Added usability renames

scalafix/input/src/main/scala/fix/Usability.scala

@@ -0,0 +1,16 @@
+/*
+rule = v1
+ */
+package fix
+
+import cats.effect.IO
+import fs2._
+import scala.concurrent.ExecutionContext.Implicits.global
+
+trait Usability {
+  def s: Stream[IO, String]
+
+  val observe1 = s.observe1(_ => IO.unit)
+  val join = Stream.emit(s).join(1)
+  val joinUnbounded = Stream.emit(s).joinUnbounded
+}

scalafix/output/src/main/scala/fix/Usability.scala

@@ -0,0 +1,14 @@
+package fix
+
+import cats.effect.IO
+import fs2._
+import scala.concurrent.ExecutionContext.Implicits.global
+
+trait Usability {
+  def s: Stream[IO, String]
+
+  val observe1 = s.evalTap(_ => IO.unit)
+  val join = Stream.emit(s).parJoin(1)
+  val joinUnbounded = Stream.emit(s).parJoinUnbounded
+}
+

scalafix/rules/src/main/scala/fix/v1.scala

@@ -8,7 +8,7 @@ import fixUtils._
 class v1 extends SemanticRule("v1") {
   override def fix(implicit doc: SemanticDocument): Patch =
     (StreamAppRules(doc.tree) ++ SchedulerRules(doc.tree) ++ BracketRules(doc.tree) ++ ConcurrentDataTypesRules(
-      doc.tree) ++ ChunkRules(doc.tree)).asPatch
+      doc.tree) ++ ChunkRules(doc.tree) ++ UsabilityRenameRules(doc.tree)).asPatch
 }
 
 object fixUtils {
@@ -492,4 +492,21 @@ object ChunkRules {
   val pullOutputMatcher = SymbolMatcher.normalized("fs2/Pull#outputChunk.")
   val segmentMatcher = SymbolMatcher.normalized("fs2/Segment.")
 
+}
+
+object UsabilityRenameRules {
+  def apply(t: Tree)(implicit doc: SemanticDocument): List[Patch] =
+    t.collect {
+      case t @ observeMatcher(_: Term.Name) =>
+        Patch.replaceTree(t, "evalTap")
+      case t @ joinMatcher(_: Term.Name) =>
+        Patch.replaceTree(t, "parJoin")
+      case t @ joinUnboundedMatcher(_: Term.Name) =>
+        Patch.replaceTree(t, "parJoinUnbounded")
+    }
+
+  val observeMatcher = SymbolMatcher.normalized("fs2/Stream.InvariantOps#observe1.")
+  val joinMatcher = SymbolMatcher.normalized("fs2/Stream.PureOps#join.")
+  val joinUnboundedMatcher = SymbolMatcher.normalized("fs2/Stream.PureOps#joinUnbounded.")
+
 }