Allow configuration via TestOptions

[frgomes]

Background

SBT defines test frameworks like this:

object TestFrameworks {
  val ScalaCheck = TestFramework("org.scalacheck.ScalaCheckFramework")
  val ScalaTest =
    TestFramework("org.scalatest.tools.Framework", "org.scalatest.tools.ScalaTestFramework")
  val Specs = TestFramework("org.specs.runner.SpecsFramework")
  val Specs2 =
    TestFramework("org.specs2.runner.Specs2Framework", "org.specs2.runner.SpecsFramework")
  val JUnit = TestFramework("com.novocode.junit.JUnitFramework")
}

final class TestFramework(val implClassNames: String*) extends Serializable {
   ...
  }

ScalaTest recommends that command arguments can be passed to ScalaTest like this:

testOptions in Test += Tests.Argument(TestFrameworks.ScalaTest, "-oD")

More details: http://www.scalatest.org/user_guide/using_scalatest_with_sbt

Proposal

We could do something similar in sbt-doctest.

The application developer could do something like this below in his/her build.sbt:

// application developer picks one
val utestRunner = "doctest.runner.utest.Framework"
val scalaTestRunner = "doctest.runner.scalatest.Framework"
val specs2TestRunner = "doctest.runner.specs2.Framework"

val tf = new sbt.TestFramework(utestRunner)
...
testFrameworks ++= Seq(tf),
testOptions ++= Seq(Tests.Argument(tf, "--decodeHtmlEntities", "--markdownEnabled")),
...

By the way, the syntax shown above compiles.