Fix ParserError#json_path with symbolize_names: true

CHANGES.md

@@ -2,6 +2,8 @@
 
 ### Unreleased
 
+* Fix `JSON::ParserError#json_path` raising `NoMethodError` when the document was parsed with `symbolize_names: true`.
+
 ### 2026-10-13 (3.1.0)
 
 * Added `rfc8785` generator option to canonicalize the output. Replaces the `json-canonicalization` with numerous correctness fixes.

lib/json/common.rb

@@ -171,13 +171,14 @@ def build_json_path(segments)
         when Integer
           "[#{segment}]"
         when String, Symbol
+          segment = segment.to_s
           if !segment.valid_encoding?
             segment = segment.b.gsub(/["\\]/n, { '"' => '\\"', '\\' => '\\\\' }).force_encoding(Encoding::UTF_8)
             %{["#{segment}"]}
           elsif segment.match?(/\A[a-zA-Z\$\_][a-zA-Z\$\_0-9]*\z/)
             ".#{segment}"
           else
-            segment = segment.to_s.gsub(/["\\]/, { '"' => '\\"', '\\' => '\\\\' })
+            segment = segment.gsub(/["\\]/, { '"' => '\\"', '\\' => '\\\\' })
             %{["#{segment}"]}
           end
         else

test/json/json_parser_test.rb

@@ -1004,6 +1004,18 @@ def test_parse_error_json_path_key_escaping
     assert_parse_error_at '$.foo["1x"]', '{"foo": {"1x": xyz}}'
   end
 
+  def test_parse_error_json_path_symbolize_names
+    assert_parse_error_at "$.a[1].b" do
+      JSON.parse('{"a": [1, {"b": xyz}]}', symbolize_names: true)
+    end
+    assert_parse_error_at '$["hello world"]' do
+      JSON.parse('{"hello world": xyz}', symbolize_names: true)
+    end
+    assert_parse_error_at "$.x.a" do
+      JSON.parse('{"x": {"a": 1, "a": 2}}', symbolize_names: true)
+    end
+  end
+
   def test_parse_error_json_path_duplicate_key
     assert_parse_error_at "$.a", '{"a": 1, "a": 2}'
     assert_parse_error_at "$.x.a", '{"x": {"a": 1, "b": 2, "a": 3}}'