Types with only optional values may be wrong in Elm

[nikitaDanilenko]

A Scala type satisfying the properties:

1. All fields are optional
2. The generated Elm file is in its own file

yields an incorrect Elm file, because an import is missing.

Reconstruction

import bridges.core.syntax._
import bridges.elm.Elm

object Issue {

  case class OptionOnly(
      number: Option[Int]
  )

  def main(args: Array[String]): Unit = {
    val (_, content) = Elm.buildFile(
      module = "TestModule",
      decls = List(
        decl[OptionOnly]
      ),
      customTypeReplacements = Map.empty
    )
    println(content)
  }

}

The distinction, whether or not the decoders contain required needs to be removed in ElmFileBuilder.scala.