Respect :no_parens meta in nullary remote calls in Macro.to_string

Closes #9668.

Author: José Valim

lib/elixir/lib/macro.ex

@@ -894,6 +894,16 @@ defmodule Macro do
   end
 
   # All other calls
+  def to_string({target, meta, []} = ast, fun) do
+    target = call_to_string(target, fun)
+
+    if meta[:no_parens] do
+      fun.(ast, target)
+    else
+      fun.(ast, target <> "()")
+    end
+  end
+
   def to_string({target, _, args} = ast, fun) when is_list(args) do
     with :error <- unary_call(ast, fun),
          :error <- binary_call(ast, fun),

lib/elixir/src/elixir_quote.erl

@@ -282,10 +282,11 @@ do_quote(Other, _, _) ->
 
 %% do_escape
 
-do_escape({Left, _Meta, Right}, Q, E = prune_metadata) ->
+do_escape({Left, Meta, Right}, Q, E = prune_metadata) ->
+  TM = [{K, V} || {K, V} <- Meta, (K == no_parens) orelse (K == line)],
   TL = do_quote(Left, Q, E),
   TR = do_quote(Right, Q, E),
-  {'{}', [], [TL, [], TR]};
+  {'{}', [], [TL, TM, TR]};
 
 do_escape(Tuple, Q, E) when is_tuple(Tuple) ->
   TT = do_quote(tuple_to_list(Tuple), Q, E),

lib/elixir/test/elixir/macro_test.exs

@@ -288,19 +288,24 @@ defmodule MacroTest do
       assert Macro.to_string(quoted) == "(foo do\n  :ok\nend).bar([1, 2, 3])"
     end
 
+    test "nullary remote call" do
+      assert Macro.to_string(quote do: foo.bar) == "foo.bar"
+      assert Macro.to_string(quote do: foo.bar()) == "foo.bar()"
+    end
+
     test "atom remote call" do
       assert Macro.to_string(quote(do: :foo.bar(1, 2, 3))) == ":foo.bar(1, 2, 3)"
     end
 
     test "remote and fun call" do
-      assert Macro.to_string(quote(do: foo.bar.(1, 2, 3))) == "foo.bar().(1, 2, 3)"
-      assert Macro.to_string(quote(do: foo.bar.([1, 2, 3]))) == "foo.bar().([1, 2, 3])"
+      assert Macro.to_string(quote(do: foo.bar().(1, 2, 3))) == "foo.bar().(1, 2, 3)"
+      assert Macro.to_string(quote(do: foo.bar().([1, 2, 3]))) == "foo.bar().([1, 2, 3])"
     end
 
     test "unusual remote atom fun call" do
       assert Macro.to_string(quote(do: Foo."42"())) == ~s/Foo."42"()/
       assert Macro.to_string(quote(do: Foo."Bar"())) == ~s/Foo."Bar"()/
-      assert Macro.to_string(quote(do: Foo."bar baz"()."")) == ~s/Foo."bar baz"().""()/
+      assert Macro.to_string(quote(do: Foo."bar baz"().""())) == ~s/Foo."bar baz"().""()/
       assert Macro.to_string(quote(do: Foo."%{}"())) == ~s/Foo."%{}"()/
       assert Macro.to_string(quote(do: Foo."..."())) == ~s/Foo."..."()/
     end