When I run tests with scalaTestPlus and Play framework, I get an error "no started application" - scala

Question

I'm trying to make scalaTestPlus work in my play application (I'm using Play! 2.2). It works well until I need a function coming from my application. For instance, if I run this very simple test (by launching in a sbt console "test-only TestName"):
import org.scalatestplus.play._
import org.scalatest._
import Matchers._
class Test extends PlaySpec {
"This test" must {
"run this very simple test without problem" in {
1 mustEqual 1
}
}
}
There is no problem, but as soon as I call a function from my app, like in this code:
class Test extends PlaySpec {
"This test" must {
"run this very simple test without problem" in {
models.Genre.genresStringToGenresSet(Option("test")) //Here is the problem
1 mustEqual 1
}
}
}
I get an error: java.lang.ExceptionInInitializerError: at... Cause: java.lang.RuntimeException: There is no started application (even if my application is running).
I'm probably missing something simple since I'm brand new to ScalaTest, so any help abut what I'm doing wrong would be apreciated ;)

Answer 1

You may need an application in scope when using PlaySpec, as some operations assume that there is a Play application available via Play.current:
class Test extends PlaySpec {
implicit override lazy val app: FakeApplication = FakeApplication(...)
"This test" must {
"run this very simple test without problem" in {
models.Genre.genresStringToGenresSet(Option("test")) //Here is the problem
1 mustEqual 1
}
}
}
Check the functional testing documentation for more details on FakeApplication.
However, I don't think you need should need this for model testing. In the normal ScalaTest docs for play, it seems to just mix inMockitoSugar. But your method call chain may invoke some global state of Play that does require an Application, in which case the FakeApplication is the way to go

Answer 2

As asked by #akauppi, here is a method that works perfectly for me:
import org.scalatestplus.play.{OneAppPerSuite, PlaySpec}
class A extends PlaySpec with OneAppPerSuite {
"a" must {
"return true" in {
//thanks to with OneAppPerSuite, it now works
models.Genre.genresStringToGenresSet(Option("test"))
1 mustBe 1
}
"return false" in {
1 mustBe 2
}
}
}
And I simply launch the test with sbt ~testOnly a