fix(python): sync fail-closed Cursor hooks

sdks/python/tests/test_cursor_security.py

@@ -0,0 +1,250 @@
+from __future__ import annotations
+
+import json
+import os
+from pathlib import Path
+
+import pytest
+
+from cursor_support import (
+    AGENT_ID,
+    prepare_fixture,
+    symlink_or_skip,
+    write_json,
+    write_text,
+)
+
+
+@pytest.mark.parametrize(
+    "runtime_name",
+    [
+        "guard.py",
+        "hook.py",
+        "private.key",
+        "chain-state.json",
+        "status-cache.json",
+        "error.log",
+    ],
+)
+def test_orphan_runtime_artifacts_are_rejected(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+    runtime_name: str,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    artifact = fixture.agent_dir / runtime_name
+    write_text(artifact, "orphan\n")
+
+    with pytest.raises(ValueError, match="identity cannot be verified"):
+        fixture.install()
+
+    assert artifact.read_text(encoding="utf-8") == "orphan\n"
+    assert fixture.config_path.exists() is False
+
+
+def test_mismatched_runtime_identity_is_rejected_before_writes(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    write_json(
+        fixture.runtime_config_path,
+        {"agent_id": "another-agent", "agent_name": "cursor"},
+    )
+    original = fixture.runtime_config_path.read_text(encoding="utf-8")
+
+    with pytest.raises(ValueError, match="identity does not match"):
+        fixture.install()
+
+    assert fixture.runtime_config_path.read_text(encoding="utf-8") == original
+    assert fixture.config_path.exists() is False
+
+
+@pytest.mark.parametrize(
+    "runtime_name",
+    [
+        "config.json",
+        "private.key",
+        "guard.py",
+        "hook.py",
+        "chain-state.json",
+        "status-cache.json",
+        "error.log",
+    ],
+)
+def test_symbolic_link_runtime_is_rejected_before_config_writes(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+    runtime_name: str,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    target = fixture.home_dir / f"{runtime_name}.target"
+    source = (
+        json.dumps({"agent_id": AGENT_ID, "agent_name": "cursor"})
+        if runtime_name == "config.json"
+        else "target\n"
+    )
+    write_text(target, source)
+    runtime_path = fixture.agent_dir / runtime_name
+    symlink_or_skip(target, runtime_path)
+
+    with pytest.raises(OSError, match="physical file"):
+        fixture.install()
+
+    assert target.read_text(encoding="utf-8") == source
+    assert fixture.config_path.exists() is False
+
+
+def test_symbolic_link_config_is_rejected_and_target_is_preserved(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    target = fixture.home_dir / "cursor-hooks.target.json"
+    original = '{"version":1,"hooks":{}}\n'
+    write_text(target, original)
+    fixture.config_path.parent.mkdir(parents=True)
+    symlink_or_skip(target, fixture.config_path)
+
+    with pytest.raises(OSError, match="physical file"):
+        fixture.install()
+
+    assert target.read_text(encoding="utf-8") == original
+    assert fixture.config_path.is_symlink()
+
+
+def test_symbolic_link_config_directory_is_rejected(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    target = fixture.home_dir / "cursor-target"
+    target.mkdir()
+    symlink_or_skip(target, fixture.config_path.parent, directory=True)
+
+    with pytest.raises(OSError, match="not a physical directory"):
+        fixture.install()
+
+    assert list(target.iterdir()) == []
+
+
+def test_symbolic_link_agent_directory_is_rejected(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    fixture.agent_dir.rmdir()
+    target = fixture.home_dir / "agent-target"
+    target.mkdir()
+    symlink_or_skip(target, fixture.agent_dir, directory=True)
+
+    with pytest.raises(OSError, match="not a physical directory"):
+        fixture.install()
+
+    assert fixture.config_path.exists() is False
+    assert list(target.iterdir()) == []
+
+
+def test_symbolic_link_runtime_root_is_rejected(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    fixture.agent_dir.rmdir()
+    fixture.agent_dir.parent.rmdir()
+    target = fixture.home_dir / "runtime-target"
+    (target / AGENT_ID).mkdir(parents=True)
+    symlink_or_skip(target, fixture.agent_dir.parent, directory=True)
+
+    with pytest.raises(OSError, match="not a physical directory"):
+        fixture.install()
+
+    assert fixture.config_path.exists() is False
+    assert list((target / AGENT_ID).iterdir()) == []
+
+
+@pytest.mark.parametrize(
+    "runtime_name",
+    ["config.json", "private.key", "guard.py", "hook.py"],
+)
+def test_status_rejects_symbolic_link_runtime_files(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+    runtime_name: str,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    fixture.install()
+    runtime_path = fixture.agent_dir / runtime_name
+    target = fixture.home_dir / f"status-{runtime_name}.target"
+    target.write_bytes(runtime_path.read_bytes())
+    runtime_path.unlink()
+    symlink_or_skip(target, runtime_path)
+
+    with pytest.raises(OSError, match="physical file"):
+        fixture.plugin.status()
+
+
+def test_transaction_rolls_back_all_files_when_config_commit_fails(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(
+        monkeypatch,
+        tmp_path,
+        existing_config={"version": 1, "hooks": {"sessionStart": []}},
+    )
+    original = fixture.config_path.read_text(encoding="utf-8")
+    real_replace = os.replace
+    failed = False
+
+    def fail_config_once(source: str, destination: str) -> None:
+        nonlocal failed
+        if os.path.abspath(destination) == str(fixture.config_path) and not failed:
+            failed = True
+            raise OSError("injected config commit failure")
+        real_replace(source, destination)
+
+    monkeypatch.setattr(os, "replace", fail_config_once)
+
+    with pytest.raises(OSError, match="injected config commit failure"):
+        fixture.install()
+
+    assert fixture.config_path.read_text(encoding="utf-8") == original
+    for path in (
+        fixture.guard_path,
+        fixture.hook_path,
+        fixture.runtime_config_path,
+        fixture.private_key_path,
+    ):
+        assert path.exists() is False
+    assert not list(fixture.home_dir.rglob("*.tmp"))
+    assert not list(fixture.home_dir.rglob("*.rollback"))
+
+
+def test_transaction_detects_concurrent_config_change(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    from elydora.plugins._transaction import write_changes
+    from elydora.plugins.cursor_contract import render_document
+    from elydora.plugins.cursor_io import read_document, rendered_change
+
+    fixture = prepare_fixture(
+        monkeypatch,
+        tmp_path,
+        existing_config={
+            "version": 1,
+            "hooks": {"sessionStart": [{"command": "original"}]},
+        },
+    )
+    document = read_document()
+    change = rendered_change(render_document(document, {}))
+    assert change is not None
+    concurrent = '{"version":1,"hooks":{"sessionStart":[]}}\n'
+    fixture.config_path.write_text(concurrent, encoding="utf-8")
+
+    with pytest.raises(OSError, match="changed during installation"):
+        write_changes([change], "Update Cursor hooks")
+
+    assert fixture.config_path.read_text(encoding="utf-8") == concurrent
+    assert not list(fixture.config_path.parent.glob("*.tmp"))