Visual Studio 2010 (Rosario) - First Impressions (1)

I've just gone through the pain of downloading each of the files required to extract the Visual Studio 2010 aka Rosario September CTP VPC. Why couldn't they use the Microsoft Download Manager??

Anyway, first things first, I opened Visual Studio 2010 and went to the New Project dialog. The first thing that I noticed was that the MVC Framework is missing. Now I'm not surprised as it is yet to be released, and I don't doubt that it'll make it to the final release, but it's a bit disappointing all the same as it means I'll have to settle for bad old asp.net when I get to the web stuff.

The new options that stand out to me are the WiX project options, nice to see that getting shipped with Visual Studio, and Modelling Projects (which currently just has an empty project). Being curious to see what this is this Modelling Project is my first point of call.

Choosing to create a new Empty Modelling Project presents me with this:

I get a Model Explorer on the left and in the Solution Explorer I can see that I have been given a ModelDefinition folder. Opening this folder reveals a single file - ModelDefinition.uml. When I right click and choose to Add a File I have a number of different types of model presented to me. These are:

• Activity Diagram
• Component Diagram
• Layer Diagram
• Logical Class Diagram
• Sequence Diagram
• Use Case Diagram

My first thoughts are that it's a useful enough set of diagrams to work from. I'm a little surprised not to see a State Machine available, especially given the way that Workflow Foundation might have some obvious synergy with this type of model. There's also no sign of support for OCL, but I'm less surprised by this (and certainly not disappointed). I've also never come across a 'Layer Diagram' diagram before, and a quick look at the OMG UML Superstructure specification doesn't seem to mention it - though maybe I just can't spot it there. That being the case the Layer Diagram seems to be like a logical place to start playing.

The Layer Diagram seems to be about showing the various layers that will make up an application, and the dependencies between those layers. It has 3 patterns available out of the box that you can drag and drop on; 3 layer, 4 layer, and MVC. Seeing the MVC pattern there is nice, but I'm not sure how useful this is. How many applications end up wth just these three layers, hmmm, maybe if you're following the ActiveRecord pattern but otherwise you're likely to have some form of Repository/DAO layer I would think. So being a generally DDD guy the first 'layer' pattern that I've tried to put together follows an Onion/Hexagonal pattern.

Ok, so why is this better than what I can do with basic shapes in Visio. Well, one thing is that I can specify acceptable namespaces for each layer (and unacceptable ones), drag and drop projects onto the layer from the solution explorer, which associates the project with that layer. Now if I specify an invalid namespace in a class file then when the model is validated I get a series of errors telling me of the bad namespace naming. Now I've got to say that this feature on its' own is not exactly compelling. Yes, I like to ensure compliance to conventions across the dev team(s) that I work with, but I wouldn't create this diagram just for that purpose. Also, I haven't created this in the way that I normally would - I typically follow the examples provided by Kyle Bailey and Jeffrey Palermo. With this I wasn't sure of how to represent the utilities that would normally be present. I was also tempted to break some of the layers up and make this more like a project diagram, a temptation I resisted. Another feature I spotted was the ability to put layers inside of layers, so I could have dropped the MVC layer inside of my UI layer, if I did though then suddenly for me my UI layer would contain layers that are typically just folders inside of a project for me. Maybe I'm just not 'getting it', or I'm just not working on big enough systems)(though I'd question the ability to manage the complexity of a system with many more layers that represented collections of projects. I guess that when more features are added to this type of model then its' real potential for usefulness will become clear. At the moment I'm not really sold on it.

Looking at the xml that is used to represent the diagram behind the scenes makes me worried about the potential merge conflicts that might emerge should two people ever work on the same artifact at the same time. This is something that I think I'll definitely check out soon as it has a real impact on how practical something like this can be when you are working as a part of a team.

Next up is a sequence diagram. These are diagrams that I use a lot and typically I use Enterprise Architect to create them. I've tried using Visio and always just end up incredibly frustrated at the lack of even basic support for this type of artifact.

Well, the less than headline news is that this is nowhere near being Enterprise Architect so Sparx Systems can sleep easy for at least another release of Visual Studio. On dragging a lifeline on to the surface I am able to specify that I am dealing with an actor. I am not able to specify that it is a boundary however which is something that I use quite a lot. Support for messaging seems to be ok with synchronous and asynchronous messages easily added into the diagram. Self messaging is also nicely catered for. Creating objects is handled ok, I prefer it when the arrow points to the box rather than to the lifeline itself, but I'm not that fussy. I can't see that it is possible to denote deletion from another object but I guess that given garbage collection in managed applications this doesn't ever really happen as such. I also can't see that it's possible to add constraints (OCL or otherwise). Frames seem to be supported through the 'Interaction Use' which I am assuming is an interaction frame.

Currently Guard clauses don't seem to be possible which is a bit of a miss. This is probably because the only operator currently available for the interaction frame is 'ref' and I'd need at least support for 'alt', 'loop', 'opt', and 'par' before I could make much practical use of the sequence diagram facility. Still there's at least a year to go before release so I hope that they do expand this feature. Also it would be nice to be able to drag a class on to the designer and then use it. With Enterprise Architect I can reverse my code base into a model and then get to select from classes and their available methods when I am putting the model together. I don't expect this feature to be comparable to Enterprise Architect when it releases, but if it is to be more than a gimmick there is a very long way to go. The good news for Microsoft (I think) is that I'm already more inclined to use this CTP than the UML features of Visio 2007 (which are just bloody awful), they may not be as feature rich yet, but they already feel more right.

Another post to follow as I continue to explore this CTP.

Simian - A Copy and Paste Code Hunter Killer!

In my new(ish) job I have to look after a legacy application with a very large code base. Over the years this has been developed with a lot of copy and paste coding practices. This is a significant contributor to our 'technical debt' and certainly increases the costs of ownership associated with the application, adversely affecting troubleshooting, maintenance, and new feature development.

I have already been making good use of NDepend and Resharper to assist with refactoring, and still have hopes that we will invest in Ants Profiler, but I was missing a tool that would nicely identify for me where copy and paste coding might have occurred. After a little Googling I discovered Simian.

This great little command prompt utility will analyse a Visual Studio solution and spot instances of the same code existing in multiple places. It was really simple to integrate in to the Visual Studio IDE and will make a big difference to my team going forward. Now when working on a piece of code we can quickly check to see if it exists else where and refactor accordingly. This new visibility is going to be invaluable as we move forward and attempt to bit by bit pay back the technical debt.

I found a great blog post by a chap from Conchango that showed how to integrate it with Visual Studio, but in the end I mainly just used the, plenty good enough, documentation that ships with it.

The line that I am currently using to have this tool scan my solution is:

-formatter=vs:c:\temp\buks_simian.log -language=cs $(ProjectDir)/../**/*.cs $(ProjectDir)/../**/*.aspx $(ProjectDir)/../**/*.js

What this does is:

-formatter=vs:c:\temp\buks_simian.log (specify that the output should be dumped to a file on my C drive and formatted for Visual Studio)

-language=cs $(ProjectDir)/../**/*.cs (specify that the all the files that are children of the parents of my current project directory should be searched (this is recursive thanks to the /**/))

$(ProjectDir)/../**/*.aspx $(ProjectDir)/../**/*.js (like above but also look at the aspx and js files too).

The reason why I am starting from the ProjectDirectory and then going up a level before initiating a recursive scan, rather than just using the Solution directory is that my Solution files live outside of the structure of the projects, ensuring that they don't end up source controlled.

Resharper 4 Bug with 'Use Format String'

I'd like to say first that I really, really like Resharper 4.0 and have made it my mission to persuade my boss to buy it for all of the Dev's where I work. I got my copy free at a NxtGenUG Southampton meeting and it continues to make my life as a developer easier.

But...

I've come across a small bug in Resharper 4.0 today, so I thought that I'd share so that others become aware.

Real code has been changed to protect the innocent (and because it belongs to my employer).

Start off with a StringBuilder.Append statement that uses the '+' operator to concatenate a string with an object. Why an object, well because that's what the code I'm working with has, not ideal, but that's working with legacy code for you sometimes.

Of course, using the Append statement with string concatenation isn't ideal practice either and what I'd like is to change it to an AppendFormat call. Now Resharper makes this very, very (seductively) simple.

Here's my example code before I let Resharper do its' thing:

Here's Resharper offering to do its' thing:


Here's the code that results:

The important line to note is that we now have:

stringBuilder.AppendFormat("{0} likes Resharper.", (object[])canBeCastToString);

Note the unnecessary cast to an object array. Because of this we now get the error:

System.InvalidCastException: Unable to cast object of type 'System.String' to type 'System.Object[]'.

The solution is just to get rid of the superfluous cast to Object[].

I still really, really like Resharper 4.0.

Resharper 4.0 and Lambda Expressions

Now I'm fairly new to the wonderful world of Resharper, so barely a day goes by where I don't discover something new about it, or through it. But today I found a feature that just made me want to share about it straight away.

Let me set the scene.

I'm coding a Lambda expression for use as a predicate and when finished I notice the now familiar little light bulb. Hmmm I thought, now what could Resharper be wanting to tell me about my code?

(real code replaced throughout to protect the innocent)

That's right Resharper is offering to convert my Lambda to either an anonymous method or a statement! So let's see what it does to the code if I choose these options.

Well If I choose the option 'Lambda expression to statement it turns my code into this:

Note with this option I am given the choice to now convert on to an expression, or to an anonymous method.

If I choose the option 'To anonymous method' my code looks like this:

Note that it is offering to convert my code back to a lambda

If I choose the 'Lambda expression to anonymous method' option and place the caret in to the delegate keyword then I get a different option however.

This time the options include one to convert my anonymous method to a named method. Choosing this does what you will no doubt expect. It creates named method.

private static bool NewPredicate(Person p)
{ return p.Name == "Sue"; }

and changes my code to read:

Person sue = people.Find(NewPredicate);

Actually I added the prefix new, as Resharper just put Predicate, but you get the idea. Of course, Resharper now gives me the option to inline my Predicate as either an anonymous method, or as a Lambda.

Neat huh!

Choosing to inline as an anonymous method acts as I would expect, and puts the code back to be the same as the anonymous version above. Choosing to inline as a Lambda however a have a tiny, tiny gripe with.

As you can see above, Resharper has placed the target variable within brackets. Still, at least Resharper knows that it shouldn't have done this, as it offers to remove them!

What I really, really like most about this, and made me want to blog about it, it that it very neatly highlights some of the evolution of C# from version 1 with its' named delegates (though of course we didn't have delegate comparisons then), through version 2, with its' anonymous methods, through to the current version 3 with its' Lambda goodness.