Allow flow control operators to skip parens when they have single args

Author: DRBragg

lib/syntax_tree/node.rb

@@ -2066,7 +2066,12 @@ def format(q)
             part = arguments.parts.first
 
             if part.is_a?(Paren)
-              q.format(arguments)
+              if part.contents.body.length == 1 && skip_parens?(part.contents.body.first)
+                q.text(" ")
+                q.format(part.contents.body.first)
+              else
+                q.format(arguments)
+              end
             elsif part.is_a?(ArrayLiteral)
               q.text(" ")
               q.format(arguments)
@@ -2091,6 +2096,17 @@ def format_arguments(q, opening, closing)
       q.breakable("")
       q.if_break { q.text(closing) }
     end
+
+    def skip_parens?(node)
+      case node
+      in Int | FloatLiteral
+        true
+      in VarRef[value: GVar | IVar | CVar | Kw | Const]
+        true
+      else
+        false
+      end
+    end
   end
 
   # Break represents using the +break+ keyword.

test/fixtures/next.rb

@@ -25,3 +25,31 @@
   foo
   bar
 )
+%
+next(1)
+-
+next 1
+%
+next(1.0)
+-
+next 1.0
+%
+next($a)
+-
+next $a
+%
+next(@@a)
+-
+next @@a
+%
+next(self)
+-
+next self
+%
+next(@a)
+-
+next @a
+%
+next(A)
+-
+next A