fix(managed): make Claude plugin cleanup symlink-safe

Author: gauss-math-inc

gauss_cli/autoformalize.py

@@ -881,18 +881,23 @@ def _ensure_claude_user_plugin_state(
 
 
 def _replace_tree_link(destination: Path, source: Path) -> None:
-    if destination.exists() or destination.is_symlink():
-        if destination.is_symlink() or destination.is_file():
-            destination.unlink()
-        else:
-            shutil.rmtree(destination)
+    _remove_existing_path(destination)
     destination.parent.mkdir(parents=True, exist_ok=True)
     try:
         destination.symlink_to(source, target_is_directory=source.is_dir())
     except OSError:
         shutil.copytree(source, destination, symlinks=True)
 
 
+def _remove_existing_path(path: Path) -> None:
+    if not path.exists() and not path.is_symlink():
+        return
+    if path.is_symlink() or path.is_file():
+        path.unlink()
+        return
+    shutil.rmtree(path)
+
+
 def _sync_prewarmed_claude_plugin(
     *,
     real_home: Path,
@@ -1489,8 +1494,7 @@ def _ensure_git_checkout(
             error_prefix="Failed to check out the managed asset revision",
         )
     else:
-        if destination.exists():
-            shutil.rmtree(destination)
+        _remove_existing_path(destination)
         destination.parent.mkdir(parents=True, exist_ok=True)
         if revision:
             _run(
@@ -1548,8 +1552,7 @@ def _stage_tree(*, source: Path, destination: Path, revision: str) -> None:
     if revision_file.exists() and revision_file.read_text(encoding="utf-8").strip() == revision:
         return
 
-    if destination.exists():
-        shutil.rmtree(destination)
+    _remove_existing_path(destination)
     shutil.copytree(source, destination)
     revision_file.write_text(f"{revision}\n", encoding="utf-8")
 
@@ -1683,8 +1686,7 @@ def _install_managed_claude_plugin(
     plugin_id = f"{plugin_name}@{marketplace_name}"
 
     plugin_state_root = backend_home / ".claude" / "plugins"
-    if plugin_state_root.exists():
-        shutil.rmtree(plugin_state_root)
+    _remove_existing_path(plugin_state_root)
 
     cli_env = dict(base_environment)
     cli_env["HOME"] = str(backend_home)

tests/gauss_cli/test_autoformalize.py

@@ -217,6 +217,57 @@ def fake_run(argv, *, error_prefix, env=None, cwd=None):
     assert calls[0][1]["HOME"] == str(backend_home)
 
 
+def test_install_managed_claude_plugin_replaces_symlinked_plugin_state(monkeypatch, tmp_path: Path):
+    backend_home = tmp_path / "claude-home"
+    marketplace_source = tmp_path / "lean4-skills"
+    plugin_source = marketplace_source / "plugins" / "lean4"
+    install_path = backend_home / ".claude" / "plugins" / "cache" / "lean4-skills" / "lean4" / "4.4.0"
+    legacy_plugins_root = tmp_path / "legacy-plugins"
+    (marketplace_source / ".claude-plugin").mkdir(parents=True)
+    (plugin_source / ".claude-plugin").mkdir(parents=True)
+    (marketplace_source / ".claude-plugin" / "marketplace.json").write_text(
+        json.dumps({"name": "lean4-skills"}),
+        encoding="utf-8",
+    )
+    (plugin_source / ".claude-plugin" / "plugin.json").write_text(
+        json.dumps({"name": "lean4", "version": "4.4.0"}),
+        encoding="utf-8",
+    )
+    legacy_plugins_root.mkdir(parents=True)
+    plugin_state_root = backend_home / ".claude" / "plugins"
+    plugin_state_root.parent.mkdir(parents=True, exist_ok=True)
+    plugin_state_root.symlink_to(legacy_plugins_root, target_is_directory=True)
+
+    def fake_run(argv, *, error_prefix, env=None, cwd=None):
+        stdout = ""
+        if list(argv)[1:3] == ["plugin", "install"]:
+            install_path.mkdir(parents=True, exist_ok=True)
+        if list(argv)[-2:] == ["list", "--json"]:
+            stdout = json.dumps(
+                [
+                    {
+                        "id": "lean4@lean4-skills",
+                        "installPath": str(install_path),
+                    }
+                ]
+            )
+        return SimpleNamespace(stdout=stdout)
+
+    monkeypatch.setattr(autoformalize, "_run", fake_run)
+
+    result = autoformalize._install_managed_claude_plugin(
+        claude_executable="/usr/bin/claude",
+        backend_home=backend_home,
+        base_environment={"PATH": "/usr/bin"},
+        marketplace_source=marketplace_source,
+        plugin_source=plugin_source,
+    )
+
+    assert result == install_path.resolve()
+    assert not plugin_state_root.is_symlink()
+    assert install_path.exists()
+
+
 def test_resolve_uv_runner_uses_default_user_scoped_package(monkeypatch):
     monkeypatch.setattr(
         autoformalize.shutil,