fix(hooks): resolve Claude plugin hook runner cross-platform

.claude-plugin/hooks/mempal-precompact-hook.sh

@@ -1,5 +1,24 @@
 #!/bin/bash
 # MemPalace PreCompact Hook — thin wrapper calling Python CLI
 # All logic lives in mempalace.hooks_cli for cross-harness extensibility
-INPUT=$(cat)
-echo "$INPUT" | python3 -m mempalace hook run --hook precompact --harness claude-code
+run_mempalace_hook() {
+  if command -v mempalace >/dev/null 2>&1; then
+    mempalace hook run "$@"
+    return $?
+  fi
+
+  if command -v python3 >/dev/null 2>&1 && python3 -c "import mempalace" >/dev/null 2>&1; then
+    python3 -m mempalace hook run "$@"
+    return $?
+  fi
+
+  if command -v python >/dev/null 2>&1 && python -c "import mempalace" >/dev/null 2>&1; then
+    python -m mempalace hook run "$@"
+    return $?
+  fi
+
+  echo "MemPalace hook error: could not find a runnable mempalace command or module" >&2
+  return 1
+}
+
+run_mempalace_hook --hook precompact --harness claude-code

.claude-plugin/hooks/mempal-stop-hook.sh

@@ -1,5 +1,24 @@
 #!/bin/bash
 # MemPalace Stop Hook — thin wrapper calling Python CLI
 # All logic lives in mempalace.hooks_cli for cross-harness extensibility
-INPUT=$(cat)
-echo "$INPUT" | python3 -m mempalace hook run --hook stop --harness claude-code
+run_mempalace_hook() {
+  if command -v mempalace >/dev/null 2>&1; then
+    mempalace hook run "$@"
+    return $?
+  fi
+
+  if command -v python3 >/dev/null 2>&1 && python3 -c "import mempalace" >/dev/null 2>&1; then
+    python3 -m mempalace hook run "$@"
+    return $?
+  fi
+
+  if command -v python >/dev/null 2>&1 && python -c "import mempalace" >/dev/null 2>&1; then
+    python -m mempalace hook run "$@"
+    return $?
+  fi
+
+  echo "MemPalace hook error: could not find a runnable mempalace command or module" >&2
+  return 1
+}
+
+run_mempalace_hook --hook stop --harness claude-code

tests/test_claude_plugin_hook_wrappers.py

@@ -0,0 +1,192 @@
+"""Execution tests for Claude plugin hook wrapper scripts."""
+
+import os
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+PLUGIN_HOOKS_DIR = REPO_ROOT / ".claude-plugin" / "hooks"
+BASH = shutil.which("bash")
+
+pytestmark = pytest.mark.skipif(
+    BASH is None,
+    reason="bash required for Claude plugin hook wrapper tests",
+)
+
+SCRIPT_CASES = [
+    ("mempal-stop-hook.sh", "stop"),
+    ("mempal-precompact-hook.sh", "precompact"),
+]
+
+
+def _shell_path(path: Path) -> str:
+    return path.as_posix()
+
+
+def _write_executable(path: Path, content: str) -> None:
+    path.write_text(content, encoding="utf-8")
+    path.chmod(0o755)
+
+
+def _make_bin_dir(tmp_path: Path, executables: dict[str, str]) -> Path:
+    bin_dir = tmp_path / "bin"
+    bin_dir.mkdir()
+    for name, content in executables.items():
+        _write_executable(bin_dir / name, content)
+    return bin_dir
+
+
+def _capture_stdin_to(output_path: Path) -> str:
+    return (
+        'stdin_payload=""\n'
+        'while IFS= read -r line || [ -n "$line" ]; do\n'
+        '  stdin_payload="${stdin_payload}${line}"\n'
+        "done\n"
+        f'printf \'%s\' "$stdin_payload" > "{_shell_path(output_path)}"\n'
+    )
+
+
+def _run_hook(
+    script_name: str,
+    payload: str,
+    bin_dir: Path,
+) -> subprocess.CompletedProcess[str]:
+    assert BASH is not None
+
+    env = os.environ.copy()
+    env["PATH"] = str(bin_dir)
+
+    return subprocess.run(
+        [BASH, _shell_path(PLUGIN_HOOKS_DIR / script_name)],
+        input=payload,
+        text=True,
+        capture_output=True,
+        cwd=REPO_ROOT,
+        env=env,
+    )
+
+
+@pytest.mark.parametrize(("script_name", "hook_name"), SCRIPT_CASES)
+def test_plugin_hook_wrapper_prefers_mempalace_cli(
+    tmp_path: Path, script_name: str, hook_name: str
+) -> None:
+    args_file = tmp_path / "args.txt"
+    stdin_file = tmp_path / "stdin.json"
+
+    bin_dir = _make_bin_dir(
+        tmp_path,
+        {
+            "mempalace": (
+                "#!/bin/sh\n"
+                f'printf \'%s\' "$*" > "{_shell_path(args_file)}"\n'
+                f"{_capture_stdin_to(stdin_file)}"
+                "printf '{}\\n'\n"
+            ),
+            "python": "#!/bin/sh\nexit 99\n",
+            "python3": "#!/bin/sh\nexit 99\n",
+        },
+    )
+
+    payload = '{"session_id":"abc123"}'
+    result = _run_hook(script_name, payload, bin_dir)
+
+    assert result.returncode == 0
+    assert result.stdout == "{}\n"
+    assert (
+        args_file.read_text(encoding="utf-8")
+        == f"hook run --hook {hook_name} --harness claude-code"
+    )
+    assert stdin_file.read_text(encoding="utf-8") == payload
+
+
+@pytest.mark.parametrize(("script_name", "hook_name"), SCRIPT_CASES)
+@pytest.mark.parametrize("python_name", ["python3", "python"])
+def test_plugin_hook_wrapper_falls_back_to_importable_python(
+    tmp_path: Path, script_name: str, hook_name: str, python_name: str
+) -> None:
+    args_file = tmp_path / "args.txt"
+    stdin_file = tmp_path / "stdin.json"
+
+    python_stub = (
+        "#!/bin/sh\n"
+        'if [ "$1" = "-c" ]; then\n'
+        "  exit 0\n"
+        "fi\n"
+        f'printf \'%s\' "$*" > "{_shell_path(args_file)}"\n'
+        f"{_capture_stdin_to(stdin_file)}"
+        "printf '{}\\n'\n"
+    )
+    bin_dir = _make_bin_dir(tmp_path, {python_name: python_stub})
+
+    payload = '{"session_id":"xyz789"}'
+    result = _run_hook(script_name, payload, bin_dir)
+
+    assert result.returncode == 0
+    assert result.stdout == "{}\n"
+    assert (
+        args_file.read_text(encoding="utf-8")
+        == f"-m mempalace hook run --hook {hook_name} --harness claude-code"
+    )
+    assert stdin_file.read_text(encoding="utf-8") == payload
+
+
+@pytest.mark.parametrize(("script_name", "hook_name"), SCRIPT_CASES)
+def test_plugin_hook_wrapper_errors_cleanly_when_no_runner_exists(
+    tmp_path: Path, script_name: str, hook_name: str
+) -> None:
+    bin_dir = _make_bin_dir(tmp_path, {})
+
+    payload = '{"session_id":"no-runner"}'
+    result = _run_hook(script_name, payload, bin_dir)
+
+    assert result.returncode != 0
+    assert result.stdout == ""
+    assert "could not find a runnable mempalace command or module" in result.stderr
+
+
+@pytest.mark.parametrize(("script_name", "hook_name"), SCRIPT_CASES)
+def test_plugin_hook_wrapper_falls_back_to_python_when_python3_cannot_import(
+    tmp_path: Path, script_name: str, hook_name: str
+) -> None:
+    args_file = tmp_path / "args.txt"
+    stdin_file = tmp_path / "stdin.json"
+    bad_python3_used = tmp_path / "bad_python3_used.txt"
+
+    bin_dir = _make_bin_dir(
+        tmp_path,
+        {
+            "python3": (
+                "#!/bin/sh\n"
+                'if [ "$1" = "-c" ]; then\n'
+                "  exit 1\n"
+                "fi\n"
+                f"printf 'used' > \"{_shell_path(bad_python3_used)}\"\n"
+                "echo 'No module named mempalace' >&2\n"
+                "exit 1\n"
+            ),
+            "python": (
+                "#!/bin/sh\n"
+                'if [ "$1" = "-c" ]; then\n'
+                "  exit 0\n"
+                "fi\n"
+                f'printf \'%s\' "$*" > "{_shell_path(args_file)}"\n'
+                f"{_capture_stdin_to(stdin_file)}"
+                "printf '{}\\n'\n"
+            ),
+        },
+    )
+
+    payload = '{"session_id":"fallback"}'
+    result = _run_hook(script_name, payload, bin_dir)
+
+    assert result.returncode == 0
+    assert result.stdout == "{}\n"
+    assert (
+        args_file.read_text(encoding="utf-8")
+        == f"-m mempalace hook run --hook {hook_name} --harness claude-code"
+    )
+    assert stdin_file.read_text(encoding="utf-8") == payload
+    assert not bad_python3_used.exists()