Update the release notes in post release workflow

Author: rvermeulen

.github/workflows/post-release.yml

@@ -46,4 +46,13 @@ jobs:
             --layout scripts/release/release-layout.yml \
             --repo "$GITHUB_REPOSITORY" \
             --github-token "$GITHUB_REPOSITORY:$GITHUB_TOKEN" "github/codeql-coding-standards-release-engineering:$RELEASE_ENGINEERING_TOKEN" \
-            --skip-checks
+            --skip-checks
+
+      - name: Update release notes
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        run: |
+          python scripts/release/update-release-notes.py \
+            --head-sha $HEAD_SHA \
+            --repo "$GITHUB_REPOSITORY" \
+            --github-token "$GITHUB_TOKEN"

scripts/release/requirements.txt

@@ -1,3 +1,4 @@
 semantic-version==2.10.0
 PyGithub==1.59.1
-PyYAML==6.0.1
+PyYAML==6.0.1
+GitPython==3.1.36

scripts/release/update-release-notes.py

@@ -0,0 +1,72 @@
+from __future__ import annotations # This enables postponed evaluation of type annotations. Required for typing.TYPE_CHECKING. See https://peps.python.org/pep-0563/
+from typing import TYPE_CHECKING
+import subprocess
+from pathlib import Path
+
+if TYPE_CHECKING:
+    from argparse import Namespace
+
+def generate_release_notes() -> str:
+    script_path = Path(__file__).parent / "generate_release_notes.py"
+    cp = subprocess.run(["python", str(script_path)], capture_output=True)
+
+    if cp.returncode != 0:
+        raise Exception(f"Error generating release notes: {cp.stderr.decode('utf-8')}")
+
+    return cp.stdout.decode("utf-8")
+
+def main(args: Namespace) -> int:
+    from github import Github, Auth
+    import semantic_version # type: ignore
+    import re
+    import sys
+
+    repo = Github(auth=Auth.Token(args.github_token)).get_repo(args.repo)
+
+    pull_candidates = [pr for pr in repo.get_pulls(state="open") if pr.head.sha == args.head_sha]
+    if len(pull_candidates) != 1:
+        print(f"Error: expected exactly one PR for SHA {args.head_sha}, but found {len(pull_candidates)}", file=sys.stderr)
+        return 1
+    
+    pull_request = pull_candidates[0]
+
+    if pull_request.state != "open":
+        print(f"Error: PR for version {args.version} is not open", file=sys.stderr)
+        return 1
+    
+    rc_branch_regex = r"^rc/(?P<version>.*)$"
+    rc_branch_match = re.match(rc_branch_regex, pull_request.base.ref)
+    if not rc_branch_match:
+        print(f"Error: PR {pull_request.url} is not based on a release candidate branch", file=sys.stderr)
+        return 1
+
+    release_version = rc_branch_match.group("version")
+
+    try:
+        semantic_version.Version.parse(release_version) # type: ignore
+    except ValueError as e:
+        print(f"Error: invalid version {release_version} use by release branch. Reason {e}", file=sys.stderr)
+        return 1
+
+    releases = [release for release in repo.get_releases() if release.title == f"v{release_version}"]
+    if len(releases) != 1:
+        print(f"Error: expected exactly one release with title {args.version}, but found {len(releases)}", file=sys.stderr)
+        return 1
+    release = releases[0]
+
+    release_notes = generate_release_notes()
+
+    release.update_release(name=release.title, message=release_notes, draft=release.draft, prerelease=release.prerelease, tag_name=release.tag_name)
+
+    return 0
+
+if __name__ == '__main__':
+    import argparse
+    from sys import exit
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--head-sha', help="The head SHA of the release PR for which we update it's corresponding release", required=True)
+    parser.add_argument('--repo', help="The owner and repository name. For example, 'octocat/Hello-World'. Used when testing this script on a fork", required=True, default="github/codeql-coding-standards")
+    parser.add_argument('--github-token', help="The GitHub token to use to update the release", required=True)
+    args = parser.parse_args()
+    exit(main(args))