not_a_map.key should raise BadMapError for consistency

Author: josevalim

lib/elixir/lib/exception.ex

@@ -178,8 +178,7 @@ defmodule Exception do
   end
 
   @doc false
-  @spec _format_message_with_term(String.t(), any) :: String.t()
-  def _format_message_with_term(message, term) do
+  def __format_message_with_term__(message, term) do
     inspected =
       term
       |> inspect(pretty: true)
@@ -1447,7 +1446,7 @@ defmodule BadStructError do
 
   @impl true
   def message(exception) do
-    Exception._format_message_with_term(
+    Exception.__format_message_with_term__(
       "expected a struct named #{inspect(exception.struct)}, got:",
       exception.term
     )
@@ -1470,7 +1469,7 @@ defmodule BadMapError do
 
   @impl true
   def message(exception) do
-    Exception._format_message_with_term(
+    Exception.__format_message_with_term__(
       "expected a map, got:",
       exception.term
     )
@@ -1492,7 +1491,7 @@ defmodule BadBooleanError do
 
   @impl true
   def message(exception) do
-    Exception._format_message_with_term(
+    Exception.__format_message_with_term__(
       "expected a boolean on left-side of \"#{exception.operator}\", got:",
       exception.term
     )
@@ -1517,7 +1516,7 @@ defmodule MatchError do
 
   @impl true
   def message(exception) do
-    Exception._format_message_with_term(
+    Exception.__format_message_with_term__(
       "no match of right hand side value:",
       exception.term
     )
@@ -1546,7 +1545,7 @@ defmodule CaseClauseError do
 
   @impl true
   def message(exception) do
-    Exception._format_message_with_term(
+    Exception.__format_message_with_term__(
       "no case clause matching:",
       exception.term
     )
@@ -1579,7 +1578,7 @@ defmodule WithClauseError do
 
   @impl true
   def message(exception) do
-    Exception._format_message_with_term(
+    Exception.__format_message_with_term__(
       "no with clause matching:",
       exception.term
     )
@@ -1632,7 +1631,7 @@ defmodule TryClauseError do
 
   @impl true
   def message(exception) do
-    Exception._format_message_with_term(
+    Exception.__format_message_with_term__(
       "no try clause matching:",
       exception.term
     )
@@ -2197,7 +2196,7 @@ defmodule KeyError do
           "make sure to add parentheses after the function name)"
 
       true ->
-        Exception._format_message_with_term(
+        Exception.__format_message_with_term__(
           message <> " in:",
           term
         )

lib/elixir/src/elixir_erl_pass.erl

@@ -248,7 +248,6 @@ translate({{'.', _, [Left, Right]}, Meta, []}, _Ann, S)
 
   case proplists:get_value(no_parens, Meta, false) of
     true ->
-      TError = {tuple, Ann, [{atom, Ann, badkey}, TRight, TVar]},
       {{'case', Generated, TLeft, [
         {clause, Generated,
           [{map, Ann, [{map_field_exact, Ann, TRight, TVar}]}],
@@ -261,7 +260,7 @@ translate({{'.', _, [Left, Right]}, Meta, []}, _Ann, S)
             {clause, Generated,
              [{tuple, Generated, [{atom, Generated, ok}, TInnerVar]}], [], [TInnerVar]},
             {clause, Generated,
-             [{var, Generated, '_'}], [], [?remote(Ann, erlang, error, [TError])]}
+             [{tuple, Generated, [{atom, Generated, error}, TInnerVar]}], [], [?remote(Ann, erlang, error, [TInnerVar])]}
           ]}]}
       ]}, SV};
     false ->
@@ -716,9 +715,9 @@ generate_struct_name_guard([Field | Rest], Acc, S) ->
   generate_struct_name_guard(Rest, [Field | Acc], S).
 
 %% TODO: Make this a runtime error on Elixir v2.0
-no_parens_remote(nil, _Fun) -> error;
-no_parens_remote(false, _Fun) -> error;
-no_parens_remote(true, _Fun) -> error;
+no_parens_remote(nil, _Key) -> {error, {badmap, nil}};
+no_parens_remote(false, _Key) -> {error, {badmap, false}};
+no_parens_remote(true, _Key) -> {error, {badmap, false}};
 no_parens_remote(Atom, Fun) when is_atom(Atom) ->
   Message = fun() ->
     io_lib:format(
@@ -729,8 +728,10 @@ no_parens_remote(Atom, Fun) when is_atom(Atom) ->
   end,
   'Elixir.IO':warn_once(?MODULE, Message, 3),
   {ok, apply(Atom, Fun, [])};
-no_parens_remote(_Other, _Fun) ->
-  error.
+no_parens_remote(#{} = Map, Key) ->
+  {error, {badkey, Key, Map}};
+no_parens_remote(Other, _Key) ->
+  {error, {badmap, Other}}.
 
 parens_map_field(Key, Value) ->
   Message = fun() ->

lib/elixir/test/elixir/exception_test.exs

@@ -698,12 +698,6 @@ defmodule ExceptionTest do
                "function :erlang.hash/2 is undefined or private, use erlang:phash2/2 instead"
     end
 
-    test "annotates undefined key error with nil hints" do
-      assert blame_message(nil, & &1.foo) ==
-               "key :foo not found in: nil\n\nIf you are using the dot syntax, " <>
-                 "such as map.field, make sure the left-hand side of the dot is a map"
-    end
-
     test "annotates undefined function clause error with nil hints" do
       assert blame_message(nil, & &1.foo()) ==
                "function nil.foo/0 is undefined. If you are using the dot syntax, " <>