sbt doesn't recognize ScalaTest Table-driven property checks as tests - unit-testing

Question

I wrote some ScalaTest Table-driven property checks and I'm trying to run them with sbt test. Looking at the report I see that ScalaTest can recognize all the JUnit tests I have (they are in the same class as the checks), it runs property checks (i.e., forAll body), but it doesn't treat forAll as a test. If it fails I see the stack trace in the report (with ScalaTest failed test exception) and sbt says there was an "error" during the test run, but it says that all of the tests passed. The total number of tests in the report includes only JUnit tests.
Is there the support for this style of tests in sbt?

Answer 1

forAll in PropertyChecks is not a test. It is essentially a glorified assertion. You need to place assertions inside named tests. How to do that depends on your chosen style. For example, in FunSuite, you'd write something like:
class MySpec extends FunSuite with PropertyChecks {
test("give the test a name here") {
forAll(x: Int, y: Int) {
// make assertions here
}
}
}

Answer 2

Instead of calling forAll, make the test class extend from org.scalatest.prop.Checkers and then in each test, call check with the Property to be tested. In this case, "Property" probably means the forAll that you've created.
So I'm going to guess that currently you have a test class that looks like:
class ExampleSuite extends AssertionsForJUnit {
val fractions = Table(
("n", "d"),
( 1, 2),
///...
)
forAll (fractions) { (n: Int, d: Int) => // ...
#Test def verifySomethingElse = ???
}
I believe what you need to do is extend from Checkers and move your forAll into a test.
class ExampleSuite extends AssertionsForJUnit with org.scalatest.prop.Checkers {
#Test def verifyFractions = {
val fractions = Table(
("n", "d"),
( 1, 2),
///...
)
check(forAll (fractions) { (n: Int, d: Int) => ???)
}
#Test def verifySomethingElse = ???
}

Answer 3

The standard way is to create a FunSuite test with Matchers and TableDrivenPropertyCheck
Example:
import org.scalatest._
import org.scalatest.prop.TableDrivenPropertyChecks._
class CreateSpec extends FunSuite with Matchers {
test("B-Tree-Create for different degree parameter value") {
val params = Table(("degree", "result"),
(0, Tree(Leaf(), 0)),
(2, Tree(Leaf(), 1)),
(1999, Tree(Leaf(), 1999)))
forAll(params) {(degree, result) => Algorithms.create(degree) == result}
}
}