gh-126175: Add attributes to TOMLDecodeError. Deprecate free-form `__init__` args (GH-126428)

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Taneli Hukkinen 2024-11-13 14:52:16 +02:00 committed by GitHub
parent a12690ef49
commit 29b5323c45
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4 changed files with 163 additions and 52 deletions

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@ -60,9 +60,36 @@ This module defines the following functions:
The following exceptions are available:
.. exception:: TOMLDecodeError
.. exception:: TOMLDecodeError(msg, doc, pos)
Subclass of :exc:`ValueError`.
Subclass of :exc:`ValueError` with the following additional attributes:
.. attribute:: msg
The unformatted error message.
.. attribute:: doc
The TOML document being parsed.
.. attribute:: pos
The index of *doc* where parsing failed.
.. attribute:: lineno
The line corresponding to *pos*.
.. attribute:: colno
The column corresponding to *pos*.
.. versionchanged:: next
Added the *msg*, *doc* and *pos* parameters.
Added the :attr:`msg`, :attr:`doc`, :attr:`pos`, :attr:`lineno` and :attr:`colno` attributes.
.. deprecated:: next
Passing free-form positional arguments is deprecated.
Examples

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@ -49,7 +49,9 @@ class TestError(unittest.TestCase):
self.assertEqual(str(exc_info.exception), "Expected str object, not 'bool'")
def test_module_name(self):
self.assertEqual(tomllib.TOMLDecodeError().__module__, tomllib.__name__)
self.assertEqual(
tomllib.TOMLDecodeError("", "", 0).__module__, tomllib.__name__
)
def test_invalid_parse_float(self):
def dict_returner(s: str) -> dict:
@ -64,3 +66,33 @@ class TestError(unittest.TestCase):
self.assertEqual(
str(exc_info.exception), "parse_float must not return dicts or lists"
)
def test_deprecated_tomldecodeerror(self):
for args in [
(),
("err msg",),
(None,),
(None, "doc"),
("err msg", None),
(None, "doc", None),
("err msg", "doc", None),
("one", "two", "three", "four"),
("one", "two", 3, "four", "five"),
]:
with self.assertWarns(DeprecationWarning):
e = tomllib.TOMLDecodeError(*args) # type: ignore[arg-type]
self.assertEqual(e.args, args)
def test_tomldecodeerror(self):
msg = "error parsing"
doc = "v=1\n[table]\nv='val'"
pos = 13
formatted_msg = "error parsing (at line 3, column 2)"
e = tomllib.TOMLDecodeError(msg, doc, pos)
self.assertEqual(e.args, (formatted_msg,))
self.assertEqual(str(e), formatted_msg)
self.assertEqual(e.msg, msg)
self.assertEqual(e.doc, doc)
self.assertEqual(e.pos, pos)
self.assertEqual(e.lineno, 3)
self.assertEqual(e.colno, 2)

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@ -8,6 +8,7 @@ from collections.abc import Iterable
import string
from types import MappingProxyType
from typing import Any, BinaryIO, NamedTuple
import warnings
from ._re import (
RE_DATETIME,
@ -50,8 +51,68 @@ BASIC_STR_ESCAPE_REPLACEMENTS = MappingProxyType(
)
class DEPRECATED_DEFAULT:
"""Sentinel to be used as default arg during deprecation
period of TOMLDecodeError's free-form arguments."""
class TOMLDecodeError(ValueError):
"""An error raised if a document is not valid TOML."""
"""An error raised if a document is not valid TOML.
Adds the following attributes to ValueError:
msg: The unformatted error message
doc: The TOML document being parsed
pos: The index of doc where parsing failed
lineno: The line corresponding to pos
colno: The column corresponding to pos
"""
def __init__(
self,
msg: str = DEPRECATED_DEFAULT, # type: ignore[assignment]
doc: str = DEPRECATED_DEFAULT, # type: ignore[assignment]
pos: Pos = DEPRECATED_DEFAULT, # type: ignore[assignment]
*args: Any,
):
if (
args
or not isinstance(msg, str)
or not isinstance(doc, str)
or not isinstance(pos, int)
):
warnings.warn(
"Free-form arguments for TOMLDecodeError are deprecated. "
"Please set 'msg' (str), 'doc' (str) and 'pos' (int) arguments only.",
DeprecationWarning,
stacklevel=2,
)
if pos is not DEPRECATED_DEFAULT: # type: ignore[comparison-overlap]
args = pos, *args
if doc is not DEPRECATED_DEFAULT: # type: ignore[comparison-overlap]
args = doc, *args
if msg is not DEPRECATED_DEFAULT: # type: ignore[comparison-overlap]
args = msg, *args
ValueError.__init__(self, *args)
return
lineno = doc.count("\n", 0, pos) + 1
if lineno == 1:
colno = pos + 1
else:
colno = pos - doc.rindex("\n", 0, pos)
if pos >= len(doc):
coord_repr = "end of document"
else:
coord_repr = f"line {lineno}, column {colno}"
errmsg = f"{msg} (at {coord_repr})"
ValueError.__init__(self, errmsg)
self.msg = msg
self.doc = doc
self.pos = pos
self.lineno = lineno
self.colno = colno
def load(fp: BinaryIO, /, *, parse_float: ParseFloat = float) -> dict[str, Any]:
@ -118,7 +179,7 @@ def loads(s: str, /, *, parse_float: ParseFloat = float) -> dict[str, Any]: # n
pos, header = create_dict_rule(src, pos, out)
pos = skip_chars(src, pos, TOML_WS)
elif char != "#":
raise suffixed_err(src, pos, "Invalid statement")
raise TOMLDecodeError("Invalid statement", src, pos)
# 3. Skip comment
pos = skip_comment(src, pos)
@ -129,8 +190,8 @@ def loads(s: str, /, *, parse_float: ParseFloat = float) -> dict[str, Any]: # n
except IndexError:
break
if char != "\n":
raise suffixed_err(
src, pos, "Expected newline or end of document after a statement"
raise TOMLDecodeError(
"Expected newline or end of document after a statement", src, pos
)
pos += 1
@ -256,12 +317,12 @@ def skip_until(
except ValueError:
new_pos = len(src)
if error_on_eof:
raise suffixed_err(src, new_pos, f"Expected {expect!r}") from None
raise TOMLDecodeError(f"Expected {expect!r}", src, new_pos) from None
if not error_on.isdisjoint(src[pos:new_pos]):
while src[pos] not in error_on:
pos += 1
raise suffixed_err(src, pos, f"Found invalid character {src[pos]!r}")
raise TOMLDecodeError(f"Found invalid character {src[pos]!r}", src, pos)
return new_pos
@ -292,15 +353,17 @@ def create_dict_rule(src: str, pos: Pos, out: Output) -> tuple[Pos, Key]:
pos, key = parse_key(src, pos)
if out.flags.is_(key, Flags.EXPLICIT_NEST) or out.flags.is_(key, Flags.FROZEN):
raise suffixed_err(src, pos, f"Cannot declare {key} twice")
raise TOMLDecodeError(f"Cannot declare {key} twice", src, pos)
out.flags.set(key, Flags.EXPLICIT_NEST, recursive=False)
try:
out.data.get_or_create_nest(key)
except KeyError:
raise suffixed_err(src, pos, "Cannot overwrite a value") from None
raise TOMLDecodeError("Cannot overwrite a value", src, pos) from None
if not src.startswith("]", pos):
raise suffixed_err(src, pos, "Expected ']' at the end of a table declaration")
raise TOMLDecodeError(
"Expected ']' at the end of a table declaration", src, pos
)
return pos + 1, key
@ -310,7 +373,7 @@ def create_list_rule(src: str, pos: Pos, out: Output) -> tuple[Pos, Key]:
pos, key = parse_key(src, pos)
if out.flags.is_(key, Flags.FROZEN):
raise suffixed_err(src, pos, f"Cannot mutate immutable namespace {key}")
raise TOMLDecodeError(f"Cannot mutate immutable namespace {key}", src, pos)
# Free the namespace now that it points to another empty list item...
out.flags.unset_all(key)
# ...but this key precisely is still prohibited from table declaration
@ -318,10 +381,12 @@ def create_list_rule(src: str, pos: Pos, out: Output) -> tuple[Pos, Key]:
try:
out.data.append_nest_to_list(key)
except KeyError:
raise suffixed_err(src, pos, "Cannot overwrite a value") from None
raise TOMLDecodeError("Cannot overwrite a value", src, pos) from None
if not src.startswith("]]", pos):
raise suffixed_err(src, pos, "Expected ']]' at the end of an array declaration")
raise TOMLDecodeError(
"Expected ']]' at the end of an array declaration", src, pos
)
return pos + 2, key
@ -336,22 +401,22 @@ def key_value_rule(
for cont_key in relative_path_cont_keys:
# Check that dotted key syntax does not redefine an existing table
if out.flags.is_(cont_key, Flags.EXPLICIT_NEST):
raise suffixed_err(src, pos, f"Cannot redefine namespace {cont_key}")
raise TOMLDecodeError(f"Cannot redefine namespace {cont_key}", src, pos)
# Containers in the relative path can't be opened with the table syntax or
# dotted key/value syntax in following table sections.
out.flags.add_pending(cont_key, Flags.EXPLICIT_NEST)
if out.flags.is_(abs_key_parent, Flags.FROZEN):
raise suffixed_err(
src, pos, f"Cannot mutate immutable namespace {abs_key_parent}"
raise TOMLDecodeError(
f"Cannot mutate immutable namespace {abs_key_parent}", src, pos
)
try:
nest = out.data.get_or_create_nest(abs_key_parent)
except KeyError:
raise suffixed_err(src, pos, "Cannot overwrite a value") from None
raise TOMLDecodeError("Cannot overwrite a value", src, pos) from None
if key_stem in nest:
raise suffixed_err(src, pos, "Cannot overwrite a value")
raise TOMLDecodeError("Cannot overwrite a value", src, pos)
# Mark inline table and array namespaces recursively immutable
if isinstance(value, (dict, list)):
out.flags.set(header + key, Flags.FROZEN, recursive=True)
@ -368,7 +433,7 @@ def parse_key_value_pair(
except IndexError:
char = None
if char != "=":
raise suffixed_err(src, pos, "Expected '=' after a key in a key/value pair")
raise TOMLDecodeError("Expected '=' after a key in a key/value pair", src, pos)
pos += 1
pos = skip_chars(src, pos, TOML_WS)
pos, value = parse_value(src, pos, parse_float)
@ -406,7 +471,7 @@ def parse_key_part(src: str, pos: Pos) -> tuple[Pos, str]:
return parse_literal_str(src, pos)
if char == '"':
return parse_one_line_basic_str(src, pos)
raise suffixed_err(src, pos, "Invalid initial character for a key part")
raise TOMLDecodeError("Invalid initial character for a key part", src, pos)
def parse_one_line_basic_str(src: str, pos: Pos) -> tuple[Pos, str]:
@ -430,7 +495,7 @@ def parse_array(src: str, pos: Pos, parse_float: ParseFloat) -> tuple[Pos, list]
if c == "]":
return pos + 1, array
if c != ",":
raise suffixed_err(src, pos, "Unclosed array")
raise TOMLDecodeError("Unclosed array", src, pos)
pos += 1
pos = skip_comments_and_array_ws(src, pos)
@ -450,20 +515,20 @@ def parse_inline_table(src: str, pos: Pos, parse_float: ParseFloat) -> tuple[Pos
pos, key, value = parse_key_value_pair(src, pos, parse_float)
key_parent, key_stem = key[:-1], key[-1]
if flags.is_(key, Flags.FROZEN):
raise suffixed_err(src, pos, f"Cannot mutate immutable namespace {key}")
raise TOMLDecodeError(f"Cannot mutate immutable namespace {key}", src, pos)
try:
nest = nested_dict.get_or_create_nest(key_parent, access_lists=False)
except KeyError:
raise suffixed_err(src, pos, "Cannot overwrite a value") from None
raise TOMLDecodeError("Cannot overwrite a value", src, pos) from None
if key_stem in nest:
raise suffixed_err(src, pos, f"Duplicate inline table key {key_stem!r}")
raise TOMLDecodeError(f"Duplicate inline table key {key_stem!r}", src, pos)
nest[key_stem] = value
pos = skip_chars(src, pos, TOML_WS)
c = src[pos : pos + 1]
if c == "}":
return pos + 1, nested_dict.dict
if c != ",":
raise suffixed_err(src, pos, "Unclosed inline table")
raise TOMLDecodeError("Unclosed inline table", src, pos)
if isinstance(value, (dict, list)):
flags.set(key, Flags.FROZEN, recursive=True)
pos += 1
@ -485,7 +550,7 @@ def parse_basic_str_escape(
except IndexError:
return pos, ""
if char != "\n":
raise suffixed_err(src, pos, "Unescaped '\\' in a string")
raise TOMLDecodeError("Unescaped '\\' in a string", src, pos)
pos += 1
pos = skip_chars(src, pos, TOML_WS_AND_NEWLINE)
return pos, ""
@ -496,7 +561,7 @@ def parse_basic_str_escape(
try:
return pos, BASIC_STR_ESCAPE_REPLACEMENTS[escape_id]
except KeyError:
raise suffixed_err(src, pos, "Unescaped '\\' in a string") from None
raise TOMLDecodeError("Unescaped '\\' in a string", src, pos) from None
def parse_basic_str_escape_multiline(src: str, pos: Pos) -> tuple[Pos, str]:
@ -506,11 +571,13 @@ def parse_basic_str_escape_multiline(src: str, pos: Pos) -> tuple[Pos, str]:
def parse_hex_char(src: str, pos: Pos, hex_len: int) -> tuple[Pos, str]:
hex_str = src[pos : pos + hex_len]
if len(hex_str) != hex_len or not HEXDIGIT_CHARS.issuperset(hex_str):
raise suffixed_err(src, pos, "Invalid hex value")
raise TOMLDecodeError("Invalid hex value", src, pos)
pos += hex_len
hex_int = int(hex_str, 16)
if not is_unicode_scalar_value(hex_int):
raise suffixed_err(src, pos, "Escaped character is not a Unicode scalar value")
raise TOMLDecodeError(
"Escaped character is not a Unicode scalar value", src, pos
)
return pos, chr(hex_int)
@ -567,7 +634,7 @@ def parse_basic_str(src: str, pos: Pos, *, multiline: bool) -> tuple[Pos, str]:
try:
char = src[pos]
except IndexError:
raise suffixed_err(src, pos, "Unterminated string") from None
raise TOMLDecodeError("Unterminated string", src, pos) from None
if char == '"':
if not multiline:
return pos + 1, result + src[start_pos:pos]
@ -582,7 +649,7 @@ def parse_basic_str(src: str, pos: Pos, *, multiline: bool) -> tuple[Pos, str]:
start_pos = pos
continue
if char in error_on:
raise suffixed_err(src, pos, f"Illegal character {char!r}")
raise TOMLDecodeError(f"Illegal character {char!r}", src, pos)
pos += 1
@ -630,7 +697,7 @@ def parse_value( # noqa: C901
try:
datetime_obj = match_to_datetime(datetime_match)
except ValueError as e:
raise suffixed_err(src, pos, "Invalid date or datetime") from e
raise TOMLDecodeError("Invalid date or datetime", src, pos) from e
return datetime_match.end(), datetime_obj
localtime_match = RE_LOCALTIME.match(src, pos)
if localtime_match:
@ -651,24 +718,7 @@ def parse_value( # noqa: C901
if first_four in {"-inf", "+inf", "-nan", "+nan"}:
return pos + 4, parse_float(first_four)
raise suffixed_err(src, pos, "Invalid value")
def suffixed_err(src: str, pos: Pos, msg: str) -> TOMLDecodeError:
"""Return a `TOMLDecodeError` where error message is suffixed with
coordinates in source."""
def coord_repr(src: str, pos: Pos) -> str:
if pos >= len(src):
return "end of document"
line = src.count("\n", 0, pos) + 1
if line == 1:
column = pos + 1
else:
column = pos - src.rindex("\n", 0, pos)
return f"line {line}, column {column}"
return TOMLDecodeError(f"{msg} (at {coord_repr(src, pos)})")
raise TOMLDecodeError("Invalid value", src, pos)
def is_unicode_scalar_value(codepoint: int) -> bool:

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@ -0,0 +1,2 @@
Add ``msg``, ``doc``, ``pos``, ``lineno`` and ``colno`` attributes to :exc:`tomllib.TOMLDecodeError`.
Deprecate instantiating with free-form arguments.