Scala - ScalaTest: simulate input while testing - scala

Question

I've a application that's run on top of terminal.
This App uses only Scala and SBT and I'm testing it using ScalaTest.
I want to test all components like a integration test, running the app, but, for that, I want to simulate the user sending values via standard input using something like a robot. Most important of all, when I call readLine or readInt, I want to send differents values while testing.
Thanks in advance!
Edit 1
So, I've this code. It basically prints the options for the user. I want, for example, to send 1, and then 3,4, to create a new Cell and check my CellArray to check if a new cell was really created in that position.
do {
println("Select one of the options: \n \n");
println("[1] Make a cell alive");
println("[2] Next generation");
println("[3] Halt");
print("\n \n Option: ");
option = parseOption(readLine)
}while(option == 0)
option match {
case MAKE_CELL_ALIVE => makeCellAlive
case NEXT_GENERATION => nextGeneration
case HALT => halt
}

Answer 1

The general approach will be something along these lines.
// This is the class containing the logic you want to test
class MyInputThing {
def readInput() = readLine
def thingIWantToTest = {
val input = readInput
doStuffWithInput(input)
}
}
// This test class returns a value representing something you want to verify.
class TestMyInputThing extends MyInputThing {
override def readInput = "123"
}
Then, in your test, use TestMyInputThing.thingIWantToTest() and validate the response. You can also pull out readInput into a trait, parameterise the creation of TestMyInputThing, etc, in order to clean this up. I would also recommend looking into ScalaCheck so you don't need to handcode test scenarios.