Trait BeforeAndAfterEach defines two overloaded variants each of beforeAll and afterAll, one which takes a configMap and another that takes no arguments. This traits implemention of the variant that takes the configMap simply invokes the variant that takes no parameters, which does nothing. Thus you can override whichever variant you want. If you need something from the configMap before all tests and nested suites are run, override beforeAll(Map[String, Any]). Otherwise, override beforeAll().

For example, the following MasterSuite mixes in BeforeAndAfterAll and in beforeAll, creates and writes to a temp file, taking the name of the temp file from the configMap. This same configMap is then passed to the run methods of the nested suites, OneSuite, TwoSuite, RedSuite, and BlueSuite, so those suites can access the filename and, therefore, the file's contents. After all of the nested suites have executed, afterAll is invoked, which again grabs the file name from the configMap and deletes the file:

 import org.scalatest.SuperSuite
 import org.scalatest.BeforeAndAfterEach
 import java.io.FileReader
 import java.io.FileWriter
 import java.io.File

 class MasterSuite extends Suite with BeforeAndAfterAll {

   private val FileNameKeyInGoodies = "tempFileName"

   // Set up the temp file needed by the test, taking
   // a file name from the configMap
   override def beforeAll(configMap: Map[String, Any]) {

     require(
       configMap.isDefinedAt(FileNameKeyInGoodies),
       "must place a temp file name in the configMap under the key: " + FileNameKeyInGoodies
     )

     val fileName = configMap(tempFileName))

     val writer = new FileWriter(fileName)
     try {
       writer.write("Hello, suite of tests!")
     }
     finally {
       writer.close()
     }
   }

   override def nestedSuites =
     List(new OneSuite, new TwoSuite, new RedSuite, new BlueSuite)
 
   // Delete the temp file
   override def afterAll(configMap: Map[String, Any]) {
     // No need to require that configMap contains the key again because it won't get
     // here if it didn't contain the key in beforeAll 
     val fileName = configMap(tempFileName))
     val file = new File(fileName)
     file.delete()
   }
 }
 

Because the BeforeAndAfterAll trait invokes super.run to run the suite, you may need to mix this trait in last to get the desired behavior. For example, this won't work, because BeforeAndAfterAll is "super" to FunSuite:

 class MySuite extends BeforeAndAfterAll with FunSuite
 

You'd need to turn it around, so that FunSuite is "super" to BeforeAndAfterAll, like this:

 class MySuite extends FunSuite with BeforeAndAfterAll