flyway scala migration

SlickMigration.scala

import java.sql.Connection

import org.flywaydb.core.api.migration.jdbc.JdbcMigration
import slick.dbio.DBIO

import scala.concurrent.duration.Duration
import scala.concurrent.{Await, ExecutionContext}

abstract class SlickMigration extends JdbcMigration {
  implicit def executionContext = ExecutionContext.global

  def action: DBIO[Any]

  final override def migrate(connection: Connection): Unit = {
    val db = new UnmanagedDatabase(connection)
    val future = db.run(action)
    future.onFailure {
      case e => e.printStackTrace()
    }
    Await.result(future, Duration.Inf)
  }
}

UnmanagedDatabase.scala

import java.sql.Connection

import slick.jdbc.JdbcBackend.{BaseSession, DatabaseDef}
import slick.jdbc.{JdbcBackend, JdbcDataSource}
import slick.util.AsyncExecutor

class UnmanagedJdbcDataSource(conn: Connection) extends JdbcDataSource {
  def createConnection() = conn
  def close() = ()
}

class UnmanagedSession(database: DatabaseDef) extends BaseSession(database) {
  override def close() = ()
}

class UnmanagedDatabase(conn: Connection) extends JdbcBackend.DatabaseDef(new  UnmanagedJdbcDataSource(conn), AsyncExecutor("UmanagedDatabase-AsyncExecutor", 1, -1)) {
  override def createSession() = new UnmanagedSession(this)
}

V6__housing_unit_development_id.scala

import java.sql.Types
import java.util.UUID

import slick.driver.H2Driver._
import api._
import slick.jdbc.{GetResult, SetParameter}

class V6__housing_unit_development_id extends SlickMigration {
  implicit val setParam = SetParameter[UUID]((uuid, pp) => pp.setObject(uuid, Types.VARCHAR))
  implicit val getResult = GetResult[UUID](_.nextObject().asInstanceOf[UUID])

  def action = {
    val myUuid = UUID.randomUUID()
    sql"SELECT count(*) FROM housing_unit".as[Int].head flatMap {
      case 0 =>
        sqlu"ALTER TABLE housing_unit ADD development_id UUID NOT NULL"
      case _ =>
        DBIO.seq(
          sqlu"INSERT INTO development (id, name) VALUES ($myUuid, 'default development')",
          sqlu"ALTER TABLE housing_unit ADD development_id UUID",
          sqlu"UPDATE housing_unit SET development_id = $myUuid",
          sqlu"ALTER TABLE housing_unit ALTER COLUMN development_id SET NOT NULL"
        )
    } andThen
      sqlu"ALTER TABLE housing_unit ADD FOREIGN KEY (development_id) REFERENCES development(id) ON DELETE RESTRICT ON UPDATE CASCADE"
  }
}