Parameterized Unit Tests in Scala (with JUnit4)

That's quite a nuisance, but it works. Two important things I discovered: companion object must come after test class, the function returning the parameters must return a collection of arrays of AnyRef (or Object). arrays of Any won't work. That the reason I use java.lang.Integer instead of Scala's Int.

import java.{util => ju, lang => jl}
import org.junit.Test
import org.junit.runner.RunWith
import org.junit.runners.Parameterized
import org.junit.runners.Parameterized.Parameters

@RunWith(value = classOf[Parameterized])
class JUnit4ParameterizedTest(number: jl.Integer) {
    @Test def pushTest = println("number: " + number)
}

// NOTE: Defined AFTER companion class to prevent:
// Class com.openmip.drm.JUnit4ParameterizedTest has no public
// constructor TestCase(String name) or TestCase()
object JUnit4ParameterizedTest {

    // NOTE: Must return collection of Array[AnyRef] (NOT Array[Any]).
    @Parameters def parameters: ju.Collection[Array[jl.Integer]] = {
        val list = new ju.ArrayList[Array[jl.Integer]]()
        (1 to 10).foreach(n => list.add(Array(n)))
        list
    }
}

The output should be as expected:

Process finished with exit code 0
number: 1
number: 2
number: 3
number: 4
number: 5
number: 6
number: 7
number: 8
number: 9
number: 10

You are probably better off with ScalaTest or Specs. The latter definitely supports parameterized tests, and is widely used in the Scala community. JUnit's syntax for parameterized tests is pretty horrible, and its reliance on static declarations won't make your task easier in Scala (probably you need a companion object).