initializate value only once before all tests runs

Question

I want to initializate value only once before all tests runs

Now the value insertDbScheme create scheme in every test, if it possible to run it only once. Insert scheme from sbt task not suitable

I have two tests

test1:

class Test1 extends Specification with InsertDbScheme {

  "test" in {
    insertDbScheme
    // some code
    ok
  }
}

test2:

class Test2 extends Specification with InsertDbScheme {

  "test" in {
    insertDbScheme
    // some code
    ok
  }
}

and a base trait that insert scheme to database

trait InsertDbScheme {

  lazy val insertDbScheme = {
    println("insert scheme to database")
  }
}

result of running tests

insert scheme to database
insert scheme to database
[info] Test1
[info] 
[info] + test
[info] 
[info] 
[info] Total for specification Test1
[info] Finished in 152 ms
[info] 1 example, 0 failure, 0 error
[info] 
[info] Test2
[info] 
[info] + test
[info] 
[info] 
[info] Total for specification Test2
[info] Finished in 152 ms
[info] 1 example, 0 failure, 0 error
[info] 
[info] ScalaCheck
[info] Passed: Total 0, Failed 0, Errors 0, Passed 0
[info] Passed: Total 2, Failed 0, Errors 0, Passed 2
[success] Total time: 12 s, completed May 18, 2017 6:35:21 PM

Answer 1

You can use an object to make sure it's lazy val is only instantiated once:

trait InsertDbScheme {
  import InsertDbScheme._
  lazy val insertDbScheme = insertDbSchemeOnce
}

object InsertDbScheme { 
  lazy val insertDbSchemeOnce = {
    println("insert scheme to database")
  }
}