feat(cli): add code-scanning command to download GitHub scan results

pkgmgr code-scanning fetches a repository's GitHub code scanning alerts (and analysis metadata) via the gh CLI and writes alerts.json, a readable summary.md digest, and analyses.json into a timestamped directory (default /tmp/<repo>/code-scanner/<YYYYMMDDHHMMSS>) for offline analysis. The repository is resolved from gh or --repo; authentication is delegated to gh; --state filters by alert state.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/pkgmgr/actions/code_scanning/__init__.py

@@ -0,0 +1,161 @@
+"""Download GitHub code scanning results via the ``gh`` CLI.
+
+Fetches all code scanning alerts (and the analysis metadata) for a
+repository and writes them, plus a readable digest, into a timestamped
+directory so they can be read and analysed offline. Authentication is
+delegated to ``gh`` (credentials from its keyring/login).
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import subprocess
+from collections import Counter
+from dataclasses import dataclass, field
+from datetime import datetime
+from typing import Any, List, Optional
+
+
+class CodeScanningError(RuntimeError):
+    """Raised when code scanning results cannot be downloaded."""
+
+
+@dataclass
+class CodeScanningResult:
+    repo: str
+    output_dir: str
+    alert_count: int
+    files: List[str] = field(default_factory=list)
+
+
+def _gh(args: List[str]) -> "subprocess.CompletedProcess[str]":
+    return subprocess.run(["gh", *args], capture_output=True, text=True)
+
+
+def _resolve_repo(repo: Optional[str]) -> str:
+    if repo:
+        return repo
+    proc = _gh(["repo", "view", "--json", "nameWithOwner", "-q", ".nameWithOwner"])
+    name = proc.stdout.strip()
+    if proc.returncode != 0 or not name:
+        raise CodeScanningError(
+            "could not resolve the current repository; run inside a GitHub "
+            "repo or pass --repo OWNER/REPO "
+            f"({proc.stderr.strip()})"
+        )
+    return name
+
+
+def _fetch_json(endpoint: str, params: Optional[List[str]] = None) -> Any:
+    args = ["api", endpoint, "--paginate"]
+    for param in params or []:
+        args += ["-f", param]
+    proc = _gh(args)
+    if proc.returncode != 0:
+        raise CodeScanningError(
+            f"gh api {endpoint} failed: {proc.stderr.strip() or 'unknown error'}"
+        )
+    body = proc.stdout.strip()
+    return json.loads(body) if body else []
+
+
+def _alert_row(alert: dict) -> str:
+    rule = alert.get("rule") or {}
+    instance = alert.get("most_recent_instance") or {}
+    location = instance.get("location") or {}
+    message = (instance.get("message") or {}).get("text", "").strip().replace("\n", " ")
+    severity = rule.get("security_severity_level") or rule.get("severity") or "unknown"
+    path = location.get("path", "?")
+    line = location.get("start_line", "?")
+    state = alert.get("state", "?")
+    rule_id = rule.get("id", "?")
+    return f"- [{severity}] {rule_id} — {path}:{line} ({state})\n  {message}"
+
+
+def _build_summary(repo: str, generated_at: str, alerts: List[dict]) -> str:
+    by_severity: Counter = Counter()
+    by_state: Counter = Counter()
+    by_rule: Counter = Counter()
+    for alert in alerts:
+        rule = alert.get("rule") or {}
+        by_severity[
+            rule.get("security_severity_level") or rule.get("severity") or "unknown"
+        ] += 1
+        by_state[alert.get("state", "unknown")] += 1
+        by_rule[rule.get("id", "unknown")] += 1
+
+    lines = [
+        f"# Code scanning summary — {repo}",
+        "",
+        f"- Generated: {generated_at}",
+        f"- Total alerts: {len(alerts)}",
+        "",
+        "## By severity",
+        "",
+    ]
+    lines += [f"- {sev}: {count}" for sev, count in by_severity.most_common()] or [
+        "- none"
+    ]
+    lines += ["", "## By state", ""]
+    lines += [f"- {state}: {count}" for state, count in by_state.most_common()] or [
+        "- none"
+    ]
+    lines += ["", "## By rule", ""]
+    lines += [f"- {rule}: {count}" for rule, count in by_rule.most_common()] or [
+        "- none"
+    ]
+    lines += ["", "## Alerts", ""]
+    lines += [_alert_row(alert) for alert in alerts] or ["- none"]
+    return "\n".join(lines) + "\n"
+
+
+def download_code_scanning(
+    repo: Optional[str] = None,
+    output_dir: Optional[str] = None,
+    state: Optional[str] = None,
+) -> CodeScanningResult:
+    if not shutil.which("gh"):
+        raise CodeScanningError("the GitHub CLI 'gh' is not installed or not on PATH")
+
+    repo = _resolve_repo(repo)
+    repo_name = repo.rstrip("/").split("/")[-1]
+
+    if output_dir is None:
+        timestamp = datetime.now().strftime("%Y%m%d%H%M%S")
+        output_dir = os.path.join("/tmp", repo_name, "code-scanner", timestamp)
+    output_dir = os.path.abspath(os.path.expanduser(output_dir))
+    os.makedirs(output_dir, exist_ok=True)
+    generated_at = datetime.now().isoformat(timespec="seconds")
+
+    alerts = _fetch_json(
+        f"repos/{repo}/code-scanning/alerts",
+        params=[f"state={state}"] if state else None,
+    )
+
+    files: List[str] = []
+
+    def _write(name: str, content: str) -> None:
+        path = os.path.join(output_dir, name)
+        with open(path, "w", encoding="utf-8") as handle:
+            handle.write(content)
+        files.append(path)
+
+    _write("alerts.json", json.dumps(alerts, indent=2, ensure_ascii=False) + "\n")
+    _write("summary.md", _build_summary(repo, generated_at, alerts))
+
+    try:
+        analyses = _fetch_json(f"repos/{repo}/code-scanning/analyses")
+        _write(
+            "analyses.json", json.dumps(analyses, indent=2, ensure_ascii=False) + "\n"
+        )
+    except CodeScanningError as exc:
+        _write("analyses.json", json.dumps({"error": str(exc)}, indent=2) + "\n")
+
+    return CodeScanningResult(
+        repo=repo,
+        output_dir=output_dir,
+        alert_count=len(alerts),
+        files=files,
+    )

src/pkgmgr/cli/commands/__init__.py

@@ -1,4 +1,5 @@
 from .archive import handle_archive
+from .code_scanning import handle_code_scanning
 from .repos import handle_repos_command
 from .config import handle_config
 from .tools import handle_tools_command
@@ -12,6 +13,7 @@ from .mirror import handle_mirror_command
 
 __all__ = [
     "handle_archive",
+    "handle_code_scanning",
     "handle_repos_command",
     "handle_config",
     "handle_tools_command",

src/pkgmgr/cli/commands/code_scanning.py

@@ -0,0 +1,24 @@
+from __future__ import annotations
+
+import sys
+
+from pkgmgr.actions.code_scanning import CodeScanningError, download_code_scanning
+from pkgmgr.cli.context import CLIContext
+
+
+def handle_code_scanning(args, ctx: CLIContext) -> None:
+    try:
+        result = download_code_scanning(
+            repo=getattr(args, "repo", None),
+            output_dir=getattr(args, "output", None),
+            state=getattr(args, "state", None),
+        )
+    except CodeScanningError as exc:
+        print(f"[ERROR] {exc}", file=sys.stderr)
+        sys.exit(1)
+
+    print(f"[code-scanning] Repository: {result.repo}")
+    print(f"[code-scanning] Alerts:     {result.alert_count}")
+    print(f"[code-scanning] Output:     {result.output_dir}")
+    for path in result.files:
+        print(f"  - {path}")

src/pkgmgr/cli/dispatch.py

@@ -11,6 +11,7 @@ from pkgmgr.core.repository.dir import get_repo_dir
 
 from pkgmgr.cli.commands import (
     handle_archive,
+    handle_code_scanning,
     handle_repos_command,
     handle_tools_command,
     handle_release,
@@ -65,6 +66,10 @@ def dispatch_command(args, ctx: CLIContext) -> None:
         handle_archive(args, ctx)
         return
 
+    if args.command == "code-scanning":
+        handle_code_scanning(args, ctx)
+        return
+
     commands_with_selection = {
         "install",
         "update",

src/pkgmgr/cli/parser/__init__.py

@@ -7,6 +7,7 @@ from pkgmgr.cli.proxy import register_proxy_commands
 from .archive_cmd import add_archive_subparser
 from .branch_cmd import add_branch_subparsers
 from .changelog_cmd import add_changelog_subparser
+from .code_scanning_cmd import add_code_scanning_subparser
 from .common import SortedSubParsersAction
 from .config_cmd import add_config_subparsers
 from .install_update import add_install_update_subparsers
@@ -67,6 +68,7 @@ def create_parser(description_text: str) -> argparse.ArgumentParser:
     add_make_subparsers(subparsers)
     add_mirror_subparsers(subparsers)
     add_archive_subparser(subparsers)
+    add_code_scanning_subparser(subparsers)
 
     register_proxy_commands(subparsers)
     return parser

src/pkgmgr/cli/parser/code_scanning_cmd.py

@@ -0,0 +1,39 @@
+from __future__ import annotations
+
+import argparse
+
+
+def add_code_scanning_subparser(subparsers: argparse._SubParsersAction) -> None:
+    """Register the code-scanning subcommand.
+
+    Downloads a repository's GitHub code scanning alerts (and analysis
+    metadata) into a timestamped directory for offline analysis, using the
+    ``gh`` CLI for authentication.
+    """
+    parser = subparsers.add_parser(
+        "code-scanning",
+        help="Download GitHub code scanning results for offline analysis.",
+        description=(
+            "Fetch all code scanning alerts (plus analysis metadata) for a "
+            "repository via the gh CLI and write them, with a readable "
+            "summary, into a timestamped directory. Defaults to the current "
+            "repository and /tmp/<repo>/code-scanner/<YYYYMMDDHHMMSS>."
+        ),
+    )
+    parser.add_argument(
+        "--repo",
+        default=None,
+        help="Target repository as OWNER/REPO (default: current repo via gh).",
+    )
+    parser.add_argument(
+        "--output",
+        "-o",
+        default=None,
+        help=("Output directory (default: /tmp/<repo>/code-scanner/<YYYYMMDDHHMMSS>)."),
+    )
+    parser.add_argument(
+        "--state",
+        default=None,
+        choices=["open", "closed", "dismissed", "fixed"],
+        help="Only download alerts in this state (default: all states).",
+    )