update skills

.agents/skills/git-guardrails-claude-code/scripts/block-dangerous-git.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+
+if ! command -v python3 >/dev/null 2>&1; then
+  printf '%s\n' 'BLOCKED: Python 3 is required to inspect this command.' >&2
+  exit 2
+fi
+
+exec python3 -c '
+import itertools
+import json
+import shlex
+import sys
+
+def block(reason):
+    print("BLOCKED: " + reason, file=sys.stderr)
+    sys.exit(2)
+
+try:
+    command = json.load(sys.stdin)["tool_input"]["command"]
+    if not isinstance(command, str) or not command.strip():
+        raise ValueError("missing command")
+    lexer = shlex.shlex(command.replace("\\\n", ""), posix=True, punctuation_chars=";&|()\n")
+    lexer.whitespace = " \t\r"
+    lexer.whitespace_split = True
+    tokens = list(lexer)
+except (ValueError, KeyError, TypeError):
+    block("Cannot parse the command input.")
+
+value_options = {"-C", "-c", "--git-dir", "--work-tree", "--namespace", "--config-env"}
+flag_options = {"-p", "--paginate", "-P", "--no-pager", "--bare", "--literal-pathspecs"}
+# ponytail: conservative token inspection; shell expansion and aliases require sandbox enforcement.
+for separator, group in itertools.groupby(tokens, lambda token: bool(token) and token[0] in ";&|()\n"):
+    if separator:
+        continue
+    words = list(group)
+    for index, word in enumerate(words):
+        if word.rsplit("/", 1)[-1] != "git":
+            continue
+        args = words[index + 1:]
+        while args and args[0].startswith("-"):
+            option = args.pop(0)
+            if option in value_options:
+                if not args:
+                    block("Missing Git option value.")
+                args.pop(0)
+            elif option in flag_options or option.split("=", 1)[0] in value_options:
+                continue
+            else:
+                block("Unsupported Git option; inspect this command manually.")
+        if not args:
+            continue
+        operation, *args = args
+        short_flags = "".join(arg[1:] for arg in args if arg.startswith("-") and not arg.startswith("--"))
+        force = "--force" in args or "f" in short_flags
+        dangerous = (
+            operation == "push"
+            or operation == "reset" and "--hard" in args
+            or operation == "clean" and force
+            or operation == "branch" and ("D" in short_flags or force and ("d" in short_flags or "--delete" in args))
+            or operation in {"checkout", "restore"} and "." in args
+        )
+        if dangerous:
+            block("Git " + operation + " is disabled by this hook.")
+'

.agents/skills/git-guardrails-claude-code/scripts/test_guardrail.py

@@ -0,0 +1,61 @@
+"""Run with python3; command payloads are inspected, never executed."""
+
+import json
+import os
+from pathlib import Path
+import subprocess
+
+
+hook = Path(__file__).with_name("block-dangerous-git.sh")
+
+
+def check(payload, expected, env=None):
+    result = subprocess.run(
+        ["/bin/bash", str(hook)], input=payload, text=True, capture_output=True, env=env
+    )
+    assert result.returncode == expected, (payload, result.returncode, result.stderr)
+    if expected == 2:
+        assert result.stderr.startswith("BLOCKED:"), result.stderr
+
+
+for command in (
+    "git push origin main",
+    "git push --force-with-lease origin main",
+    "git -C /tmp/example push origin main",
+    "git -c core.pager=cat --no-pager push",
+    "git --git-dir=/tmp/example push",
+    "git  push",
+    "git status;git push",
+    "git status\ngit push",
+    "git \\\npush origin main",
+    "git pu\\\nsh origin main",
+    "git reset --ha\\\nrd HEAD",
+    "git reset --hard HEAD",
+    "git clean -xdf",
+    "git clean --force",
+    "git branch -D topic",
+    "git branch -df topic",
+    "git branch -vD topic",
+    "git branch --delete --force topic",
+    "git checkout -- .",
+    "git restore .",
+):
+    check(json.dumps({"tool_input": {"command": command}}), 2)
+
+for command in (
+    "git status",
+    "git diff",
+    "git -C /tmp/example status",
+    "git branch -d merged-topic",
+    "git reset --soft HEAD~1",
+    "echo 'git push origin main'",
+    'echo ""',
+    "git reset --soft HEAD; echo --hard",
+):
+    check(json.dumps({"tool_input": {"command": command}}), 0)
+
+for payload in ("", "{", "{}", "[]", '{"tool_input":{"command":null}}'):
+    check(payload, 2)
+check('{"tool_input":{"command":"git status"}}', 2, {**os.environ, "PATH": ""})
+check('{"tool_input":{"command":"git \\\""}}', 2)
+print("Guardrail checks passed")