Specs2 wrap unit test in database transaction - specs2

Question

I'm updating my application from Specs2 2.3.12 to 3.6.1 and am having trouble updating the class which wraps our unit tests in a transaction.
The 2.3.12 class:
class DbTx extends AroundOutside[Session] {
var session: Option[Session] = None
def around[T : AsResult](t: => T) = {
Db.withTransaction { implicit s =>
session = Some(s)
val result = AsResult(t)
s.rollback()
result
}
}
def outside: Session = session.get
}
its usage:
"my unit test" in (new DbTx).apply { implicit session: Session =>
...
}
What I've tried in 3.6.1
class DbTx extends ForEach[Session] {
var session: Option[Session] = None
def foreach[T : AsResult](t: Session => T) = {
Db.withTransaction { implicit s =>
session = Some(s)
val result = AsResult(t)
s.rollback()
result
}
}
}
its usage:
"my unit test" in (new DbTx).foreach { implicit session: Session =>
...
}
but this seemed to produce an infinite loop between lines 6 & 4 of that block.
I also tried
class DbTx extends Around {
def around[T: AsResult](t: => T): Result = {
super.around {
Db.withTransaction { implicit s: Session =>
val result = AsResult(t)
s.rollback()
result
}
}
}
}
its usage:
"my unit test" in (new DbTx).around { implicit session: Session =>
...
}
but that results in
could not find implicit value for evidence parameter of type AsResult[Session => MatchResult[ ... ]]
I also tried
class DbTx extends Fixture[Session] {
def apply[T: AsResult](t: Session => T): Result = {
Db.withTransaction { implicit s: Session =>
val result = AsResult(t)
s.rollback()
result
}
}
}
its usage:
"my unit test" in (new DbTx) { implicit session: Session =>
...
}
which results in
could not find implicit value for evidence parameter of type AsResult[Session => T]
Edit
I'm also getting an infinite loop with this code:
import org.specs2.execute.AsResult
import org.specs2.mutable.Specification
import org.specs2.specification.ForEach
class DbTxSpec extends Specification with ForEach[Session] {
def foreach[T: AsResult](t: Session => T) = {
Db.withTransaction { implicit s => // infinite loop between here
try AsResult(t) // and here
finally s.rollback()
}
}
"my unit test" in { implicit session: Session =>
true must beTrue
}
}

Answer 1

If you want to pass in a Session you need to use have your specification extend the ForEach trait, not a special object. Something like:
class DbTxSpec extends Specification with ForEach[Session] {
var session: Option[Session] = None
def foreach[T : AsResult](t: Session => T) = {
Db.withTransaction { implicit s =>
session = Some(s)
try AsResult(t(session))
finally s.rollback()
}
}
"my unit test" in { implicit session: Session =>
...
}
}