Cannot update or delete many in ReactiveMongo 0.16 - json

Question

I'm having some difficulty with delete.many and update.many using the new builders whilst trying to convert my previous version's (working) code into reactivemongo 0.16.5 ("org.reactivemongo" %% "play2-reactivemongo" % "0.16.5-play26", "org.reactivemongo" %% "reactivemongo-akkastream" % "0.16.5". As you'll see; I'm using this within the Play plugin so dealing with JSON (rather than BSON)
I'm going from the official documentation here. My errors are similar for both update & delete so I'll just post for update here to keep it trim.
Update command
def updateMany(collName: String)(quJsa: JsArray)(orderedBool: Boolean = false): Future[MultiBulkWriteResult] = {
lazy val updateBuilder = getCollection(collName).map(_.update(orderedBool))
quJsa.asOpt[Seq[JsObject]].map(
_.map(
x => x.as[MongoUpdateBuilder]
)
).map(
_.map(
x => updateBuilder.flatMap(
_.element(q = x.q, u = x.getSetUpdate, upsert = x.upsertBool, multi = x.multiBool)
)
)
).map(
x => Future.sequence(x)
).map(
_.flatMap(
x => updateBuilder.flatMap(
_.many(x)
)
)
).getOrElse(getMultiBulkWriteResultErrorF("input not recognised as jsarr"))
}
Custom update builder model
case class MongoUpdateBuilder(q: JsObject, u: JsObject, upsertBool: Boolean, multiBool: Boolean) {
def getSetUpdate = Json.obj("$set" -> u)
}
object MongoUpdateBuilder {
implicit val mongoUpdateBuilderFormat = Json.format[MongoUpdateBuilder]
}
Error container
def getMultiBulkWriteResultErrorF(errStr: String): Future[MultiBulkWriteResult] = {
val mbwr = MultiBulkWriteResult(
ok = false,
n = 0,
nModified = 0,
upserted = Seq(),
writeErrors = Seq(WriteError(index = 0, code = 404, errmsg = errStr)),
writeConcernError = None,
code = Some(404),
errmsg = Some(errStr),
totalN = 0
)
Future.successful(mbwr)
}
And the main issue:
no type parameters for method flatMap: (f: reactivemongo.play.json.collection
.JSONCollection#UpdateBuilder => scala.concurrent.Future[S])(implicit executor: scala.concurrent.ExecutionContext)scala.concurrent.Future[S] exist so that it can be applied to arguments (reactivemongo.play.json.collection.JSONCollection#UpdateBuilder => scala.concurrent.Future[_1.UpdateCommand.UpdateElement] forSome { val _1: reactivemongo.play.json.collection.J
SONCollection }) [error] --- because ---
[error] argument expression's type is not compatible with formal parameter type;
[error] found : reactivemongo.play.json.collection.JSONCollection#UpdateBuilder => scala.concurrent.Future[_1.UpdateCommand.UpdateElement] forSome { val _1: reactivemongo.play.jso
n.collection.JSONCollection }
[error] required: reactivemongo.play.json.collection.JSONCollection#UpdateBuilder => scala.concurrent.Future[?S]
[error] x => updateBuilder.flatMap(
So the issue seems to be this line - updateBuilder.flatMap. The Future cannot be flattened with these types (JSONCollection#UpdateBuilder & JSONCollection#UpdateCommand.UpdateElement). So I'm struggling with this one. Please reach out if you can see the issue here. Many thanks!