Why I Introduced Scala In Our Project

I don’t like Scala. And I think it has some bad and very ugly aspects that make it a poor choice for mainstream development.

But recently I still introduced it in our project. Not only that, but the team has no experience with Scala. And I’ll try to explain why that is not a bad idea.

  • First and most important – I followed my own advice and introduced it only in a small, side module. We didn’t have acceptance tests and we desperately needed some, so the JBehave test module was a good candidate for a scala project.
  • Test code is somewhat different from “regular” code – it is okay to be less consistent, more “sketchy” and to have hacks. On the other hand it could benefit from the expressiveness and lesser verbosity of scala, as tests are generally tough to read, especially in their setup phase. So Scala seems like a good choice – you can quickly write concise test code without worrying too much that you are shooting yourself in the foot in the long term, or that multiple team members do things in a different way (as Scala generously allows). Also, in tests you don’t have to face a whole stack of frameworks and therefore – all the language concepts at once (like implicits, partial functions, case objects, currying, etc.)
  • I didn’t choose a scripting language (or groovy in particular), because I have a strong preference for statically typed languages (yeah, I know groovy has that option for a couple of years now). I it should’ve been a JVM language, because we’d want to reuse some common libraries of ours.
  • It is good for people to learn new programming languages every now and then, as it widens their perspective. Even if that doesn’t change their language of choice.
  • Learning Scala I think can lead to better understanding and using of Java 8 lambdas, as in Scala you can experience them “in their natural habitat”.
  • I have previous experience with Scala, so there is someone on the team who can help

(As a side-note – IntelliJ scala support is now better than last time I used it (unlike the Eclipse-based Scala IDE, which is still broken))

If writing acceptance test code with Scala turns out as easy as I imagine it, then it can mean we’ll have more and betters acceptance tests, which is the actual goal. And it would mean we are using the right tool for the job, rather than a hammer.

3 thoughts on “Why I Introduced Scala In Our Project”

  1. Hi,

    From what you described I believe Kotlin (https://kotlinlang.org/) would be a better choice for your team.
    It is simpler than Scala still has all the goodies one would like to have in Java. And its IDE support is very good!

  2. My team and I have had excellent experience using Groovy and Spock in particular. Tests use code but (for the most part) read like a bdd spec. It also aligns very good with your own thoughts that “test code is somewhat different from ‘regular’ code – it is okay to be less consistent, more ‘sketchy’ and to have hacks”.

  3. Interesting idea. I wonder how the IDE supports cross language refactoring. Let’s say you rename a class from your production code in java, does the IDE rename also your class test written in Scala, Kotlin or Groovy?

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