Building sandcastles, part 3: Scala

(aka: And Now For Something Completely Different)

So, this is less about the continued experimentation in integration a bunch of SCM and CI systems, and more about random experimentation, because sometimes I just roll that way ;)

Pretty much on a whim, I brought Scala into the mix of technologies used. Following the recommendations of a couple of folk I've spoken to about this, I brought it in to the unit testing layer first, so that I can give it a go without too much impact on the actual written code. To be honest, it felt like a bit of a slog (though, having said that, I did manage to get the first unit test written and passing within an hour, after a beer, so I guess it can't be that hard).

First of all, we had to install Scala and the various IntelliJ plugins. That wasn't so bad. Second was to research how to run a JUnit test in Scala. Again, not too bad - suggestions are to use scalatest, and then have your unit tests extend the JUnitSuite class. Writing the unit test? No worries. Well ... not for the real simple ones, anyway. Running the test? Now that was the trick. First of all, you need to make sure that the version of scalatest you are using is compatible with the version of scala that you're using. Then you have to make sure that all the scala setup you did in the IDE also matches the version of scala you installed. Finally, you might need to tweak the build steps in the pom.xml file. Sadly, very few of the errors that get thrown when you have these things wrong make much sense.

For future reference (for myself, but maybe someone else will find this useful as well), this build configuration in maven seems to work quite well:

    <build>
        <plugins>
            <plugin>
                <groupId>org.scala-tools</groupId>
                <artifactId>maven-scala-plugin</artifactId>
                <version>2.15.2</version>
                <executions>
                    <execution>
                        <id>scala-compile</id>
                        <goals>
                            <goal>compile</goal>
                            <goal>testCompile</goal>
                        </goals>
                        <configuration>
                            <args>
                                <arg>-dependencyfile</arg>
                                <arg>${project.build.directory}/.scala_dependencies</arg>
                            </args>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

Something to be aware of is that the -make:transitive configuration argument seems to be redundant as of scala 2.11, and actually breaks the compilation. I've seen it mentioned in a couple of places, but taking it out made everything magically work for me... YMMV.

So anyway, I now have a very very simple test committed, which is currently passing. We'll see how things go as I try to rack up the complexity, and start on mocking out various interfaces.

Building sandcastles part 2

You know, that went pretty well, all things considered.

So, there are a couple of repositories up on GitHub now:
https://github.com/nihilogist/DiceEngine
https://github.com/nihilogist/PsychicWight

I managed to set up TeamCity without too many issues, and have that observing the two repositories.
It's also observing a given set of branches of the two repositories, so that a group of remote branches can also be built, and the results tracked.

I don't have a nexus installation running properly yet - that might be part of a larger experiment, but I can certainly see the benefits of the GitFlow workflow, where feature branches / release branches / etc. are the order of the day.

The next part of the project really should be to get the war file for the PsychicWight project up and running, and get some kind of automated / semi-automated deployment going.

But given that this took me just one day to set up, I think that it's certainly a viable approach to consider at the start of a project.

Hopefully there'll be time to revisit this next week.

Building sandcastles

(or: how do you practice at being an architect?)

Figuring out a different way of running a software project is kinda hard. Usually, you come into a project when everything is already set up and running, and you either go along with it, try to tweak it a little bit, or get the hell out. Starting from scratch isn't really one of the options.
Whilst I have opinions on some of the options, I don't really have a lot of experience at the way the different systems interact. I think that the best way of trying to sort this out is probably experience, but a problem with that is that building a large system with many interacting components is a hell of a lot of work.
So what I'm trying out is a small test project, with as many interacting components as I can, as well as a series of hoops to jump through that would usually only be present on a much larger project.

Project Sandcastle:

Going back to my absolute standard project, I'm going to build a dice roller. This time it's going to be a simple web based application, but I'm going to try and compartmentalise it as well.
In terms of infrastructure, I'm aiming for:

• an SCM system (git repository hosted on GitHub)
• a CI system (TeamCity, running locally)
• an artifact storage system (haven't decided yet, probably Nexus)

In terms of projects:

• a dice rolling engine (packaged as a jar file)
• a web application to interface with the engine (packaged as a war file, possibly with a built in server)