fix: resolve item.path to absolute in pytest_collection_modifyitems

python/tach/pytest_plugin.py

@@ -325,7 +325,9 @@ def pytest_collection_modifyitems(config: Config, items: list[Item]):
     if state is None:
         return
     items_to_remove = [
-        item for item in items if state.handler.should_remove_items(file_path=item.path)
+        item
+        for item in items
+        if state.handler.should_remove_items(file_path=item.path.resolve())
     ]
     state.handler.num_removed_items = len(items_to_remove)
 

python/tests/test_pytest_plugin.py

@@ -1,7 +1,12 @@
 from __future__ import annotations
 
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
 import pytest
 
+from tach.pytest_plugin import pytest_collection_modifyitems
+
 pytest_plugins = ["pytester"]
 
 
@@ -207,6 +212,46 @@ def test_three(self):
         result.stdout.fnmatch_lines(["*Skipped 8 test* (3 file*"])
 
 
+class TestPytestPluginResolveItemPath:
+    """Unit test that item.path is resolved before passing to should_remove_items.
+
+    pytester always provides absolute item.path, so it can't catch this bug.
+    We mock the handler to verify resolve() is called.
+    """
+
+    def test_should_remove_items_receives_resolved_path(self, tmp_path: Path):
+        # Create a real file so resolve() produces an absolute path
+        test_file = tmp_path / "tests" / "test_foo.py"
+        test_file.parent.mkdir()
+        test_file.touch()
+        relative_path = Path("tests/test_foo.py")
+
+        handler = MagicMock()
+        handler.should_remove_items.return_value = True  # pyright: ignore[reportAny]
+        handler.num_removed_items = 0
+
+        state = MagicMock()
+        state.handler = handler
+        state.skip_enabled = False
+
+        config = MagicMock()
+        config.stash.get.return_value = state  # pyright: ignore[reportAny]
+
+        item = MagicMock()
+        item.path = relative_path
+
+        with patch.object(Path, "resolve", return_value=test_file) as mock_resolve:
+            pytest_collection_modifyitems(config, [item])
+            mock_resolve.assert_called_once()
+
+        # The key assertion: should_remove_items must receive the resolved
+        # absolute path, not the relative item.path
+        called_path: Path = handler.should_remove_items.call_args.kwargs["file_path"]  # pyright: ignore[reportAny]
+        assert called_path == test_file, (
+            f"should_remove_items received {called_path}, expected resolved path {test_file}"
+        )
+
+
 class TestPytestPluginDurations:
     def test_shows_estimated_duration_after_caching(
         self, tach_project: pytest.Pytester