Fix wartremover#288 StringPlusAny

tim-zh · Dec 17, 2016 · 88c06cc · 88c06cc
1 parent 8c7a70e
commit 88c06cc
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Showing 2 changed files with 19 additions and 24 deletions.
diff --git a/core/src/main/scala/wartremover/warts/StringPlusAny.scala b/core/src/main/scala/wartremover/warts/StringPlusAny.scala
@@ -6,38 +6,26 @@ object StringPlusAny extends WartTraverser {
     import u.universe._
 
     val Plus: TermName = "$plus"
-    val PredefName: TermName = "Predef"
-    val Any2StringAddName: TermName = "any2stringadd"
+
+    def isString(t: Tree) = t.tpe <:< typeOf[String]
+
+    def isStringExpression(t: Tree) = t match {
+      //workaround: type of some expressions is inferred to Any during wart search since Scala 2.11
+      //this check doesn't cover all possible cases
+      case If(_, thn, els) => isString(thn) && isString(els)
+      case _ => isString(t)
+    }
 
     new u.Traverser {
       override def traverse(tree: Tree): Unit = {
         tree match {
           // Ignore trees marked by SuppressWarnings
           case t if hasWartAnnotation(u)(t) =>
 
-          case Apply(Select(Apply(Select(Select(_, PredefName), Any2StringAddName), _), Plus), _) =>
+          case t @ Apply(Select(lhs, Plus), List(rhs)) if isString(t) && (isString(lhs) ^ isStringExpression(rhs))
+              && !isSynthetic(u)(t) =>
             u.error(tree.pos, "Implicit conversion to string is disabled")
             super.traverse(tree)
-          case Apply(Select(TypeApply(Select(Select(_, PredefName), Any2StringAddName), _), Plus), _) =>
-            u.error(tree.pos, "Implicit conversion to string is disabled")
-            super.traverse(tree)
-
-          case Apply(Select(lhs, Plus), List(rhs))
-            if (lhs.tpe <:< typeOf[String] ^ rhs.tpe <:< typeOf[String]) && !isSynthetic(u)(tree) =>
-            val validIf = rhs match {
-              case If(_, then, els) => then.tpe <:< typeOf[String] && els.tpe <:< typeOf[String]
-              case _ => false
-            }
-            val overriddenPlus = lhs.symbol != null && lhs.symbol.owner != null && {
-              val owner = lhs.symbol.owner
-              owner.isClass && !owner.isSynthetic && owner.typeSignature.members.exists { x =>
-                x.isMethod && x.name.toTermName == Plus && !x.annotations.exists(isWartAnnotation(u))
-              }
-            }
-            if (!(overriddenPlus || validIf)) {
-              u.error(tree.pos, "Implicit conversion to string is disabled")
-            }
-            super.traverse(tree)
 
           case _ => super.traverse(tree)
         }

diff --git a/core/src/test/scala/wartremover/warts/StringPlusAnyTest.scala b/core/src/test/scala/wartremover/warts/StringPlusAnyTest.scala
@@ -38,9 +38,16 @@ class StringPlusAnyTest extends FunSuite with ResultAssertions {
     assertEmpty(result)
   }
 
+  test("inserting into a Set is allowed") {
+    val result = WartTestTraverser(StringPlusAny) {
+      Set("") + ""
+    }
+    assertEmpty(result)
+  }
+
   test("custom-defined + is allowed") {
     val result = WartTestTraverser(StringPlusAny) {
-      class C { def +(s: String) = s }
+      class C { def +(s: String) = this }
       new C + "a"
     }
     assertEmpty(result)