wartremover.contrib.warts.UnintendedLaziness.scala Maven / Gradle / Ivy
package org.wartremover
package contrib.warts
object UnintendedLaziness extends WartTraverser {
val (errorForFilterKeys: String, errorForMapValues: String) = {
def error(name: String) =
s"""GenMapLike#$name is disabled because it implicitly creates lazily evaluated collections.
|To create lazy collections, use the explicit view or toStream methods""".stripMargin
(error("filterKeys"), error("mapValues"))
}
def apply(u: WartUniverse): u.Traverser = {
import u.universe._
val maybeGenMapLikeSymbol =
try {
Option(rootMirror.staticClass("scala.collection.GenMapLike"))
} catch {
case _: ScalaReflectionException =>
// If this happens, the type does not exist, in which case we're using 2.13+, where this wart is a no-op
None
}
maybeGenMapLikeSymbol
.map { genMapLikeSymbol =>
val filterKeys = TermName("filterKeys")
val mapValues = TermName("mapValues")
new u.Traverser {
override def traverse(tree: Tree): Unit = {
tree match {
// Ignore trees marked by SuppressWarnings
case t if hasWartAnnotation(u)(t) =>
case t @ Apply(Select(map, `filterKeys`), _) if map.tpe.baseType(genMapLikeSymbol) != NoType =>
error(u)(t.pos, errorForFilterKeys)
case t @ Apply(TypeApply(Select(map, `mapValues`), _), _) if map.tpe.baseType(genMapLikeSymbol) != NoType =>
error(u)(t.pos, errorForMapValues)
case _ =>
super.traverse(tree)
}
}
}
}
.getOrElse(new u.Traverser)
}
}