herdr/scripts/changelog.py

159 lines
4.7 KiB
Python

#!/usr/bin/env python3
from __future__ import annotations
import argparse
import re
import sys
from dataclasses import dataclass
from datetime import date
from pathlib import Path
SECTION_RE = re.compile(r"^##\s+(?:\[(?P<bracketed>[^\]]+)\]|(?P<plain>.+?))\s*$", re.MULTILINE)
VERSION_WITH_DATE_RE = re.compile(r"^(?P<version>.+?)\s+-\s+\d{4}-\d{2}-\d{2}$")
@dataclass(frozen=True)
class Section:
title: str
start: int
end: int
body_start: int
class ChangelogError(ValueError):
pass
def normalize_title(raw_title: str) -> str:
title = raw_title.strip()
match = VERSION_WITH_DATE_RE.match(title)
if match:
title = match.group("version").strip()
if title.startswith("[") and title.endswith("]"):
title = title[1:-1].strip()
return title
def parse_sections(text: str) -> list[Section]:
matches = list(SECTION_RE.finditer(text))
sections: list[Section] = []
for index, match in enumerate(matches):
title = normalize_title(match.group("bracketed") or match.group("plain") or "")
end = matches[index + 1].start() if index + 1 < len(matches) else len(text)
body_start = match.end()
if body_start < len(text) and text[body_start : body_start + 1] == "\n":
body_start += 1
sections.append(Section(title=title, start=match.start(), end=end, body_start=body_start))
return sections
def find_section(text: str, wanted_title: str) -> Section:
for section in parse_sections(text):
if section.title == wanted_title:
return section
raise ChangelogError(f"section not found: {wanted_title}")
def extract_section_body(text: str, wanted_title: str) -> str:
section = find_section(text, wanted_title)
body = text[section.body_start : section.end].strip("\n")
if not body.strip():
raise ChangelogError(f"section is empty: {wanted_title}")
return body + "\n"
def prepare_release(text: str, version: str, release_date: str) -> str:
unreleased = None
existing_version = False
for section in parse_sections(text):
if section.title == "Unreleased":
unreleased = section
if section.title == version:
existing_version = True
if existing_version:
raise ChangelogError(f"version already exists in changelog: {version}")
if unreleased is None:
raise ChangelogError("missing Unreleased section")
unreleased_body = text[unreleased.body_start : unreleased.end].strip("\n")
if not unreleased_body.strip():
raise ChangelogError("Unreleased section is empty")
prefix = text[: unreleased.start].rstrip("\n")
suffix = text[unreleased.end :].strip("\n")
rebuilt = f"## Unreleased\n\n## [{version}] - {release_date}\n\n{unreleased_body}"
if suffix:
rebuilt += f"\n\n{suffix}"
if prefix:
return f"{prefix}\n\n{rebuilt}\n"
return rebuilt + "\n"
def load_text(path: Path) -> str:
try:
return path.read_text(encoding="utf-8")
except FileNotFoundError as exc:
raise ChangelogError(f"changelog not found: {path}") from exc
def write_text(path: Path, text: str) -> None:
path.write_text(text, encoding="utf-8")
def cmd_prepare(args: argparse.Namespace) -> int:
path = Path(args.path)
original = load_text(path)
updated = prepare_release(original, args.version, args.date)
write_text(path, updated)
return 0
def cmd_extract(args: argparse.Namespace) -> int:
path = Path(args.path)
body = extract_section_body(load_text(path), args.version)
if args.output:
write_text(Path(args.output), body)
else:
sys.stdout.write(body)
return 0
def build_parser() -> argparse.ArgumentParser:
parser = argparse.ArgumentParser(description="Prepare and extract changelog release notes")
subparsers = parser.add_subparsers(dest="command", required=True)
prepare = subparsers.add_parser("prepare", help="Move Unreleased into a versioned section")
prepare.add_argument("--path", default="CHANGELOG.md")
prepare.add_argument("--version", required=True)
prepare.add_argument("--date", default=str(date.today()))
prepare.set_defaults(func=cmd_prepare)
extract = subparsers.add_parser("extract", help="Extract a version section body")
extract.add_argument("--path", default="CHANGELOG.md")
extract.add_argument("--version", required=True)
extract.add_argument("--output")
extract.set_defaults(func=cmd_extract)
return parser
def main() -> int:
parser = build_parser()
args = parser.parse_args()
try:
return args.func(args)
except ChangelogError as exc:
print(f"error: {exc}", file=sys.stderr)
return 1
if __name__ == "__main__":
raise SystemExit(main())