From 40a830ab69855d052f16fc4457a5e5dc8892001e Mon Sep 17 00:00:00 2001
From: Matt Dziuban <mrdziuban@gmail.com>
Date: Mon, 7 Oct 2024 17:08:02 -0400
Subject: [PATCH] Fix bug that adds `using` incorrectly.

---
 .../main/scala-3/fix/GivenAndUsingTest.scala  |  5 ++++
 .../main/scala-3/fix/GivenAndUsingTest.scala  |  5 ++++
 rules/src/main/scala/fix/GivenAndUsing.scala  | 25 +++++++++--------
 .../fix/matchers/ImplicitOrUsingMod.scala     | 27 +++++++++++++++++++
 4 files changed, 49 insertions(+), 13 deletions(-)
 create mode 100644 rules/src/main/scala/fix/matchers/ImplicitOrUsingMod.scala

diff --git a/input/src/main/scala-3/fix/GivenAndUsingTest.scala b/input/src/main/scala-3/fix/GivenAndUsingTest.scala
index 925cbe7..8cef137 100644
--- a/input/src/main/scala-3/fix/GivenAndUsingTest.scala
+++ b/input/src/main/scala-3/fix/GivenAndUsingTest.scala
@@ -81,4 +81,9 @@ object WithExplicitUsing {
   def test(using i: Int): Int = i
   test(using 1)
 }
+object WithApplyAfterUsing {
+  given i: Int = 1
+  def test(using i: Int): String => String = s => s
+  test("")
+}
 // format: on
diff --git a/output/src/main/scala-3/fix/GivenAndUsingTest.scala b/output/src/main/scala-3/fix/GivenAndUsingTest.scala
index 23c12c5..ce7a886 100644
--- a/output/src/main/scala-3/fix/GivenAndUsingTest.scala
+++ b/output/src/main/scala-3/fix/GivenAndUsingTest.scala
@@ -65,4 +65,9 @@ object WithExplicitUsing {
   def test(using i: Int): Int = i
   test(using 1)
 }
+object WithApplyAfterUsing {
+  given i: Int = 1
+  def test(using i: Int): String => String = s => s
+  test("")
+}
 // format: on
diff --git a/rules/src/main/scala/fix/GivenAndUsing.scala b/rules/src/main/scala/fix/GivenAndUsing.scala
index 8265a68..90a7c53 100644
--- a/rules/src/main/scala/fix/GivenAndUsing.scala
+++ b/rules/src/main/scala/fix/GivenAndUsing.scala
@@ -16,7 +16,7 @@
 
 package fix
 
-import fix.matchers.ApplyImplicitArgs
+import fix.matchers.{ApplyImplicitArgs, ImplicitOrUsingMod}
 import scalafix.lint.LintSeverity
 import scalafix.v1._
 
@@ -59,25 +59,24 @@ class GivenAndUsing extends SemanticRule("GivenAndUsing") {
   }
 
   private def onlyImplicitOrUsingParams(d: Defn.Def): Boolean =
-    d.paramClauseGroups.forall(_.paramClauses.forall(_.mod.exists(m => m.is[Mod.Implicit] || m.is[Mod.Using])))
+    d.paramClauseGroups.forall(_.paramClauses.forall(_.mod.exists {
+      case ImplicitOrUsingMod(_) => true
+      case _                     => false
+    }))
 
   private def replaceWithUsing(paramss: List[List[Term.Param]])(implicit doc: SemanticDocument): List[APatch] = {
     val usingPatch = paramss.reverse.flatten
-      .collectFirst {
-        case p: Term.Param if p.mods.exists(mod => mod.is[Mod.Implicit] || mod.is[Mod.Using]) =>
-          val pp = p.mods
-            .find(_.is[Mod.Implicit])
-            .toList
-            .flatMap(_.tokens)
-            .headOption
+      .collectFirst { case p @ ImplicitOrUsingMod(mod) =>
+        if (mod.is[Mod.Using])
+          APatch.Empty
+        else {
+          val pp = mod.tokens.headOption
             .map(t => Patch.replaceToken(t, "using"))
             .asPatch
           APatch.Using(pp, p.symbol.owner)
+        }
       }
-    val lintPatchers = paramss.flatMap(_.collectFirst {
-      case p: Term.Param if p.mods.exists(mod => mod.is[Mod.Implicit] || mod.is[Mod.Using]) =>
-        p.mods.find(mod => mod.is[Mod.Implicit] || mod.is[Mod.Using])
-    }.toList.flatten) match {
+    val lintPatchers = paramss.flatMap(_.collectFirst { case ImplicitOrUsingMod(mod) => mod }.toList) match {
       case Nil      => List.empty
       case _ :: Nil => List.empty
       case other =>
diff --git a/rules/src/main/scala/fix/matchers/ImplicitOrUsingMod.scala b/rules/src/main/scala/fix/matchers/ImplicitOrUsingMod.scala
new file mode 100644
index 0000000..9b8c4a0
--- /dev/null
+++ b/rules/src/main/scala/fix/matchers/ImplicitOrUsingMod.scala
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2022 Arktekk
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package fix.matchers
+
+import scala.meta._
+
+object ImplicitOrUsingMod {
+  def unapply(mod: Mod): Option[Mod] =
+    if (mod.is[Mod.Implicit] || mod.is[Mod.Using]) Some(mod) else None
+
+  def unapply(param: Term.Param): Option[Mod] =
+    param.mods.collectFirst { case ImplicitOrUsingMod(mod) => mod }
+}