org.wartremover.warts.ListUnapply.scala Maven / Gradle / Ivy
package org.wartremover
package warts
import scala.quoted.Type
object ListUnapply extends WartTraverser {
private[wartremover] def message: String = "Don't use `::` unapply method"
def apply(u: WartUniverse): u.Traverser = {
new u.Traverser(this) {
import q.reflect.*
val List(consUnapply) = TypeRepr.of[scala.collection.immutable.::.type].typeSymbol.methodMember("unapply")
def isListConsUnapply(t: Tree): Boolean = {
PartialFunction.cond(t) {
case t @ TypedOrTest(Unapply(f: TypeApply, _, _), _) =>
f.fun.symbol == consUnapply
case Bind(_, t @ TypedOrTest(Unapply(f: TypeApply, _, _), _)) =>
f.fun.symbol == consUnapply
}
}
override def traverseTree(tree: Tree)(owner: Symbol): Unit = {
tree match {
case t if hasWartAnnotation(t) =>
case m: Match =>
if (m.scrutinee.tpe.classSymbol == TypeRepr.of[List[?]].classSymbol) {
// this is a list
} else {
m.cases.map(_.pattern).withFilter(isListConsUnapply).foreach { x =>
error(x.pos, message)
}
}
case _ =>
super.traverseTree(tree)(owner)
}
}
}
}
}