From 5f456e7916dc0f29f9c434a2393b4c37bad99ed2 Mon Sep 17 00:00:00 2001
From: Sasa Junuzovic <44276455+microsasa@users.noreply.github.com>
Date: Fri, 10 Apr 2026 02:39:41 -0700
Subject: [PATCH] Add test for OSError in _full_scandir_discovery is_dir()

Cover the untested except-OSError branch in _full_scandir_discovery()
(parser.py lines 307-310). When DirEntry.is_dir(follow_symlinks=False)
raises OSError, the entry is correctly treated as a non-directory and
skipped. This test verifies that behavior using a MagicMock DirEntry,
mirroring the existing test_stat_failure_on_entry_skipped pattern in
test_vscode_parser.py.

Closes #896

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 tests/copilot_usage/test_parser.py | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/tests/copilot_usage/test_parser.py b/tests/copilot_usage/test_parser.py
index fdc9682..86d6606 100644
--- a/tests/copilot_usage/test_parser.py
+++ b/tests/copilot_usage/test_parser.py
@@ -55,6 +55,7 @@
     _extract_session_name,
     _first_pass,
     _FirstPassResult,
+    _full_scandir_discovery,
     _infer_model_from_metrics,
     _insert_session_entry,
     _read_config_model,
@@ -522,6 +523,33 @@ def test_two_level_deep_events_not_discovered(self, tmp_path: Path) -> None:
         assert paths == [valid]
 
 
+# ---------------------------------------------------------------------------
+# _full_scandir_discovery — OSError on DirEntry.is_dir (issue #896)
+# ---------------------------------------------------------------------------
+
+
+class TestFullScanDirDiscovery:
+    """Cover error-handling paths in _full_scandir_discovery."""
+
+    def test_is_dir_oserror_entry_is_skipped(self, tmp_path: Path) -> None:
+        """An entry whose is_dir() raises OSError must be silently skipped."""
+        from unittest.mock import MagicMock
+
+        bad_entry = MagicMock(spec=os.DirEntry)
+        bad_entry.name = "broken-session"
+        bad_entry.is_dir.side_effect = OSError("permission denied")
+
+        ctx = MagicMock()
+        ctx.__enter__ = MagicMock(return_value=iter([bad_entry]))
+        ctx.__exit__ = MagicMock(return_value=False)
+
+        with patch("os.scandir", return_value=ctx):
+            result = _full_scandir_discovery(tmp_path, include_plan=False)
+
+        assert result == []
+        bad_entry.is_dir.assert_called_once_with(follow_symlinks=False)
+
+
 # ---------------------------------------------------------------------------
 # _discover_with_identity — no stat for absent plan.md (issue #763)
 # ---------------------------------------------------------------------------