I thoroughly agree with this post by Jeff:
http://www.codinghorror.com/blog/archives/000895.html
The most valuable things I learnt at uni were the ability to critically think, analyse situations and "learn how to learn". Although I really don’t use a lot of my studies on a daily basis I believe it helps me every day mainly in R&D
Thursday, June 28, 2007
Wednesday, June 27, 2007
NHibernate gotcha for Generated files
To save yourself repeated banging of you head make sure you HBM.XML file are embedded resources in the nhibernate project, otherwise how is nhibernate going to find these mappers....d'oh!
This highlights a point: Its nice to generate what you can. Hell, if you have already written the database tables, why not Gen the majority of your data access? You still however, have to know what is going on under the hood, whether its nhibernate, other ORM or straight ADO.Net. Otherwise how fix you fix lower level problems when you run in to them...
This highlights a point: Its nice to generate what you can. Hell, if you have already written the database tables, why not Gen the majority of your data access? You still however, have to know what is going on under the hood, whether its nhibernate, other ORM or straight ADO.Net. Otherwise how fix you fix lower level problems when you run in to them...
Tuesday, June 26, 2007
TDD still not with the masses?
Recently I have been a contractor on a project that I have been given I little bit of grief (perhaps light heart, perhaps not) regarding the number of unit tests I have written in comparison to the production code I have submitted. Upon talking to some external mates in the development field there still seems to be some confusion as to why to test, how to test and when to test. I will happily admit that I am no TDD guru and am relatively new to the having only really being diligent about unit tests over the last year or so.
I did want to share some of my reasons, that may not be so text book, for using TDD. I will start with aspects of TDD, that on my most recent project, I have directly benefited from:
Define the Functionality of the Module
In the last project requirements were somewhat lose, so writing the unit test help the guy with the business know how and myself knuckle out what exactly we wanted these blocks of code to do. The people that will have to maintain my code as I move to the next project will probably find this module easier to maintain because of the reasonably well named and documented tests that are in place, meaning reduced ongoing cost of the code base.
Ability to Refactor with Confidence
As I was receiving information about the requirements in a piecemeal fashion, I was forced to write code for the functionality as I got it. This quickly became quite a large amount of code which later we found had aspects replicated across multiple classes. Refactoring these classes to strategies that inherited from a base strategy which inturn implemented an interface with the real business logic held in a handful of delegates meant we reduced the lines of code by 73%. As we refactored we made sure the entire block of unit tests still passed. The code is now a fraction of the size, very easy to read and maintain, fast and still fulfils the requirement set forth by the business. Refactoring all that code that took weeks to write was done in a day, in confidence because the unit tests were written up front.
Reduction of “Gold Plating”
In some case I get carried away and start writing things that I haven’t got a test for, because they may be needed in the future. This is by and large a bad habit of mine, I don’t get paid to gold plate, I get paid to provide a quality solution to a defined problem, even if that problem is not very well defined!
How has TDD helped? If it was not being covered by a unit test, it either needs to be or it gets removed. 9/10 it get removed as the tests are written first and they define the functionality.
Code Confidence
Although test don’t prove you code is good (see TDD Anti Patterns) it odes show that I have thought about what I am doing and give other developers or interested parties a direct view at what my code does. Most of my test methods are named so it is pretty obvious what they do, sure some get pretty long but I can find a unit for a module that I wrote months ago pretty bloody quick and figure out with in seconds the exact functionality. This is especially helpful if you have no BA support or business requirement documentation (yes it happens). Not only am I more confident in my code but I am more confident in other code if it is unit tested.
Encourages Correct Separation of Concerns
Especially when using mocks it becomes apparent when projects are starting to take on more functionality than they should.
Up-to-date Code
As I am writing tests for my code, as I go, I find that I am more likely to be within minutes of a previous compiling working solution. Formerly I used to go on tangents and write pages of code which may have been in a state far removed from a submittable state. If for some reason I was asked to shift on to other functionality I would have to shelve changes roll back and then work on something else. If I ever cmame back to that code I often had no idea where I was up to. Now I know exactly where I am up to… the method that breaks the unit tests! It is also more likely that I wouldn’t have to shelve as it is probably only a minute away from being in a compilable stae that I could check in to source control.
Easier to Make Changes
There have been some instances where the business requirements, or my understanding of them have been (a little bit) off. Having the test there means I can modify the test to assert correct assumption run the tests, see it fails and then make an isolated change in the code. As the test marry up nicely to the code the place where the change is required is very easily found and fix. ..Run test…. Pass test… Check in.
So how do i go about it? Well my"why" is covered above. For more reason check out http://www.testdriven.com or any other of the plethora of sites and books dedicated to TDD... as for the when and how...
When to test?
Before you have even written the functionality! Define what you want the method to achieve. You will probably find your self writing multiple tests per method and test fixtures are generally a lot larger than the class they test, bu the time you save in reduced debugging time and easier maintenance is well worth it.
How to test?
There are heaps of tools to use and can be a personal thing. Currently I am using TestDriven.Net with NCover and NUnit as well as ReSharper & Rhino mocks. As ReSharper is the only tool here I have paid for there is no reason not to get these widely used tools (I probably should throw some money at Testdriven.net).
Try to get a test project for each business project and a test fixtures should closely marry up with the projects classes. I don’t test minor thing like properties… there should be reason for the test!
Most frameworks now are very open to TDD, so there is very little reason not to use it. Right up to UI patterns, all but the view are very easy to test and mock. And as the view is completely stupid it should not have a lot scope for error.
So start testing; the initial growing pains are well worth it.
RhysC
I did want to share some of my reasons, that may not be so text book, for using TDD. I will start with aspects of TDD, that on my most recent project, I have directly benefited from:
Define the Functionality of the Module
In the last project requirements were somewhat lose, so writing the unit test help the guy with the business know how and myself knuckle out what exactly we wanted these blocks of code to do. The people that will have to maintain my code as I move to the next project will probably find this module easier to maintain because of the reasonably well named and documented tests that are in place, meaning reduced ongoing cost of the code base.
Ability to Refactor with Confidence
As I was receiving information about the requirements in a piecemeal fashion, I was forced to write code for the functionality as I got it. This quickly became quite a large amount of code which later we found had aspects replicated across multiple classes. Refactoring these classes to strategies that inherited from a base strategy which inturn implemented an interface with the real business logic held in a handful of delegates meant we reduced the lines of code by 73%. As we refactored we made sure the entire block of unit tests still passed. The code is now a fraction of the size, very easy to read and maintain, fast and still fulfils the requirement set forth by the business. Refactoring all that code that took weeks to write was done in a day, in confidence because the unit tests were written up front.
Reduction of “Gold Plating”
In some case I get carried away and start writing things that I haven’t got a test for, because they may be needed in the future. This is by and large a bad habit of mine, I don’t get paid to gold plate, I get paid to provide a quality solution to a defined problem, even if that problem is not very well defined!
How has TDD helped? If it was not being covered by a unit test, it either needs to be or it gets removed. 9/10 it get removed as the tests are written first and they define the functionality.
Code Confidence
Although test don’t prove you code is good (see TDD Anti Patterns) it odes show that I have thought about what I am doing and give other developers or interested parties a direct view at what my code does. Most of my test methods are named so it is pretty obvious what they do, sure some get pretty long but I can find a unit for a module that I wrote months ago pretty bloody quick and figure out with in seconds the exact functionality. This is especially helpful if you have no BA support or business requirement documentation (yes it happens). Not only am I more confident in my code but I am more confident in other code if it is unit tested.
Encourages Correct Separation of Concerns
Especially when using mocks it becomes apparent when projects are starting to take on more functionality than they should.
Up-to-date Code
As I am writing tests for my code, as I go, I find that I am more likely to be within minutes of a previous compiling working solution. Formerly I used to go on tangents and write pages of code which may have been in a state far removed from a submittable state. If for some reason I was asked to shift on to other functionality I would have to shelve changes roll back and then work on something else. If I ever cmame back to that code I often had no idea where I was up to. Now I know exactly where I am up to… the method that breaks the unit tests! It is also more likely that I wouldn’t have to shelve as it is probably only a minute away from being in a compilable stae that I could check in to source control.
Easier to Make Changes
There have been some instances where the business requirements, or my understanding of them have been (a little bit) off. Having the test there means I can modify the test to assert correct assumption run the tests, see it fails and then make an isolated change in the code. As the test marry up nicely to the code the place where the change is required is very easily found and fix. ..Run test…. Pass test… Check in.
So how do i go about it? Well my"why" is covered above. For more reason check out http://www.testdriven.com or any other of the plethora of sites and books dedicated to TDD... as for the when and how...
When to test?
Before you have even written the functionality! Define what you want the method to achieve. You will probably find your self writing multiple tests per method and test fixtures are generally a lot larger than the class they test, bu the time you save in reduced debugging time and easier maintenance is well worth it.
How to test?
There are heaps of tools to use and can be a personal thing. Currently I am using TestDriven.Net with NCover and NUnit as well as ReSharper & Rhino mocks. As ReSharper is the only tool here I have paid for there is no reason not to get these widely used tools (I probably should throw some money at Testdriven.net).
Try to get a test project for each business project and a test fixtures should closely marry up with the projects classes. I don’t test minor thing like properties… there should be reason for the test!
Most frameworks now are very open to TDD, so there is very little reason not to use it. Right up to UI patterns, all but the view are very easy to test and mock. And as the view is completely stupid it should not have a lot scope for error.
So start testing; the initial growing pains are well worth it.
RhysC
Monday, June 25, 2007
Win form UI dev
<Disclamer>I suck at Win forms dev, the only time I use it is for test rigs and for uber basic (in terms of UI) CE apps </Disclamer>
I have been trying to set 3 total values to right align at the decimal point in a panel on a WinFom app. It proves to be not as trivial as I expected.
I have to place each of them in a panel and then dock these labels to the right side of the each holder panel. What over kill! Why can’t the AutoSize and Anchor functionality do this for me? Oh well…
I have been trying to set 3 total values to right align at the decimal point in a panel on a WinFom app. It proves to be not as trivial as I expected.
I have to place each of them in a panel and then dock these labels to the right side of the each holder panel. What over kill! Why can’t the AutoSize and Anchor functionality do this for me? Oh well…
WS... not so interoperable..
from Udi:
http://feeds.feedburner.com/~r/UdiDahan-TheSoftwareSimplist/~3/127874396/
"...So imagine my surprise when we “Web Service-ized” a bunch of Java components that exposed just that kind of interface, and it didn’t work. After mucking around for almost the whole day, we started returning to basic principles. We started throwing out parameter after parameter, structure after structure, until we were left with something that should have just worked:
string SomeFunction(char c);
But it didn’t.
This was ridiculous. If Web Services couldn’t give me interoperability at this most basic level, I swore that the whole thing must have been a conspiracy. After some ill-mannered googling, I found out that:
The Java char datatype is not supported because of an omission in XML Schema..."
http://feeds.feedburner.com/~r/UdiDahan-TheSoftwareSimplist/~3/127874396/
"...So imagine my surprise when we “Web Service-ized” a bunch of Java components that exposed just that kind of interface, and it didn’t work. After mucking around for almost the whole day, we started returning to basic principles. We started throwing out parameter after parameter, structure after structure, until we were left with something that should have just worked:
string SomeFunction(char c);
But it didn’t.
This was ridiculous. If Web Services couldn’t give me interoperability at this most basic level, I swore that the whole thing must have been a conspiracy. After some ill-mannered googling, I found out that:
The Java char datatype is not supported because of an omission in XML Schema..."
Tuesday, June 19, 2007
Translating Geek-Speak to Suit-Speak
A colleague and I were talking of the technical debt being incurred on the project we are currently consulting for, when I commented its a bit of a wanky term. CDS quickly reminded me that its a term probably used when a Dev, Architect, consultant is talking to someone in more of a business role and that we have to talk in their terms, i.e. ROI, Debt, Interest, Inflation... i.e "$$$ speak".
It was a good reminder that in times when you need to emphasise crucial points it probably best to talk in a language the other party will actually understand, and therefore "get" the significance of the problem. It is then up to them to make a more informed business decision from there.
It was a good reminder that in times when you need to emphasise crucial points it probably best to talk in a language the other party will actually understand, and therefore "get" the significance of the problem. It is then up to them to make a more informed business decision from there.
Recurring events and SQL
Working with "Recurring events" is proving to be interesting. I am trying to create a framework that will allow for adding recurring events (such as training times from a given team) with reasonable flexablity, reasonable speed in creating and querying and still reasonably maintainable.
It looks like there will have to be a trade off some where.
I am using the concepts from Fowler's recurrence essay and extending that. Putting that into a Database pushes me to wanting to use the XML datatype... the more i think about it tho, the less I like it as the querying power would be, well, not so good.
If I use table to map to the temporal expression it could get messy quick too. Either way i am wanting the abiltiy to create db entry for an instance of the recurrence so people can leave note etc for specific occurances...
this is going to be interesting... only post i could find so far has been
http://forums.devx.com/showthread.php?threadid=136165
I may have to step back again and relook at what i'm doing ;)
It looks like there will have to be a trade off some where.
I am using the concepts from Fowler's recurrence essay and extending that. Putting that into a Database pushes me to wanting to use the XML datatype... the more i think about it tho, the less I like it as the querying power would be, well, not so good.
If I use table to map to the temporal expression it could get messy quick too. Either way i am wanting the abiltiy to create db entry for an instance of the recurrence so people can leave note etc for specific occurances...
this is going to be interesting... only post i could find so far has been
http://forums.devx.com/showthread.php?threadid=136165
I may have to step back again and relook at what i'm doing ;)
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