RedundantSyntax: distinguish single and triple quotes

scalafix-rules/src/main/scala/scalafix/internal/rule/RedundantSyntax.scala

@@ -30,15 +30,29 @@ class RedundantSyntax(config: RedundantSyntaxConfig)
               finalTok :: TokenList(o.tokens).trailingSpaces(finalTok).toList
             }
           }
-        case interpolator @ Term.Interpolate(
-              Term.Name(p),
-              Lit.String(v) :: Nil,
+        case Term.Interpolate(
+              interpolator,
+              lit :: Nil,
               Nil
             )
-            if config.stringInterpolator
-              && (p == "s" || p == "f" || (p == "raw" && !v.contains('\\'))) =>
-          Patch.removeTokens(interpolator.prefix.tokens)
+            if config.stringInterpolator &&
+              !mustKeepInterpolator(interpolator, lit) =>
+          Patch.removeTokens(interpolator.tokens)
       }
       .map(_.atomic)
       .asPatch
+
+  private def mustKeepInterpolator(interpolator: Tree, lit: Tree) = {
+    val escapedCharacter = lit.syntax.contains('\\')
+    // termInterpolate.syntax.contains("\"\"\"") does not work in scala 2.13 and scala 3
+    // as the syntax uses single quotes even if the litteral was defined with triple quotes
+    val tripleQuotes = lit.pos.start - interpolator.pos.end == 3
+    interpolator.syntax match {
+      case "s" | "f" =>
+        escapedCharacter && tripleQuotes
+      case "raw" =>
+        escapedCharacter && !tripleQuotes
+      case _ => true
+    }
+  }
 }

scalafix-tests/input/src/main/scala-2.12/test/redundantSyntax/StringInterpolator.scala

@@ -0,0 +1,44 @@
+/*
+rules = RedundantSyntax
+RedundantSyntax.stringInterpolator = true
+*/
+
+package test.redundantSyntax
+
+class StringInterpolator {
+
+  val a = 42d
+
+  var b = ""
+  b = "foo"
+  b = s"foo"
+  b = s"foo $a bar"
+  //b = s"my \"quoted\" string" does not compile as of 2.12.18 as https://github.com/scala/scala/pull/8830 was not backported
+
+  b = """foo"""
+  b =
+    s"""foo
+       |bar"""
+  b = s"""my \"quoted\" string"""
+  b = s"""foo $a bar"""
+  b = s"""$a"""
+
+  b = f"foo"
+  b = f"foo $a%2.2f"
+  b = f"foo \n bar"
+
+  b = raw"foo $a \nbar"
+  b = raw"""foo\nbar\\"""
+  b = raw"foo\nbar\\"
+  b = raw"foo bar"
+  b = raw"a\*b\+"
+
+  b = my"foo"
+  b = my"foo $a bar"
+
+  b = s"foo" // scalafix:ok
+
+  implicit class MyInterpolator(sc: StringContext) {
+    def my(subs: Any*): String = sc.toString + subs.mkString("")
+  }
+}

scalafix-tests/input/src/main/scala/test/redundantSyntax/StringInterpolator.scala → scalafix-tests/input/src/main/scala-2.13/test/redundantSyntax/StringInterpolator.scala

@@ -13,18 +13,22 @@ class StringInterpolator {
   b = "foo"
   b = s"foo"
   b = s"foo $a bar"
+  b = s"my \"quoted\" string"
 
   b = """foo"""
   b =
     s"""foo
        |bar"""
+  b = s"""my \"quoted\" string"""
   b = s"""foo $a bar"""
   b = s"""$a"""
 
   b = f"foo"
   b = f"foo $a%2.2f"
+  b = f"foo \n bar"
 
   b = raw"foo $a \nbar"
+  b = raw"""foo\nbar\\"""
   b = raw"foo\nbar\\"
   b = raw"foo bar"
   b = raw"a\*b\+"

scalafix-tests/input/src/main/scala-3/test/redundantSyntax/StringInterpolator.scala

@@ -0,0 +1,44 @@
+/*
+rules = RedundantSyntax
+RedundantSyntax.stringInterpolator = true
+*/
+
+package test.redundantSyntax
+
+class StringInterpolator {
+
+  val a = 42d
+
+  var b = ""
+  b = "foo"
+  b = s"foo"
+  b = s"foo $a bar"
+  b = s"my \"quoted\" string"
+
+  b = """foo"""
+  b =
+    s"""foo
+       |bar"""
+  b = s"""my \"quoted\" string"""
+  b = s"""foo $a bar"""
+  b = s"""$a"""
+
+  b = f"foo"
+  b = f"foo $a%2.2f"
+  b = f"foo \n bar"
+
+  b = raw"foo $a \nbar"
+  b = raw"""foo\nbar\\"""
+  b = raw"foo\nbar\\"
+  b = raw"foo bar"
+  b = raw"a\*b\+"
+
+  b = my"foo"
+  b = my"foo $a bar"
+
+  b = s"foo" // scalafix:ok
+
+  implicit class MyInterpolator(sc: StringContext) {
+    def my(subs: Any*): String = sc.toString + subs.mkString("")
+  }
+}

scalafix-tests/output/src/main/scala-2.12/test/redundantSyntax/StringInterpolator.scala

@@ -0,0 +1,39 @@
+package test.redundantSyntax
+
+class StringInterpolator {
+
+  val a = 42d
+
+  var b = ""
+  b = "foo"
+  b = "foo"
+  b = s"foo $a bar"
+  //b = s"my \"quoted\" string" does not compile as of 2.12.18 as https://github.com/scala/scala/pull/8830 was not backported
+
+  b = """foo"""
+  b =
+    """foo
+       |bar"""
+  b = s"""my \"quoted\" string"""
+  b = s"""foo $a bar"""
+  b = s"""$a"""
+
+  b = "foo"
+  b = f"foo $a%2.2f"
+  b = "foo \n bar"
+
+  b = raw"foo $a \nbar"
+  b = """foo\nbar\\"""
+  b = raw"foo\nbar\\"
+  b = "foo bar"
+  b = raw"a\*b\+"
+
+  b = my"foo"
+  b = my"foo $a bar"
+
+  b = s"foo" // scalafix:ok
+
+  implicit class MyInterpolator(sc: StringContext) {
+    def my(subs: Any*): String = sc.toString + subs.mkString("")
+  }
+}

scalafix-tests/output/src/main/scala/test/redundantSyntax/StringInterpolator.scala → scalafix-tests/output/src/main/scala-2.13/test/redundantSyntax/StringInterpolator.scala

@@ -8,18 +8,22 @@ class StringInterpolator {
   b = "foo"
   b = "foo"
   b = s"foo $a bar"
+  b = "my \"quoted\" string"
 
   b = """foo"""
   b =
     """foo
        |bar"""
+  b = s"""my \"quoted\" string"""
   b = s"""foo $a bar"""
   b = s"""$a"""
 
   b = "foo"
   b = f"foo $a%2.2f"
+  b = "foo \n bar"
 
   b = raw"foo $a \nbar"
+  b = """foo\nbar\\"""
   b = raw"foo\nbar\\"
   b = "foo bar"
   b = raw"a\*b\+"

scalafix-tests/output/src/main/scala-3/test/redundantSyntax/StringInterpolator.scala

@@ -0,0 +1,39 @@
+package test.redundantSyntax
+
+class StringInterpolator {
+
+  val a = 42d
+
+  var b = ""
+  b = "foo"
+  b = "foo"
+  b = s"foo $a bar"
+  b = "my \"quoted\" string"
+
+  b = """foo"""
+  b =
+    """foo
+       |bar"""
+  b = s"""my \"quoted\" string"""
+  b = s"""foo $a bar"""
+  b = s"""$a"""
+
+  b = "foo"
+  b = f"foo $a%2.2f"
+  b = "foo \n bar"
+
+  b = raw"foo $a \nbar"
+  b = """foo\nbar\\"""
+  b = raw"foo\nbar\\"
+  b = "foo bar"
+  b = raw"a\*b\+"
+
+  b = my"foo"
+  b = my"foo $a bar"
+
+  b = s"foo" // scalafix:ok
+
+  implicit class MyInterpolator(sc: StringContext) {
+    def my(subs: Any*): String = sc.toString + subs.mkString("")
+  }
+}