Combine mocks and ordinary tests within one test class in Scala - scala

Question

Code
Test
package com.utrecht.numbersequences
import org.scalatest.FunSuite
import org.scalatest.BeforeAndAfter
import org.scalatest.mock.MockitoSugar
import org.mockito.Mockito._
class NumberSequencesTests extends FunSuite with BeforeAndAfter with MockitoSugar {
test("randomInteger") {
val m = mock[NumberSequences]
when(m.randomInteger(5)).thenReturn(5)
assert(5 === m.randomInteger(5))
}
test("squareRoot") {
assert(NumberSequences.squareRoot(25) === 5)
}
}
Main
package com.utrecht.numbersequences
import scala.collection.immutable.Stream.consWrapper
class NumberSequences {
def randomInteger(a: Int) : Int = {
scala.util.Random.nextInt(a) + 1
}
def squareRoot(a: Double) : Double = {
math.sqrt(a)
}
}
Outcome
Expected
> test
[info] NumberSequencesTests:
[info] - randomInteger
[info] - squareRoot
[info] Passed: Total 2, Failed 0, Errors 0, Passed 2
[success] Total time: 1 s, completed Aug 10, 2014 11:46:44 AM
>
Current
In order to test squareRoot the NumberSequences class needs to be changed into an object. Once this has been done, the squareRoot can be tested, but the mock fails. Once this has been reversed, the mock test passes, but the squareRoot test fails again.
> test
[info] Compiling 1 Scala source to C:\path\to\developme
nt\scalaNumberSequences\target\scala-2.10\test-classes...
[error] C:\path\to\scalaNumberSequences\src
\test\scala\com\utrecht\numbersequences\NumberSequencesTest.scala:16: not found:
value NumberSequences
[error] assert(NumberSequences.squareRoot(25) === 5)
[error] ^
[error] one error found
[error] (test:compile) Compilation failed
[error] Total time: 1 s, completed Aug 10, 2014 11:47:13 AM
>

Answer 1

You have to instantiate a NumberSequences object, since it's a class, not an object or companion object.
assert(new NumberSequences().squareRoot(25) === 5)
To use this syntax:
assert(NumberSequences.squareRoot(25) === 5)
you would need this:
object NumberSequences {
def squareRoot(a: Double) : Double = {
math.sqrt(a)
}
}
But since you need to mock it (in the first test), I would rather use the first solution: instantiating the class.