Respect keywords in access in code formatter

Author: josevalim

lib/elixir/lib/code/formatter.ex

@@ -393,10 +393,17 @@ defmodule Code.Formatter do
   end
 
   # foo[bar]
-  defp quoted_to_algebra({{:., _, [Access, :get]}, meta, [target | args]}, _context, state) do
+  defp quoted_to_algebra({{:., _, [Access, :get]}, meta, [target, arg]}, _context, state) do
     {target_doc, state} = remote_target_to_algebra(target, state)
-    {call_doc, state} = list_to_algebra(meta, args, state)
-    {concat(target_doc, call_doc), state}
+
+    {access_doc, state} =
+      if keyword?(arg) do
+        list_to_algebra(meta, arg, state)
+      else
+        list_to_algebra(meta, [arg], state)
+      end
+
+    {concat(target_doc, access_doc), state}
   end
 
   # %Foo{}

lib/elixir/src/elixir_parser.yrl

@@ -285,9 +285,9 @@ number -> char : handle_number(?exprs('$1'), '$1', number_value('$1')).
 parens_call -> dot_call_identifier call_args_parens : build_parens('$1', '$2', {[], []}).
 parens_call -> dot_call_identifier call_args_parens call_args_parens : build_nested_parens('$1', '$2', '$3', {[], []}).
 
-bracket_arg -> open_bracket kw close_bracket : build_list('$1', '$2', '$3').
-bracket_arg -> open_bracket container_expr close_bracket : build_list('$1', '$2', '$3').
-bracket_arg -> open_bracket container_expr ',' close_bracket : build_list('$1', '$2', '$4').
+bracket_arg -> open_bracket kw close_bracket : build_access_arg('$1', '$2', '$3').
+bracket_arg -> open_bracket container_expr close_bracket : build_access_arg('$1', '$2', '$3').
+bracket_arg -> open_bracket container_expr ',' close_bracket : build_access_arg('$1', '$2', '$4').
 
 bracket_expr -> dot_bracket_identifier bracket_arg : build_access(build_no_parens('$1', nil), '$2').
 bracket_expr -> access_expr bracket_arg : build_access('$1', '$2').
@@ -882,8 +882,10 @@ build_fn(Fn, Stab, End) ->
 
 %% Access
 
-build_access(Expr, {List, Location}) ->
-  Meta = meta_from_location(Location),
+build_access_arg(Left, Args, Right) ->
+  {Args, newlines_pair(Left, Right) ++ meta_from_token(Left)}.
+
+build_access(Expr, {List, Meta}) ->
   {{'.', Meta, ['Elixir.Access', get]}, Meta, [Expr, List]}.
 
 %% Interpolation aware

lib/elixir/test/elixir/code_formatter/calls_test.exs

@@ -1215,7 +1215,9 @@ defmodule Code.Formatter.CallsTest do
     end
 
     test "with keywords" do
-      assert_format "expr[foo: bar, baz: bat]", "expr[[foo: bar, baz: bat]]"
+      assert_format "expr[[]]", "expr[[]]"
+      assert_format "expr[foo: bar, baz: bat]", "expr[foo: bar, baz: bat]"
+      assert_format "expr[[foo: bar, baz: bat]]", "expr[[foo: bar, baz: bat]]"
     end
   end
 end

lib/elixir/test/elixir/code_formatter/comments_test.exs

@@ -358,6 +358,30 @@ defmodule Code.Formatter.CommentsTest do
     end
   end
 
+  describe "access" do
+    test "before and after single arg" do
+      assert_same ~S"""
+      foo[
+        # bar
+        baz
+        # bat
+      ]
+      """
+    end
+
+    test "before and after keywords" do
+      assert_same ~S"""
+      foo[
+        # bar
+        one: :two,
+        # baz
+        three: :four
+        # bat
+      ]
+      """
+    end
+  end
+
   describe "calls" do
     test "local with parens inside before and after" do
       assert_same ~S"""