fix.UnusedConstructorParams.scala Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of scalafix-rules_2.12 Show documentation
scalafix rules
There is a newer version: 0.6.7
package fix

import scala.meta.Defn
import scala.meta.Mod
import scala.meta.Stat
import scala.meta.XtensionClassifiable
import scala.meta.XtensionCollectionLikeUI
import scala.meta.inputs.Position
import scala.meta.termParamClauseToValues
import scalafix.Patch
import scalafix.lint.Diagnostic
import scalafix.lint.LintSeverity
import scalafix.v1.SyntacticDocument
import scalafix.v1.SyntacticRule
import scalafix.v1.XtensionSeqPatch

class UnusedConstructorParams extends SyntacticRule("UnusedConstructorParams") {
  override def isLinter = true

  override def fix(implicit doc: SyntacticDocument): Patch = {
    doc.tree.collect {
      case x: (Stat.WithTemplate & Stat.WithCtor & Stat.WithMods)
          if (x.is[Defn.Class] || x.is[Defn.Trait]) &&
            !x.mods.exists(_.is[Mod.Case]) =>
        val params = x.ctor.paramClauses.flatten
          .filterNot(_.mods.exists(_.is[Mod.Implicit]))
          .filterNot(_.mods.exists(_.is[Mod.Using]))
          .filterNot(_.mods.exists(_.is[Mod.VarParam]))
          .filterNot(_.mods.exists(_.is[Mod.ValParam]))
        val allTokens = {
          val values = x.templ.tokens.map(_.text).toSet
          values ++ values.filter(a => a.startsWith("`") && a.endsWith("`")).map(_.drop(1).dropRight(1))
        }
        val maybeUnused = params.filterNot(p => allTokens(p.name.value))
        maybeUnused.map { a =>
          Patch.lint(
            UnusedParamWarn(a.pos)
          )
        }.asPatch
      case x: Defn.Enum =>
        val params = x.ctor.paramClauses.flatten.filterNot(
          _.mods.exists(m => m.is[Mod.Implicit] || m.is[Mod.Using] || m.is[Mod.VarParam] || m.is[Mod.ValParam])
        )
        val allTokens = {
          val values =
            x.templ.body.stats
              .filterNot(s => s.is[Defn.EnumCase] || s.is[Defn.RepeatedEnumCase])
              .flatMap(_.tokens)
              .map(_.text)
              .toSet
          values ++ values.filter(a => a.startsWith("`") && a.endsWith("`")).map(_.drop(1).dropRight(1))
        }
        val maybeUnused = params.filterNot(p => allTokens(p.name.value))
        maybeUnused.map { a =>
          Patch.lint(
            UnusedParamWarn(a.pos)
          )
        }.asPatch
    }.asPatch
  }
}

case class UnusedParamWarn(override val position: Position) extends Diagnostic {
  override def message: String = s"maybe unused constructor param"

  override def severity: LintSeverity = LintSeverity.Warning
}