Test invalid string

src/jsonyx/_accelerator.c

@@ -475,7 +475,7 @@ scanstring_unicode(PyObject *pyfilename, PyObject *pystr, Py_ssize_t end, Py_ssi
  break;
  }
  if (next == len) {
- raise_errmsg("Invalid backslash escape", pyfilename, pystr, next);
+ raise_errmsg("Expecting escaped character", pyfilename, pystr, next);
  goto bail;
  }
  c = PyUnicode_READ(kind, buf, next);
@@ -491,6 +491,9 @@ scanstring_unicode(PyObject *pyfilename, PyObject *pystr, Py_ssize_t end, Py_ssi
  case 'n': c = '\n'; break;
  case 'r': c = '\r'; break;
  case 't': c = '\t'; break;
+ case '\n':
+ raise_errmsg("Expecting escaped character", pyfilename, pystr, end - 1);
+ goto bail;
  default: c = 0;
  }
  if (c == 0) {

src/jsonyx/_decoder.py

@@ -70,7 +70,8 @@ def _unescape_unicode(filename: str, s: str, pos: int) -> int:
  raise JSONSyntaxError(msg, filename, s, pos)
 
 
-def _scan_string(filename: str, s: str, end: int) -> ( # noqa: C901
+# pylint: disable-next=R0912
+def _scan_string(filename: str, s: str, end: int) -> ( # noqa: C901, PLR0912
  tuple[str, int]
 ):
  chunks: list[str] = []
@@ -105,14 +106,18 @@ def _scan_string(filename: str, s: str, end: int) -> ( # noqa: C901
  try:
  esc = s[end]
  except IndexError:
- msg = "Invalid backslash escape"
+ msg = "Expecting escaped character"
  raise JSONSyntaxError(msg, filename, s, end) from None
 
  # If not a unicode escape sequence, must be in the lookup table
  if esc != "u":
  try:
  char = _UNESCAPE[esc]
  except KeyError:
+ if esc == "\n":
+ msg = "Expecting escaped character"
+ raise JSONSyntaxError(msg, filename, s, end) from None
+
  msg = "Invalid backslash escape"
  raise JSONSyntaxError(msg, filename, s, end) from None
 

src/jsonyx/test_jsonyx/test_loads.py

@@ -173,6 +173,29 @@ def test_string(json: ModuleType, string: str, expected: Any) -> None:
  assert json.loads(string) == expected
 
 
+@pytest.mark.parametrize(("string", "msg", "colno"), [
+ ('"', "Unterminated string", 1),
+ ('"\n', "Unterminated string", 1),
+ ('"\b"', "Unescaped control character", 2),
+ ('"\\', "Expecting escaped character", 3),
+ ('"\\\n', "Expecting escaped character", 3),
+ (r'"\a"', "Invalid backslash escape", 3),
+ (r'"\u"', "Expecting 4 hex digits", 4),
+ (r'"\ud800\u"', "Expecting 4 hex digits", 10),
+])
+def test_invalid_string(
+ json: ModuleType, string: str, msg: str, colno: int,
+) -> None:
+ """Test invalid JSON string."""
+ with pytest.raises(json.JSONSyntaxError) as exc_info:
+ json.loads(string)
+
+ exc: Any = exc_info.value
+ assert exc.msg == msg
+ assert exc.lineno == 1
+ assert exc.colno == colno
+
+
 @pytest.mark.parametrize(("string", "expected"), [
  # Empty array
  ("[]", []),