python-peps/check-peps.py

618 lines
23 KiB
Python
Executable File

#!/usr/bin/env python3
# This file is placed in the public domain or under the
# CC0-1.0-Universal license, whichever is more permissive.
"""check-peps: Check PEPs for common mistakes.
Usage: check-peps [-d | --detailed] <PEP files...>
Only the PEPs specified are checked.
If none are specified, all PEPs are checked.
Use "--detailed" to show the contents of lines where errors were found.
"""
from __future__ import annotations
import datetime as dt
import re
import sys
from pathlib import Path
TYPE_CHECKING = False
if TYPE_CHECKING:
from collections.abc import Iterable, Iterator, KeysView, Sequence
from typing import TypeAlias
# (line number, warning message)
Message: TypeAlias = tuple[int, str]
MessageIterator: TypeAlias = Iterator[Message]
# get the directory with the PEP sources
ROOT_DIR = Path(__file__).resolve().parent
PEP_ROOT = ROOT_DIR / "peps"
# See PEP 12 for the order
# Note we retain "BDFL-Delegate"
ALL_HEADERS = (
"PEP",
"Title",
"Version",
"Last-Modified",
"Author",
"Sponsor",
"BDFL-Delegate", "PEP-Delegate",
"Discussions-To",
"Status",
"Type",
"Topic",
"Content-Type",
"Requires",
"Created",
"Python-Version",
"Post-History",
"Replaces",
"Superseded-By",
"Resolution",
)
REQUIRED_HEADERS = frozenset({"PEP", "Title", "Author", "Status", "Type", "Created"})
# See PEP 1 for the full list
ALL_STATUSES = frozenset({
"Accepted",
"Active",
"April Fool!",
"Deferred",
"Draft",
"Final",
"Provisional",
"Rejected",
"Superseded",
"Withdrawn",
})
# PEPs that are allowed to link directly to PEPs
SKIP_DIRECT_PEP_LINK_CHECK = frozenset({"0009", "0287", "0676", "0684", "8001"})
DEFAULT_FLAGS = re.ASCII | re.IGNORECASE # Insensitive latin
# any sequence of letters or '-', followed by a single ':' and a space or end of line
HEADER_PATTERN = re.compile(r"^([a-z\-]+):(?: |$)", DEFAULT_FLAGS)
# any sequence of unicode letters or legal special characters
NAME_PATTERN = re.compile(r"(?:[^\W\d_]|[ ',\-.])+(?: |$)")
# any sequence of ASCII letters, digits, or legal special characters
EMAIL_LOCAL_PART_PATTERN = re.compile(r"[\w!#$%&'*+\-/=?^{|}~.]+", DEFAULT_FLAGS)
DISCOURSE_THREAD_PATTERN = re.compile(r"([\w\-]+/)?\d+", DEFAULT_FLAGS)
DISCOURSE_POST_PATTERN = re.compile(r"([\w\-]+/)?\d+(/\d+)?", DEFAULT_FLAGS)
MAILMAN_2_PATTERN = re.compile(r"[\w\-]+/\d{4}-[a-z]+/\d+\.html", DEFAULT_FLAGS)
MAILMAN_3_THREAD_PATTERN = re.compile(r"[\w\-]+@python\.org/thread/[a-z0-9]+/?", DEFAULT_FLAGS)
MAILMAN_3_MESSAGE_PATTERN = re.compile(r"[\w\-]+@python\.org/message/[a-z0-9]+/?(#[a-z0-9]+)?", DEFAULT_FLAGS)
# Controlled by the "--detailed" flag
DETAILED_ERRORS = False
def check(filenames: Sequence[str] = (), /) -> int:
"""The main entry-point."""
if filenames:
filenames = map(Path, filenames)
else:
filenames = PEP_ROOT.glob("pep-????.rst")
if (count := sum(map(check_file, filenames))) > 0:
s = "s" * (count != 1)
print(f"check-peps failed: {count} error{s}", file=sys.stderr)
return 1
return 0
def check_file(filename: Path, /) -> int:
filename = filename.resolve()
try:
content = filename.read_text(encoding="utf-8")
except FileNotFoundError:
return _output_error(filename, [""], [(0, "Could not read PEP!")])
else:
lines = content.splitlines()
return _output_error(filename, lines, check_peps(filename, lines))
def check_peps(filename: Path, lines: Sequence[str], /) -> MessageIterator:
yield from check_headers(lines)
for line_num, line in enumerate(lines, start=1):
if filename.stem.removeprefix("pep-") in SKIP_DIRECT_PEP_LINK_CHECK:
continue
yield from check_direct_links(line_num, line.lstrip())
def check_headers(lines: Sequence[str], /) -> MessageIterator:
yield from _validate_pep_number(next(iter(lines), ""))
found_headers = {}
line_num = 0
for line_num, line in enumerate(lines, start=1):
if line.strip() == "":
headers_end_line_num = line_num
break
if match := HEADER_PATTERN.match(line):
header = match[1]
if header in ALL_HEADERS:
if header not in found_headers:
found_headers[match[1]] = line_num
else:
yield line_num, f"Must not have duplicate header: {header} "
else:
yield line_num, f"Must not have invalid header: {header}"
else:
headers_end_line_num = line_num
yield from _validate_required_headers(found_headers.keys())
shifted_line_nums = list(found_headers.values())[1:]
for i, (header, line_num) in enumerate(found_headers.items()):
start = line_num - 1
end = headers_end_line_num - 1
if i < len(found_headers) - 1:
end = shifted_line_nums[i] - 1
remainder = "\n".join(lines[start:end]).removeprefix(f"{header}:")
if remainder != "":
if remainder[0] not in {" ", "\n"}:
yield line_num, f"Headers must have a space after the colon: {header}"
remainder = remainder.lstrip()
yield from _validate_header(header, line_num, remainder)
def _validate_header(header: str, line_num: int, content: str) -> MessageIterator:
if header == "Title":
yield from _validate_title(line_num, content)
elif header == "Author":
yield from _validate_author(line_num, content)
elif header == "Sponsor":
yield from _validate_sponsor(line_num, content)
elif header in {"BDFL-Delegate", "PEP-Delegate"}:
yield from _validate_delegate(line_num, content)
elif header == "Discussions-To":
yield from _validate_discussions_to(line_num, content)
elif header == "Status":
yield from _validate_status(line_num, content)
elif header == "Type":
yield from _validate_type(line_num, content)
elif header == "Topic":
yield from _validate_topic(line_num, content)
elif header == "Content-Type":
yield from _validate_content_type(line_num, content)
elif header in {"Requires", "Replaces", "Superseded-By"}:
yield from _validate_pep_references(line_num, content)
elif header == "Created":
yield from _validate_created(line_num, content)
elif header == "Python-Version":
yield from _validate_python_version(line_num, content)
elif header == "Post-History":
yield from _validate_post_history(line_num, content)
elif header == "Resolution":
yield from _validate_resolution(line_num, content)
def check_direct_links(line_num: int, line: str) -> MessageIterator:
"""Check that PEPs and RFCs aren't linked directly"""
line = line.lower()
if "dev/peps/pep-" in line or "peps.python.org/pep-" in line:
yield line_num, "Use the :pep:`NNN` role to refer to PEPs"
if "rfc-editor.org/rfc/" in line or "ietf.org/doc/html/rfc" in line:
yield line_num, "Use the :rfc:`NNN` role to refer to RFCs"
def _output_error(filename: Path, lines: Sequence[str], errors: Iterable[Message]) -> int:
relative_filename = filename.relative_to(ROOT_DIR)
err_count = 0
for line_num, msg in errors:
err_count += 1
print(f"{relative_filename}:{line_num}: {msg}")
if not DETAILED_ERRORS:
continue
line = lines[line_num - 1]
print(" |")
print(f"{line_num: >4} | '{line}'")
print(" |")
return err_count
###########################
# PEP Header Validators #
###########################
def _validate_required_headers(found_headers: KeysView[str]) -> MessageIterator:
"""PEPs must have all required headers, in the PEP 12 order"""
if missing := REQUIRED_HEADERS.difference(found_headers):
for missing_header in sorted(missing, key=ALL_HEADERS.index):
yield 1, f"Must have required header: {missing_header}"
ordered_headers = sorted(found_headers, key=ALL_HEADERS.index)
if list(found_headers) != ordered_headers:
order_str = ", ".join(ordered_headers)
yield 1, "Headers must be in PEP 12 order. Correct order: " + order_str
def _validate_pep_number(line: str) -> MessageIterator:
"""'PEP' header must be a number 1-9999"""
if not line.startswith("PEP: "):
yield 1, "PEP must begin with the 'PEP:' header"
return
pep_number = line.removeprefix("PEP: ").lstrip()
yield from _pep_num(1, pep_number, "'PEP:' header")
def _validate_title(line_num: int, line: str) -> MessageIterator:
"""'Title' must be 1-79 characters"""
if len(line) == 0:
yield line_num, "PEP must have a title"
elif len(line) > 79:
yield line_num, "PEP title must be less than 80 characters"
def _validate_author(line_num: int, body: str) -> MessageIterator:
"""'Author' must be list of 'Name <email@example.com>, …'"""
lines = body.split("\n")
for offset, line in enumerate(lines):
if offset >= 1 and line[:9].isspace():
# Checks for:
# Author: Alice
# Bob
# ^^^^
# Note that len("Author: ") == 8
yield line_num + offset, "Author line must not be over-indented"
if offset < len(lines) - 1:
if not line.endswith(","):
yield line_num + offset, "Author continuation lines must end with a comma"
for part in line.removesuffix(",").split(", "):
yield from _email(line_num + offset, part, "Author")
def _validate_sponsor(line_num: int, line: str) -> MessageIterator:
"""'Sponsor' must have format 'Name <email@example.com>'"""
yield from _email(line_num, line, "Sponsor")
def _validate_delegate(line_num: int, line: str) -> MessageIterator:
"""'Delegate' must have format 'Name <email@example.com>'"""
if line == "":
return
# PEP 451
if ", " in line:
for part in line.removesuffix(",").split(", "):
yield from _email(line_num, part, "Delegate")
return
yield from _email(line_num, line, "Delegate")
def _validate_discussions_to(line_num: int, line: str) -> MessageIterator:
"""'Discussions-To' must be a thread URL"""
yield from _thread(line_num, line, "Discussions-To", discussions_to=True)
if line.startswith("https://"):
return
for suffix in "@python.org", "@googlegroups.com":
if line.endswith(suffix):
remainder = line.removesuffix(suffix)
if re.fullmatch(r"[\w\-]+", remainder) is None:
yield line_num, "Discussions-To must be a valid mailing list"
return
yield line_num, "Discussions-To must be a valid thread URL or mailing list"
def _validate_status(line_num: int, line: str) -> MessageIterator:
"""'Status' must be a valid PEP status"""
if line not in ALL_STATUSES:
yield line_num, "Status must be a valid PEP status"
def _validate_type(line_num: int, line: str) -> MessageIterator:
"""'Type' must be a valid PEP type"""
if line not in {"Standards Track", "Informational", "Process"}:
yield line_num, "Type must be a valid PEP type"
def _validate_topic(line_num: int, line: str) -> MessageIterator:
"""'Topic' must be for a valid sub-index"""
topics = line.split(", ")
unique_topics = set(topics)
if len(topics) > len(unique_topics):
yield line_num, "Topic must not contain duplicates"
if unique_topics - {"Governance", "Packaging", "Typing", "Release"}:
if not all(map(str.istitle, unique_topics)):
yield line_num, "Topic must be properly capitalised (Title Case)"
if unique_topics - {"governance", "packaging", "typing", "release"}:
yield line_num, "Topic must be for a valid sub-index"
if sorted(topics) != topics:
yield line_num, "Topic must be sorted lexicographically"
def _validate_content_type(line_num: int, line: str) -> MessageIterator:
"""'Content-Type' must be 'text/x-rst'"""
if line != "text/x-rst":
yield line_num, "Content-Type must be 'text/x-rst'"
def _validate_pep_references(line_num: int, line: str) -> MessageIterator:
"""`Requires`/`Replaces`/`Superseded-By` must be 'NNN' PEP IDs"""
line = line.removesuffix(",").rstrip()
if line.count(", ") != line.count(","):
yield line_num, "PEP references must be separated by comma-spaces (', ')"
return
references = line.split(", ")
for reference in references:
yield from _pep_num(line_num, reference, "PEP reference")
def _validate_created(line_num: int, line: str) -> MessageIterator:
"""'Created' must be a 'DD-mmm-YYYY' date"""
yield from _date(line_num, line, "Created")
def _validate_python_version(line_num: int, line: str) -> MessageIterator:
"""'Python-Version' must be an ``X.Y[.Z]`` version"""
versions = line.split(", ")
for version in versions:
if version.count(".") not in {1, 2}:
yield line_num, f"Python-Version must have two or three segments: {version}"
continue
try:
major, minor, micro = version.split(".", 2)
except ValueError:
major, minor = version.split(".", 1)
micro = ""
if major not in "123":
yield line_num, f"Python-Version major part must be 1, 2, or 3: {version}"
if not _is_digits(minor) and minor != "x":
yield line_num, f"Python-Version minor part must be numeric: {version}"
elif minor != "0" and minor[0] == "0":
yield line_num, f"Python-Version minor part must not have leading zeros: {version}"
if micro == "":
return
if minor == "x":
yield line_num, f"Python-Version micro part must be empty if minor part is 'x': {version}"
elif micro[0] == "0":
yield line_num, f"Python-Version micro part must not have leading zeros: {version}"
elif not _is_digits(micro):
yield line_num, f"Python-Version micro part must be numeric: {version}"
def _validate_post_history(line_num: int, body: str) -> MessageIterator:
"""'Post-History' must be '`DD-mmm-YYYY <Thread URL>`__, …' or `DD-mmm-YYYY`"""
if body == "":
return
for offset, line in enumerate(body.removesuffix(",").split("\n"), start=line_num):
for post in line.removesuffix(",").strip().split(", "):
prefix, postfix = (post.startswith("`"), post.endswith(">`__"))
if not prefix and not postfix:
yield from _date(offset, post, "Post-History")
elif prefix and postfix:
post_date, post_url = post[1:-4].split(" <")
yield from _date(offset, post_date, "Post-History")
yield from _thread(offset, post_url, "Post-History")
else:
yield offset, "post line must be a date or both start with “`” and end with “>`__”"
def _validate_resolution(line_num: int, line: str) -> MessageIterator:
"""'Resolution' must be a direct thread/message URL or a link with a date."""
prefix, postfix = (line.startswith("`"), line.endswith(">`__"))
if not prefix and not postfix:
yield from _thread(line_num, line, "Resolution", allow_message=True)
elif prefix and postfix:
post_date, post_url = line[1:-4].split(" <")
yield from _date(line_num, post_date, "Resolution")
yield from _thread(line_num, post_url, "Resolution", allow_message=True)
else:
yield line_num, "Resolution line must be a link or both start with “`” and end with “>`__”"
########################
# Validation Helpers #
########################
def _pep_num(line_num: int, pep_number: str, prefix: str) -> MessageIterator:
if pep_number == "":
yield line_num, f"{prefix} must not be blank: {pep_number!r}"
return
if pep_number.startswith("0") and pep_number != "0":
yield line_num, f"{prefix} must not contain leading zeros: {pep_number!r}"
if not _is_digits(pep_number):
yield line_num, f"{prefix} must be numeric: {pep_number!r}"
elif not 0 <= int(pep_number) <= 9999:
yield line_num, f"{prefix} must be between 0 and 9999: {pep_number!r}"
def _is_digits(string: str) -> bool:
"""Match a string of ASCII digits ([0-9]+)."""
return string.isascii() and string.isdigit()
def _email(line_num: int, author_email: str, prefix: str) -> MessageIterator:
author_email = author_email.strip()
if author_email.count("<") > 1:
msg = f"{prefix} entries must not contain multiple '<': {author_email!r}"
yield line_num, msg
if author_email.count(">") > 1:
msg = f"{prefix} entries must not contain multiple '>': {author_email!r}"
yield line_num, msg
if author_email.count("@") > 1:
msg = f"{prefix} entries must not contain multiple '@': {author_email!r}"
yield line_num, msg
author = author_email.split("<", 1)[0].rstrip()
if NAME_PATTERN.fullmatch(author) is None:
msg = f"{prefix} entries must begin with a valid 'Name': {author_email!r}"
yield line_num, msg
return
email_text = author_email.removeprefix(author)
if not email_text:
# Does not have the optional email part
return
if not email_text.startswith(" <") or not email_text.endswith(">"):
msg = f"{prefix} entries must be formatted as 'Name <email@example.com>': {author_email!r}"
yield line_num, msg
email_text = email_text.removeprefix(" <").removesuffix(">")
if "@" in email_text:
local, domain = email_text.rsplit("@", 1)
elif " at " in email_text:
local, domain = email_text.rsplit(" at ", 1)
else:
yield line_num, f"{prefix} entries must contain a valid email address: {author_email!r}"
return
if EMAIL_LOCAL_PART_PATTERN.fullmatch(local) is None or _invalid_domain(domain):
yield line_num, f"{prefix} entries must contain a valid email address: {author_email!r}"
def _invalid_domain(domain_part: str) -> bool:
*labels, root = domain_part.split(".")
for label in labels:
if not label.replace("-", "").isalnum():
return True
return not root.isalnum() or not root.isascii()
def _thread(line_num: int, url: str, prefix: str, *, allow_message: bool = False, discussions_to: bool = False) -> MessageIterator:
if allow_message and discussions_to:
msg = "allow_message and discussions_to cannot both be True"
raise ValueError(msg)
msg = f"{prefix} must be a valid thread URL"
if not url.startswith("https://"):
if not discussions_to:
yield line_num, msg
return
if url.startswith("https://discuss.python.org/t/"):
remainder = url.removeprefix("https://discuss.python.org/t/").removesuffix("/")
# Discussions-To links must be the thread itself, not a post
if discussions_to:
# The equivalent pattern is similar to '([\w\-]+/)?\d+',
# but the topic name must contain a non-numeric character
# We use ``str.rpartition`` as the topic name is optional
topic_name, _, topic_id = remainder.rpartition("/")
if topic_name == '' and _is_digits(topic_id):
return
topic_name = topic_name.replace("-", "0").replace("_", "0")
# the topic name must not be entirely numeric
valid_topic_name = not _is_digits(topic_name) and topic_name.isalnum()
if valid_topic_name and _is_digits(topic_id):
return
else:
# The equivalent pattern is similar to '([\w\-]+/)?\d+(/\d+)?',
# but the topic name must contain a non-numeric character
if remainder.count("/") == 2:
# When there are three parts, the URL must be "topic-name/topic-id/post-id".
topic_name, topic_id, post_id = remainder.rsplit("/", 2)
topic_name = topic_name.replace("-", "0").replace("_", "0")
valid_topic_name = not _is_digits(topic_name) and topic_name.isalnum()
if valid_topic_name and _is_digits(topic_id) and _is_digits(post_id):
# the topic name must not be entirely numeric
return
elif remainder.count("/") == 1:
# When there are only two parts, there's an ambiguity between
# "topic-name/topic-id" and "topic-id/post-id".
# We disambiguate by checking if the LHS is a valid name and
# the RHS is a valid topic ID (for the former),
# and then if both the LHS and RHS are valid IDs (for the latter).
left, right = remainder.rsplit("/")
left = left.replace("-", "0").replace("_", "0")
# the topic name must not be entirely numeric
left_is_name = not _is_digits(left) and left.isalnum()
if left_is_name and _is_digits(right):
return
elif _is_digits(left) and _is_digits(right):
return
else:
# When there's only one part, it must be a valid topic ID.
if _is_digits(remainder):
return
if url.startswith("https://mail.python.org/pipermail/"):
remainder = url.removeprefix("https://mail.python.org/pipermail/")
if MAILMAN_2_PATTERN.fullmatch(remainder) is not None:
return
if url.startswith("https://mail.python.org/archives/list/"):
remainder = url.removeprefix("https://mail.python.org/archives/list/")
if allow_message and MAILMAN_3_MESSAGE_PATTERN.fullmatch(remainder) is not None:
return
if MAILMAN_3_THREAD_PATTERN.fullmatch(remainder) is not None:
return
yield line_num, msg
def _date(line_num: int, date_str: str, prefix: str) -> MessageIterator:
try:
parsed_date = dt.datetime.strptime(date_str, "%d-%b-%Y")
except ValueError:
yield line_num, f"{prefix} must be a 'DD-mmm-YYYY' date: {date_str!r}"
return
else:
if date_str[1] == "-": # Date must be zero-padded
yield line_num, f"{prefix} must be a 'DD-mmm-YYYY' date: {date_str!r}"
return
if parsed_date.year < 1990:
yield line_num, f"{prefix} must not be before Python was invented: {date_str!r}"
if parsed_date > (dt.datetime.now() + dt.timedelta(days=14)):
yield line_num, f"{prefix} must not be in the future: {date_str!r}"
if __name__ == "__main__":
if {"-h", "--help", "-?"}.intersection(sys.argv[1:]):
print(__doc__, file=sys.stderr)
raise SystemExit(0)
files = {}
for arg in sys.argv[1:]:
if not arg.startswith("-"):
files[arg] = None
elif arg in {"-d", "--detailed"}:
DETAILED_ERRORS = True
else:
print(f"Unknown option: {arg!r}", file=sys.stderr)
raise SystemExit(1)
raise SystemExit(check(files))