PlayJsonReadsWrites.scala

package fix

import fix.PlayJsonReadsWrites.ImplicitValOrGiven

import scala.meta._
import scalafix.v1._

object PlayJsonReadsWrites {
  private object ImplicitValOrGiven {
    def unapply(t: Tree): Option[Type] = PartialFunction.condOpt(t) {
      case g: Defn.GivenAlias => g.decltpe
      case v @ Defn.Val(
          _,
          Pat.Var(_: Term.Name) :: Nil,
          Some(
           tpe
          ),
          _
      ) if v.mods.exists(_.is[Mod.Implicit]) => tpe
    }
  }
}

class PlayJsonReadsWrites extends SyntacticRule("PlayJsonReadsWrites") {
  override def fix(implicit doc: SyntacticDocument): Patch = {
    doc.tree.collect {
      case t: Stat =>
        val writes = t.collect{
          case ImplicitValOrGiven(
              Type.Apply.After_4_6_0(
                Type.Name("Writes"),
                Type.ArgClause(
                  List(
                    tpe
                  )
                )
              )
          ) =>
            tpe
        }
        val reads = t.collect{
          case ImplicitValOrGiven(
            Type.Apply.After_4_6_0(
              Type.Name("Reads"),
              Type.ArgClause(
                List(
                  tpe
                )
              )
            )
          ) =>
            tpe
        }
        writes.filter(w => reads.exists(_.structure == w.structure)).map{
          w =>
            Patch.lint(
              Diagnostic(
                id = "",
                message = "",
                position = w.pos
              )
            )
        }.asPatch
    }.asPatch
  }
}