Warn on deprecated ~~~ unary op in tokenizer (elixir-lang#14870)

Author: sabiwara

lib/elixir/src/elixir_tokenizer.erl

@@ -883,8 +883,18 @@ handle_unary_op(Rest, Line, Column, Kind, Length, Op, Scope, Tokens) ->
       Token = {identifier, {Line, Column, nil}, Op},
       tokenize(Remaining, NewLine, NewColumn, Scope, [Token | Tokens]);
     {Remaining, NewLine, NewColumn} ->
+      NewScope =
+        %% TODO: Remove these deprecations on Elixir v2.0
+        case Op of
+          '~~~' ->
+            Msg = "~~~ is deprecated. Use Bitwise.bnot/1 instead for clarity",
+            prepend_warning(Line, Column, Msg, Scope);
+          _ ->
+            Scope
+        end,
+
       Token = {Kind, {Line, Column, nil}, Op},
-      tokenize(Remaining, NewLine, NewColumn, Scope, [Token | Tokens])
+      tokenize(Remaining, NewLine, NewColumn, NewScope, [Token | Tokens])
   end.
 
 handle_op([$: | Rest], Line, Column, _Kind, Length, Op, Scope, Tokens) when ?is_space(hd(Rest)) ->
@@ -904,10 +914,6 @@ handle_op(Rest, Line, Column, Kind, Length, Op, Scope, Tokens) ->
             Msg = "^^^ is deprecated. It is typically used as xor but it has the wrong precedence, use Bitwise.bxor/2 instead",
             prepend_warning(Line, Column, Msg, Scope);
 
-          '~~~' ->
-            Msg = "~~~ is deprecated. Use Bitwise.bnot/1 instead for clarity",
-            prepend_warning(Line, Column, Msg, Scope);
-
           '<|>' ->
             Msg = "<|> is deprecated. Use another pipe-like operator",
             prepend_warning(Line, Column, Msg, Scope);

lib/elixir/test/erlang/tokenizer_test.erl

@@ -16,6 +16,10 @@ tokenize_error(String) ->
   {error, Error, _, _, _} = elixir_tokenizer:tokenize(String, 1, []),
   Error.
 
+tokenize_warnings(String) ->
+  {ok, _Line, _Column, Warnings, Result, []} = elixir_tokenizer:tokenize(String, 1, []),
+  {lists:reverse(Result), Warnings}.
+
 type_test() ->
   [{int, {1, 1, 1}, "1"},
    {type_op, {1, 3, nil}, '::'},
@@ -279,3 +283,13 @@ sigil_heredoc_test() ->
 invalid_sigil_delimiter_test() ->
   {[{line, 1}, {column, 1}], "invalid sigil delimiter: ", Message} = tokenize_error("~s\\"),
   true = lists:prefix("\"\\\" (column 3, code point U+005C)", lists:flatten(Message)).
+
+deprecated_operators_test() ->
+  {
+    [{xor_op, {1, 1, nil}, '^^^'}, {int, {1, 4, 1}, "1"}],
+    [{{1, 1}, "^^^ is deprecated. It is typically used as xor but it has the wrong precedence, use Bitwise.bxor/2 instead"}]
+  } = tokenize_warnings("^^^1"),
+  {
+    [{unary_op, {1, 1, nil}, '~~~'}, {int, {1, 4, 1}, "1"}],
+    [{{1, 1}, "~~~ is deprecated. Use Bitwise.bnot/1 instead for clarity"}]
+  } = tokenize_warnings("~~~1").