunctionToBeReplaced()
{
//this function contains sql query in my real project
return 1;
}
}
Third file is a class that I want to test
public class ClassToBeTested
{
public int TestThisFunction()
{
IDemoReplace replace = new DemoReplace();
var temp = replace.FunctionToBeReplaced();
return temp;
}
}
Last file is the test class
public class TestClass
{
[Fact]
public void TryTest()
{
using (var mock = AutoMock.GetLoose()) {
//Arrange
mock.Mock<IDemoReplace>()
.Setup(x => x.FunctionToBeReplaced())
.Returns(returnTwo());
var classToBeTested = mock.Create<ClassToBeTested>();
var expected = 2;
//Act
var actual = classToBeTested.TestThisFunction();
//Assert
Assert.Equal(expected, actual);
}
}
public int returnTwo() {
return 2;
}
}
This test will be failed with expected is 2 and actual is 1. When I tried to debug it doesn't call returnTwo but call the original function instead.
I am new to unit testing so what did I miss? Please be considered that the code above is only a demo of what is happened in my actual project. FunctionToBeReplaced is actually a function that execute and return record from database so I want to mock that function.
Thanks :)
This is a design issue. The subject under test is tight coupled to implementation concerns that make it difficult to isolation the subject so that it can be unit tested.
It (subject) is manually creating its dependency
IDemoReplace replace = new DemoReplace();
Ideally you want to explicitly inject dependencies. Those dependencies should also be abstractions and not concretions.
public class ClassToBeTested {
private readonly IDemoReplace dependency;
public ClassToBeTested(IDemoReplace dependency) {
this.dependency = dependency;
}
public int TestThisFunction() { ;
var temp = dependency.FunctionToBeReplaced();
return temp;
}
}
At run time, the implementation (or mock) can be injected, either purely, or via a container.
The test in the original example shown should now behave as expected.
public class TestClass {
[Fact]
public void TryTest() {
using (var mock = AutoMock.GetLoose()) {
//Arrange
var expected = returnTwo();
mock.Mock<IDemoReplace>()
.Setup(x => x.FunctionToBeReplaced())
.Returns(expected);
var classToBeTested = mock.Create<ClassToBeTested>();
//Act
var actual = classToBeTested.TestThisFunction();
//Assert
Assert.Equal(expected, actual);
}
}
public int returnTwo() {
return 2;
}
}
I am trying to get values from a class in another class which will be created dynamically and also methods too. Check these examples i've gone through .
InterfaceA.java
public interface InterfaceA{
public ArrayList<?> getValues();
}
ClassA.java / ClassB.java(consider another same class have value="World")
public Class A implements InterfaceA{
String value = "Hello";
public ArrayList<?> getValues(){
ArrayList<String> values = new ArrayList<String>();
values.add(this.value);
return values ;
}
}
ClassC.java
public Class C{
public void getValues(){
Object modelObject;
Method getValues;
modelObject = resolveClass("A"); // arg = classPath
getValues= modelObject.getClass().getMethod("getValues");
getValues.invoke(modelObject);
ArrayList<?> classValues;
// How to access Class A values from here
// I want to do These Lines
// classValue = get value from A/B.getValues() dynamically
}
private Object resolveClass(String className) throws
ClassNotFoundException, NoSuchMethodException, SecurityException,
InstantiationException, IllegalAccessException, IllegalArgumentException,
InvocationTargetException {
Class<?> loadClass = Class.forName(className);
Constructor<?> constructor = loadClass.getConstructor(String.class);
Object object = constructor.newInstance(new Object[] {});
return object;
}
}
How to access that method returned values as ArrayList<> mentioned in comments?
pseudo code...
Method m = .. getMethod("getValues");
Object o = m.invoke(modelObject);
ArrayList<?> classValues = (ArrayList<?>) o
you can find more info here
Can someone explain to me how to create an instance of this component in a Moq TestMethod? Here is the definition of the class. I need to test the ProcessAutomaticFillRequest method.
public class AutomaticDispenserComponent : IAutomaticDispenserComponent
{
private readonly Lazy<IMessageQueueComponent> _messageQueueComponent;
protected IMessageQueueComponent MessageQueueComponent { get { return _messageQueueComponent.Value; } }
public AutomaticDispenserComponent(Func<IMessageQueueComponent> messageQueueComponentFactory)
{
_messageQueueComponent = new Lazy<IMessageQueueComponent>(messageQueueComponentFactory);
}
public void ProcessAutomaticFillRequest(FillRequestParamDataContract fillRequestParam)
{
if (fillRequestParam.PrescriptionServiceUniqueId == Guid.Empty)
throw new InvalidOperationException("No prescription service was specified for processing fill request.");
if (fillRequestParam.Dispenser == null)
throw new InvalidOperationException("No dispenser was specified for processing fill request.");
var userContext = GlobalContext.CurrentUserContext;
var channel = string.Format(Channel.FillRequest, userContext.TenantId,
userContext.PharmacyUid, fillRequestParam.Dispenser.DeviceAgentUniqueId);
NotificationServer.Publish(channel, fillRequestParam);
}
Here is how I started my test, but I don't know how to create an instance of the component:
[TestMethod]
[ExpectedException(typeof (InvalidOperationException))]
public void FillRequestFailsWhenPrescriptionServiceUniqueIdIsEmpty()
{
// How do I create an instance of automatiqueDispenserComponent here
// since there is Func as constructor parameter?
var fillRequestParam = new FillRequestParamDataContract
{
PrescriptionServiceUniqueId = Guid.Empty
};
_automaticDispensercomponent.ProcessAutomaticFillRequest(fillRequestParam);
// ...
}
Updated the answer based on the comments below. You need to mock the Func parameter for the test.
[TestMethod]
[ExpectedException(typeof(InvalidOperationException))]
public void FillRequestFailsWhenPrescriptionServiceUniqueIdIsEmpty()
{
var mockMsgQueueComponent = new Mock<Func<IMessageQueueComponent>>();
var _automaticDispensercomponent = new AutomaticDispenserComponent
(mockMsgQueueComponent.Object);
var fillRequestParam = new FillRequestParamDataContract
{
PrescriptionServiceUniqueId = Guid.Empty
};
_automaticDispensercomponent.ProcessAutomaticFillRequest(fillRequestParam);
}
I'm trying to write this simple test:
var fixture = new Fixture().Customize(new AutoMoqCustomization());
var postProcessingAction = fixture.Freeze<Mock<IPostProcessingAction>>();
var postProcessor = fixture.Freeze<PostProcessor>();
postProcessor.Process("", "");
postProcessingAction.Verify(action => action.Do());
The Verify check fails.
The code for postProcessor.Process is
public void Process(string resultFilePath, string jobId)
{
IPostProcessingAction postProcessingAction =
postProcessingActionReader
.CreatePostProcessingActionFromJobResultXml(resultFilePath);
postProcessingAction.Do();
}
postProcessingActionReader is an interface field initialized through the constructor.
I'm expecting the test to pass but it fails, it turns out the instance of IPostProessingAction returned from the CreatePostProcessingActionFromJobResultXml method is not the same instance as returned from fixture.Freeze<>.
My expectation was that after freezing this Mock object it would inject the underlying mock of the IPostProcessingAction interface in every place its required as well as make all mock methods returning IPostProcessingAction return this same object.
Is my expectation about the return value of the mock methods incorrect?
Is there a way to change this behavior so that mock methods return the same frozen instance?
You need to Freeze the IPostProcessingActionReader component.
The following test will pass:
[Fact]
public void Test()
{
var fixture = new Fixture()
.Customize(new AutoMoqCustomization());
var postProcessingActionMock = new Mock<IPostProcessingAction>();
var postProcessingActionReaderMock = fixture
.Freeze<Mock<IPostProcessingActionReader>>();
postProcessingActionReaderMock
.Setup(x => x.CreatePostProcessingActionFromJobResultXml(
It.IsAny<string>()))
.Returns(postProcessingActionMock.Object);
var postProcessor = fixture.CreateAnonymous<PostProcessor>();
postProcessor.Process("", "");
postProcessingActionMock.Verify(action => action.Do());
}
Assuming that the types are defined as:
public interface IPostProcessingAction
{
void Do();
}
public class PostProcessor
{
private readonly IPostProcessingActionReader actionReader;
public PostProcessor(IPostProcessingActionReader actionReader)
{
if (actionReader == null)
throw new ArgumentNullException("actionReader");
this.actionReader = actionReader;
}
public void Process(string resultFilePath, string jobId)
{
IPostProcessingAction postProcessingAction = this.actionReader
.CreatePostProcessingActionFromJobResultXml(resultFilePath);
postProcessingAction.Do();
}
}
public interface IPostProcessingActionReader
{
IPostProcessingAction CreatePostProcessingActionFromJobResultXml(
string resultFilePath);
}
In case you use AutoFixture declaratively with the xUnit.net extension the test could be simplified even further:
[Theory, AutoMoqData]
public void Test(
[Frozen]Mock<IPostProcessingActionReader> readerMock,
Mock<IPostProcessingAction> postProcessingActionMock,
PostProcessor postProcessor)
{
readerMock
.Setup(x => x.CreatePostProcessingActionFromJobResultXml(
It.IsAny<string>()))
.Returns(postProcessingActionMock.Object);
postProcessor.Process("", "");
postProcessingActionMock.Verify(action => action.Do());
}
The AutoMoqDataAttribute is defined as:
internal class AutoMoqDataAttribute : AutoDataAttribute
{
internal AutoMoqDataAttribute()
: base(new Fixture().Customize(new AutoMoqCustomization()))
{
}
}
As of 3.20.0, you can use AutoConfiguredMoqCustomization. This will automatically configure all mocks so that their members' return values are generated by AutoFixture.
In other words, it will auto-configure your postProcessingActionReader to return the frozen postProcessingAction.
Just change this:
var fixture = new Fixture().Customize(new AutoMoqCustomization());
to this:
var fixture = new Fixture().Customize(new AutoConfiguredMoqCustomization());
I have a class with two constructors, both constructors have one parameter. Due to restrictions not worth explaining I cannot alter the constructors or use a descendent class.
I can't use unity to create instances of this class because Unity sees 2 constructors with the same number of parameters and complains that it doesn't know which to use, which is fair enough. So instead I create the instance myself and then try to use UnityContainer.BuildUp()
var result = constructorInfo.Invoke(new object[] { content });
UnitContainer.BuildUp(result);
The above code does not set any of my [Dependency] properties nor does it call an [InjectionMethod] if I use that instead.
var result = constructorInfo.Invoke(new object[] { content });
UnitContainer.BuildUp(typeOfObject, result);
This throws another exception about ambiguous constructors, even though I am not asking it to construct the instance.
Does anyone have any ideas?
Here is an example app
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Practices.Unity;
using System.Reflection;
namespace ConsoleApplication7
{
public interface IConstructorType1 { }
public interface IConstructorType2 { }
public interface INeedThisDependency { }
public class NeedThisDependency : INeedThisDependency { }
public class MyDomainObject
{
public MyDomainObject(IConstructorType1 constructorType1) { }
public MyDomainObject(IConstructorType2 constructorType2) { }
[Dependency]
public INeedThisDependency Needed { get; set; }
}
class Program
{
static void Main(string[] args)
{
IUnityContainer unityContainer = new UnityContainer();
unityContainer.RegisterType<INeedThisDependency, NeedThisDependency>();
//Try with type 1 constructor
ConstructorInfo constructorInfo1 = typeof(MyDomainObject).GetConstructor(new Type[] { typeof(IConstructorType1) });
MyDomainObject instance1 = CreateTheInstance(unityContainer, typeof(MyDomainObject), constructorInfo1, null);
//Try with type 2 constructor
ConstructorInfo constructorInfo2 = typeof(MyDomainObject).GetConstructor(new Type[] { typeof(IConstructorType2) });
MyDomainObject instance2 = CreateTheInstance(unityContainer, typeof(MyDomainObject), constructorInfo2, null);
}
//This is the only point I have any influence over what happens
//So this is the only place I get to change the code.
static MyDomainObject CreateTheInstance(IUnityContainer unityContainer, Type type, ConstructorInfo constructorInfo, object parameters)
{
var result = (MyDomainObject)constructorInfo.Invoke(new object[] { parameters });
//This will throw an ambiguous constructor exception,
//even though I am not asking it to construct anything
unityContainer.BuildUp(type, result);
//This will not build up dependencies
unityContainer.BuildUp(result);
if (result.Needed == null)
throw new NullReferenceException("Needed");
return result;
}
}
}
It's a bug in BuildUp, unfortunately.
Instead of calling BuildUp call this CallInjectionMethod helper.
public static class UnityContainerHelper
{
public static void CallInjectionMethod(this IUnityContainer unityContainer, object instance, params ResolverOverride[] overrides)
{
if (instance == null)
throw new ArgumentNullException("Instance");
var injectionMethodInfo = instance.GetType().GetMethods().Where(x => x.GetCustomAttributes(typeof(InjectionMethodAttribute), true).Any()).SingleOrDefault();
if (injectionMethodInfo == null)
return;
var parameters = injectionMethodInfo.GetParameters();
if (parameters.Length == 0)
return;
var dependencies = new object[parameters.Length];
int index = 0;
foreach (Type parameterType in parameters.Select(x => x.ParameterType))
{
dependencies[index] = unityContainer.Resolve(parameterType, overrides);
index++;
}
injectionMethodInfo.Invoke(instance, dependencies);
}
}