feat(release): publish changelog-driven notes

scripts/extract_changelog.py

@@ -0,0 +1,99 @@
+#!/usr/bin/env python3
+"""Extract one validated Keep a Changelog version section."""
+from __future__ import annotations
+
+import argparse
+from datetime import date
+from pathlib import Path
+import re
+import sys
+
+
+class ChangelogError(ValueError):
+    """A release cannot safely use the supplied changelog."""
+
+
+_SEMVER = r"(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)"
+_VERSION_HEADING = re.compile(
+    rf"^## \[(?P<version>{_SEMVER})\] - (?P<date>.+)$", re.MULTILINE
+)
+
+
+def extract_version_section(changelog: str, version: str) -> str:
+    """Return *version*'s changelog section without altering its bytes.
+
+    The section ends immediately before the next level-two heading.  A release
+    cannot use an absent, empty, or malformed version section.
+    """
+    if not re.fullmatch(_SEMVER, version):
+        raise ChangelogError(f"requested version is not bare semver: {version!r}")
+
+    heading = next(
+        (match for match in _VERSION_HEADING.finditer(changelog)
+         if match.group("version") == version),
+        None,
+    )
+    if heading is None:
+        if re.search(rf"^## \[{re.escape(version)}\].*$", changelog, re.MULTILINE):
+            raise ChangelogError(f"version {version} has a malformed heading or date")
+        raise ChangelogError(f"version {version} is missing from the changelog")
+
+    heading_date = heading.group("date")
+    if not re.fullmatch(r"\d{4}-\d{2}-\d{2}", heading_date):
+        raise ChangelogError(f"version {version} has a malformed release date")
+    try:
+        date.fromisoformat(heading_date)
+    except ValueError as error:
+        raise ChangelogError(f"version {version} has a malformed release date") from error
+
+    next_heading = re.search(r"^## ", changelog[heading.end():], re.MULTILINE)
+    section_end = heading.end() + next_heading.start() if next_heading else len(changelog)
+    section = changelog[heading.start():section_end]
+    if not re.search(r"^- \S", section[heading.end() - heading.start():], re.MULTILINE):
+        raise ChangelogError(f"version {version} has an empty changelog section")
+    return section
+
+
+def extract_changelog(path: Path, version: str) -> str:
+    """Read and extract a requested version from a changelog file."""
+    try:
+        return extract_version_section(path.read_text(encoding="utf-8"), version)
+    except OSError as error:
+        raise ChangelogError(f"cannot read changelog {path}: {error.strerror}") from error
+
+
+def assemble_release_body(section: str, footer: str) -> str:
+    """Append standing guidance while preserving the extracted section verbatim."""
+    separator = "\n" if section.endswith("\n") else "\n\n"
+    return f"{section}{separator}{footer}"
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("changelog", type=Path)
+    parser.add_argument("version")
+    parser.add_argument(
+        "--footer",
+        type=Path,
+        help="append this standing release guidance after the extracted section",
+    )
+    args = parser.parse_args(argv)
+    try:
+        section = extract_changelog(args.changelog, args.version)
+        if args.footer:
+            try:
+                footer = args.footer.read_text(encoding="utf-8")
+            except OSError as error:
+                raise ChangelogError(
+                    f"cannot read release footer {args.footer}: {error.strerror}"
+                ) from error
+            section = assemble_release_body(section, footer)
+        sys.stdout.write(section)
+    except ChangelogError as error:
+        print(f"::error::{error}", file=sys.stderr)
+        return 1
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

scripts/release_request.py

@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+"""Describe the Gitea request that creates or resynchronizes a release."""
+from __future__ import annotations
+
+import argparse
+import json
+from pathlib import Path
+import re
+import sys
+from typing import Any
+
+
+_SEMVER = r"(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)"
+
+
+class ReleaseRequestError(ValueError):
+    """A release request could not be prepared safely."""
+
+
+def build_release_request(
+    version: str, body: str, existing_release: dict[str, Any] | None
+) -> dict[str, Any]:
+    """Return the observable POST or PATCH request for a Gitea release."""
+    if not re.fullmatch(_SEMVER, version):
+        raise ReleaseRequestError(f"version is not bare semver: {version!r}")
+    if existing_release is None:
+        return {
+            "method": "POST",
+            "path": "/releases",
+            "payload": {"tag_name": f"v{version}", "name": f"v{version}", "body": body},
+        }
+
+    release_id = existing_release.get("id")
+    if not isinstance(release_id, int):
+        raise ReleaseRequestError("existing release does not contain an integer id")
+    return {
+        "method": "PATCH",
+        "path": f"/releases/{release_id}",
+        "payload": {"body": body},
+    }
+
+
+def _read_json(path: Path) -> dict[str, Any]:
+    try:
+        value = json.loads(path.read_text(encoding="utf-8"))
+    except (OSError, json.JSONDecodeError) as error:
+        raise ReleaseRequestError(f"cannot read existing release {path}: {error}") from error
+    if not isinstance(value, dict):
+        raise ReleaseRequestError("existing release must be a JSON object")
+    return value
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--version", required=True)
+    parser.add_argument("--body-file", type=Path, required=True)
+    parser.add_argument("--existing-release", type=Path)
+    args = parser.parse_args(argv)
+    try:
+        body = args.body_file.read_text(encoding="utf-8")
+        existing = _read_json(args.existing_release) if args.existing_release else None
+        print(json.dumps(build_release_request(args.version, body, existing)))
+    except (OSError, ReleaseRequestError) as error:
+        print(f"::error::{error}", file=sys.stderr)
+        return 1
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())