I'm trying to use a Scala 2 enum with Quill, like so:

import io.getquill.MappedEncoding

object MyEnumType extends Enumeration {
  type MyEnumType = Value

  val ONE, TWO, THREE = Value

  implicit val encode: MappedEncoding[MyEnumType, String] =
    MappedEncoding(_.toString)
  implicit val decode: MappedEncoding[String, MyEnumType] =
    MappedEncoding(MyEnumType.withName)
}

But I'm ending up with an error from Postgres:

ERROR: operator does not exist: my_enum_type = character varying
  Hint: No operator matches the given name and argument types. You might need to add explicit type casts.

I'm printing out the query using translate, and the query is generated like so:

WHERE column_1 = ONE

Where I'm expecting it to be rendered like:

WHERE column_1 = 'ONE'

What's the proper way to handle enums with Quill in Scala 2.13?

I have been experimenting, including using the Enumeratum library, and enum values are still not being generated correctly.

Using the debugger, I can see that the custom encoder is being evaluated, but the result value never makes it to the generated query.

I have posted an example of the problem on Gist at Test.scala.