What is Continuous Integration and Why Do We Need It II

So now that we have a very general understanding of what CI is the next step is to take a look at and see how it can work for us. On projects where sources control is used, we can have the system attempt to build before code is actually accepted into the repository. This will seriously cut down on the issues we had recently with someone forgetting to include a file, and failing the build for the next person who comes along. This is a good start but we can do better.

Over the last few months I have written and sometimes pulled articles about different utilities that can help us increase departmental productivity. Now it is time to take advantage of a few of them.

Lets Review:
FxCop
“FxCop is a free static code analysis tool from Microsoft that checks .NET managed code assemblies for conformance to Microsoft's .NET Framework Design Guidelines.” In short, this is an application that looks at the compiled code and verifies proper usage of coding standards set by Microsoft standards. This includes unused variables, misspellings in code, naming conventions and tons of others. Unfortunately, someone has to run it at specific intervals, generate a report and see to it that the changes are made, at that point it has to be run again, and the cycle starts over again. Imagine sending something back and forth over and over, that’s not to mention there is no way to identify the developer responsible for the offending code.

NUnit
NUnit is a popular testing framework for Microsoft .Net. Its main function is to allow developers to develop unit tests for their application.

A unit is the smallest testable part of an application. In object-oriented programming, the smallest unit is a method, which may belong to a base/super class, abstract class or derived/child class. A unit test is designed specifically to make sure a single unit is functioning as expected. Once developed, these unit tests could be run each time a change is made, thus identifying any new bugs that were introduced. Unfortunately, like these test only work if they are run and sometimes people forget to do this before checking their code in.

NAnt
NAnt is a free and open source software tool for automating software build processes. NANT executes its build process based on an XML build file. It can intern call command line instances of NUnit, FxCop, NDoc, and other tools during the build process. Configurations can be made so that if a unit test fails or a standard is not me the build is failed.

NAnt can also handle automated deployment, If the build is successful, it will generate a release build, zip it and place it in the releases folder for later deployment to the production server. All of this is kicked off by one command line call.

This is good, however, some still has to execute NAnt to build and verify their code before checking it in. This is where CI servers such as CruiseControl.Net and other come in. They bind to the source control product, such as Subversion, and on check-in download a fresh version of the code. From here they execute NAnt (including FxCop, NUnit, and others) if anything goes wrong the team receives an email and the code is rejected. The developer fixes whatever issue was reported and then the code is accepted. The better news is all these utilities are open source and free. Even better, I have already done most of the work to integrate everything together. The only thing I don’t have it the integration server mentioned above, because that will require some further assistance from the network team.