RedundantBraces: fix how we find {} in func body

Fixes scalameta#1583.
kitbellew · Dec 5, 2019 · 575cc76 · 575cc76
1 parent a2d2449
commit 575cc76
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Showing 2 changed files with 31 additions and 11 deletions.
diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/rewrite/RedundantBraces.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/rewrite/RedundantBraces.scala
@@ -104,11 +104,15 @@ case object RedundantBraces extends Rewrite {
         if f.tokens.last.is[Token.RightBrace] && getTermLineSpan(f) > 0 =>
       val rbrace = f.tokens.last
       val lbrace = ctx.matchingParens(TokenOps.hash(rbrace))
-      val lparen = ctx.matchingParens(TokenOps.hash(rparen))
-      builder += TokenPatch.Replace(lparen, lbrace.text)
-      builder += TokenPatch.Remove(lbrace)
-      builder += TokenPatch.Remove(rparen)
-      removeTrailingLF(rbrace.pos, rparen)
+      // we really wanted the first token of body but Block usually
+      // points to the next non-whitespace token after opening brace
+      if (lbrace.start <= f.body.tokens.head.start) {
+        val lparen = ctx.matchingParens(TokenOps.hash(rparen))
+        builder += TokenPatch.Replace(lparen, lbrace.text)
+        builder += TokenPatch.Remove(lbrace)
+        builder += TokenPatch.Remove(rparen)
+        removeTrailingLF(rbrace.pos, rparen)
+      }
     case _ =>
   }
 
@@ -124,12 +128,14 @@ case object RedundantBraces extends Rewrite {
           && exactlyOneStatement(body) && isLineSpanOk(body) =>
       val rbrace = fun.tokens.last
       val lbrace = ctx.matchingParens(TokenOps.hash(rbrace))
-      builder += TokenPatch.Remove(lbrace)
-      builder += TokenPatch.Remove(rbrace)
-      removeTrailingLF(lbrace.pos, rbrace)
-      ctx.tokenTraverser
-        .reverseFind(rbrace)(!Whitespace.unapply(_))
-        .foreach(t => removeTrailingLF(t.pos, rbrace))
+      if (lbrace.start <= body.tokens.head.start) {
+        builder += TokenPatch.Remove(lbrace)
+        builder += TokenPatch.Remove(rbrace)
+        removeTrailingLF(lbrace.pos, rbrace)
+        ctx.tokenTraverser
+          .reverseFind(rbrace)(!Whitespace.unapply(_))
+          .foreach(t => removeTrailingLF(t.pos, rbrace))
+      }
     case _ =>
   }
 

diff --git a/scalafmt-tests/src/test/resources/rewrite/RedundantBraces-case.stat b/scalafmt-tests/src/test/resources/rewrite/RedundantBraces-case.stat
@@ -75,3 +75,17 @@ object a {
   }
 
 }
+<<< #1583 1 shouldn't remove "redundant braces"
+val a = b.c(d =>
+ e match {  case f =>
+})
+>>>
+val a = b.c(d =>
+  e match {
+    case f =>
+  }
+)
+<<< #1583 2 shouldn't remove "redundant braces"
+val a = b.c(d => {e}, f =>g match {  case h =>})
+>>>
+val a = b.c(d => e, f => g match { case h => })