Htykuut

Part of my class initialize an object to an MLM ( which required a lot of setups and installations) what I need is to replace it
with a fake object to Do the same in an easy way,

For example how to test the following code with a fake object

// LMXProxyServerClass is the library in which need a lot of installation 

private readonly LMXProxyServerClass lmxProxyServer; 

And this is an example of one of the methods I use in

private bool CreateBindingWithoutPropagate(string attributeName, bool supervisory)

{

    bool creatingBindingResult = false;



    lock (mxAccessProxyLock)

    {



        if (!bindings.ContainsKey(attributeName))

        {

            try

            {

                logger.Debug("Adding item " + attributeName + " to bindings, not in list so add.");



                // Add the handle to the mapping

                lmxHandleToAttributeNameMapping.Add(attributeBinding.MxAttributeHandle, attributeName);



                if (supervisory)

                {

                     lmxProxyServer.DoSOmethingElse(yyyyyyyyyyyyyyyyyyyyyyy);

                    logger.Info(xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx);

                }

                else

                {



                    lmxProxyServer.DoSOmething(xxxxxxxx);

                    logger.Info(xxxxxxxxxxx);

                }



                // Add the binding to the list of bindings.

                bindings.Add(attributeName, attributeBinding);



                logger.Info("Creating binding for: " + attributeName);



                creatingBindingResult = true;



            }

            catch (System.UnauthorizedAccessException unauthorizedAccessException)

            {



                logger.Error("xxxxxxxxxxx", attributeName);

                throw ConvertExceptionToFault(unauthorizedAccessException);



            }

            catch (Exception ex)

            {

                throw ConvertExceptionToFault(ex);

            }

        }

    }



    return creatingBindingResult;

}

This library is third-party one so I have no control over it, so in testing I need to replace this object with fake one so I don't change a lot in the base code and ease the testing of other parts

Tightly coupling code to 3rd party implementation concerns make it difficult to unit test the code in isolation.

Instead encapsulate 3rd party implementation concern in an abstraction that can be mocked as needed when testing.

For example, create an abstraction of the 3rd party dependency, exposing only what is needed by your code.

public interface ILMXProxyServer {

    void DoSOmethingElse(...);

    void DoSOmething(...);

    //...

}

and have that explicitly injected into dependents via constructor injection.

public class MyClass {

    private readonly ILMXProxyServer lmxProxyServer; 



    public MyClass(ILMXProxyServer lmxProxyServer) {

        this.lmxProxyServer = lmxProxyServer;

    }



    //...other code omitted for brevity

}

The methods remain the same as they will call exposed members of the abstraction.

The run time implementation will wrap/encapsulate the 3rd party dependency

public class MyLMXProxyServerWrapper : ILMXProxyServer {

    // LMXProxyServerClass is the library in which need a lot of installation 

    private readonly LMXProxyServerClass lmxProxyServer; 





    public void DoSOmething(Something xxxxxxx){

         lmxProxyServer.DoSOmething(xxxxxxxx);

    }



    //...code omitted for brevity

}

With that refactor the code is now more flexible to be able to mock/fake the proxy server when testing in isolation using your mocking framework of choice or by rolling your own implementations specific for testing.