Doobie and DB access composition within 1 transaction

Question

Doobie book says that it\'s a good practice to return ConnectionIO from your repository layer. It gives an ability to chain calls and perform them in one transaction. Nice

Answer 1

ConnectionIO in doobie has a cats.effect.Async instance, which, among other things, allows you do turn any cats.effect.IO into ConnectionIO by means of liftIO method:

import doobie.free.connection._
import cats.effect.{IO, Async}
val catsIO: IO[String] = ???
val cio: ConnectionIO[String] = Async[ConnectionIO].liftIO(catsIO)

For monix.eval.Task, your best bet is using Task#toIO and performing the same trick, but you'd need a monix Scheduler in scope.