Setting up a Scala project in Eclipse, together with JUnit & Scalatest

Question

I have recently completed the Scala course on Coursera, and since then I have been looking forward to getting my hands dirty with Scala again. I have written code for some years but I neither educated to be nor work as a programmer, so it took me a while to get a good opportunity but now that I have some time to invest and a good project to work on it's time...

Except I can't seem to get things set up properly, which I find really frustrating. I have OpenJDK 1.7.0_25 running on my Linux machine. I have downloaded and installed the Bundle Scala IDE build for Eclipse (just like we used in the course). And I got ScalaTest both as a jar file and the Eclipse plug-in.

I have a simple project (so far) and no matter what I do I can't seem to get my builds and tests in order. First off how exactly am I supposed to set up my project so that my classes and tests are actually run properly? All the assignments we got were projects that had the same structure, so do I have to have:

project
  |--src
      |--main
          |--scala
      |--test
          |--scala

structure? If so why is it not the default way the project is setup when I create a new project? Do I create these folders manually, as packages or as source folders? The whole thing gets pretty murky..

I should mention that I tried to "Mavenize" the project using the contextual menu in Eclipse, added my ScalaTest dependency. The first thing that happens is that I get compile errors, at every point of dependency in my code. So clearly the library is not visible, in other words Maven does not seem to be doing much of management. I thought the whole point of Maven was to get and maintain dependencies as the project evolves. I concluded that I do not fully understand the way Maven works and thus I eventually gave up on Maven, once again, and went back to doing things manually.

Secondly, I can't seem to run my tests; the Run As... menu item does not include ScalaTest as it's mentioned in the documentation of ScalaTest Eclipse Plug-in. I have double checked that the plugin is installed. If I instead try to run using JUnitRunner then my tests are not recognized as valid tests. I have JUnit and ScalaTest on my build path, so it's got to be something else.

I suppose my overarching question is as follows:

given the Scala IDE build of Eclipse and ScalaTest, just exactly how am I supposed to set up my project (in Eclipse) so that I can just focus on writing my code and testing it, and hopefully not have any other headaches?

I work alone, and this project is not a product I need to deliver to some client. In other words I do not need to adhere to strict professionalism here. Honestly I just want to be able to code, get better acquainted with Scala and hopefully build a small data analysis tool that I will be using from time to time.

Thanks in advance!

Answer 1

Try using the sbt eclipse plugin: https://github.com/typesafehub/sbteclipse

This is of course assumes that you use sbt as you build tool. If you don't at the moment you can find instructions on installation and usage here: http://www.scala-sbt.org/

Personally I've been using typesafe giter8 template (https://github.com/typesafehub/scala-sbt.g8) to setup my Scala projects, and then I use the sbt plugin mentioned above to generate eclipse project files.

Answer 2

Scala is somewhat Maven-based (sometimes implicitly), that's why you use that structure.

The easiest way I think is to create a simple Sbt/Maven POM and create the Eclipse project configurations (like with sbt eclipse). There you can set the dependencies (like the actual version of JUnit, Scalatest to use), so you can use the ScalaTest plugin easily.

In case of other issues, feel free to ask at the ScalaTest mailing list, Chee Seng and Bill Venners can help you a lot there.

Answer 3

The Scala IDE website has a full documentation on how to run unit testing frameworks with the IDE, have a look ! If you find missing elements, the bug tracker of the scala-IDE project is here.