Added BoundedByFinalType

input/src/main/scala/fix/BoundedByFinalType.scala

@@ -0,0 +1,25 @@
+/*
+rule = BoundedByFinalType
+ */
+package fix
+
+object BoundedByFinalType {
+  class Test[A <: String] // assert: BoundedByFinalType
+  def foo[B <: Integer](): Unit = {} // assert: BoundedByFinalType
+
+  val test: PartialFunction[Array[String], Int] = { // scalafix: ok;
+    case _ => -1
+  }
+  val a = List[String]("sam") // scalafix: ok;
+
+  class Test2[A <: Exception] // scalafix: ok;
+  class Test3[A <: Any] // scalafix: ok;
+  class Test4 // scalafix: ok;
+
+  def foo2[B <: Exception](): Unit = {} // scalafix: ok;
+  def foo3[B <: Any](): Unit = {} // scalafix: ok;
+  def foo4(): Unit = {} // scalafix: ok;
+
+  type Texty = String // scalafix: ok;
+  type ListBuffer[A] = scala.collection.mutable.ListBuffer[A] // scalafix: ok;
+}

rules/src/main/resources/META-INF/services/scalafix.v1.Rule

@@ -56,4 +56,5 @@ fix.AsInstanceOf
 fix.AvoidToMinusOne
 fix.BigDecimalDoubleConstructor
 fix.BigDecimalScaleWithoutRoundingMode
-fix.BooleanParameter
+fix.BooleanParameter
+fix.BoundedByFinalType

rules/src/main/scala/fix/BoundedByFinalType.scala

@@ -0,0 +1,32 @@
+/*
+rule = BoundedByFinalType
+ */
+package fix
+
+import scalafix.lint.LintSeverity
+import scalafix.v1._
+
+import scala.meta._
+
+class BoundedByFinalType extends SemanticRule("BoundedByFinalType") {
+
+  private def diag(pos: Position) = Diagnostic(
+    "",
+    "Checks for types with upper bounds of a final type.",
+    pos,
+    "Pointless type bound. Type parameter can only be a single value.",
+    LintSeverity.Warning
+  )
+
+  override def fix(implicit doc: SemanticDocument): Patch = {
+    doc.tree.collect {
+      // Corresponds to [A <: ...] in class Test[A <: String] or def foo[B <: Integer] = {}
+      case Type.ParamClause(List(params)) =>
+        params.collect {
+          // String is seen as Predef.String, not java/lang/String. String is final but not Predef.String, even though they are essentially the same.
+          case p @ Type.Param.After_4_6_0(_, _, _, Type.Bounds(_, hi), _, _) if hi.exists(h => h.symbol.info.exists(i => i.isFinal) || h.toString == "String") => Patch.lint(diag(p.pos))
+        }
+    }.flatten.asPatch
+  }
+
+}