fix: compute consistent nodeids for paths outside rootpath

Fix conftest fixture scoping when testpaths points outside rootdir (#14004).

Previously, conftests outside rootpath got nodeid '' (empty string),
making their fixtures global and leaking to sibling directories.

Changes:
- Remove initial_paths from compute_nodeid_prefix_for_path since nodeids
  relate to collection tree structure, not command-line paths
- Use compute_nodeid_prefix_for_path in pytest_plugin_registered for
  consistent conftest baseid computation
- Paths outside rootpath now consistently use bestrelpath from invocation_dir

This ensures conftest fixtures are properly scoped regardless of whether
tests are inside or outside rootpath.

Co-authored-by: Cursor AI <ai@cursor.sh>
Co-authored-by: Anthropic Claude Opus 4 <claude@anthropic.com>

Author: 3 people

src/_pytest/fixtures.py

@@ -1629,14 +1629,13 @@ def pytest_plugin_registered(self, plugin: _PluggyPlugin, plugin_name: str) -> N
             # case-insensitive systems (Windows) and other normalization issues
             # (issue #11816).
             conftestpath = absolutepath(plugin_name)
-            try:
-                nodeid = str(conftestpath.parent.relative_to(self.config.rootpath))
-            except ValueError:
-                nodeid = ""
-            if nodeid == ".":
-                nodeid = ""
-            if os.sep != nodes.SEP:
-                nodeid = nodeid.replace(os.sep, nodes.SEP)
+            # initial_paths not available yet at plugin registration time,
+            # so we skip that step and fall back to bestrelpath
+            nodeid = nodes.compute_nodeid_prefix_for_path(
+                path=conftestpath.parent,
+                rootpath=self.config.rootpath,
+                invocation_dir=self.config.invocation_params.dir,
+            )
         else:
             nodeid = None
 

src/_pytest/nodes.py

@@ -622,22 +622,19 @@ def compute_nodeid_prefix_for_path(
     path: Path,
     rootpath: Path,
     invocation_dir: Path,
-    initial_paths: frozenset[Path],
     site_packages: frozenset[Path] | None = None,
 ) -> str:
     """Compute a nodeid prefix for a filesystem path.
 
     The nodeid prefix is computed based on the path's relationship to:
     1. rootpath - if relative, use simple relative path
-    2. initial_paths - if relative to an initial path, use that
-    3. site-packages - use "site://<package>/<path>" prefix
-    4. invocation_dir - if close by, use relative path with ".." components
-    5. Otherwise, use absolute path
+    2. site-packages - use "site://<package>/<path>" prefix
+    3. invocation_dir - if close by, use relative path with ".." components
+    4. Otherwise, use absolute path
 
     :param path: The path to compute a nodeid prefix for.
     :param rootpath: The pytest root path.
     :param invocation_dir: The directory from which pytest was invoked.
-    :param initial_paths: The initial paths (testpaths or command line args).
     :param site_packages: Optional set of site-packages directories. If None,
         uses the cached system site-packages directories.
 
@@ -653,19 +650,14 @@ def compute_nodeid_prefix_for_path(
     except ValueError:
         pass
 
-    # 2. Try relative to initial_paths
-    nodeid = _check_initialpaths_for_relpath(initial_paths, path)
-    if nodeid is not None:
-        return nodeid.replace(os.sep, SEP) if nodeid else ""
-
-    # 3. Check if path is in site-packages
+    # 2. Check if path is in site-packages
     site_info = _path_in_site_packages(path, site_packages)
     if site_info is not None:
         _sp_dir, rel_path = site_info
         result = f"site://{rel_path}"
         return result.replace(os.sep, SEP)
 
-    # 4. Try relative to invocation_dir if "close by" (i.e., not too many ".." components)
+    # 3. Try relative to invocation_dir if "close by" (i.e., not too many ".." components)
     rel_from_invocation = bestrelpath(invocation_dir, path)
     # Count the number of ".." components - if it's reasonable, use the relative path
     # Also check total path length to avoid overly long relative paths
@@ -677,7 +669,7 @@ def compute_nodeid_prefix_for_path(
     if up_count <= 2 and rel_from_invocation != str(path):
         return rel_from_invocation.replace(os.sep, SEP)
 
-    # 5. Fall back to absolute path
+    # 4. Fall back to absolute path
     return str(path).replace(os.sep, SEP)
 
 
@@ -725,7 +717,6 @@ def __init__(
                 path=path,
                 rootpath=session.config.rootpath,
                 invocation_dir=session.config.invocation_params.dir,
-                initial_paths=session._initialpaths,
             )
 
         super().__init__(

testing/test_nodes.py

@@ -184,14 +184,13 @@ def test_compute_nodeid_inside_rootpath(self, tmp_path: Path) -> None:
             path=test_file,
             rootpath=rootpath,
             invocation_dir=rootpath,
-            initial_paths=frozenset(),
             site_packages=frozenset(),
         )
 
         assert result == "tests/test_foo.py"
 
-    def test_compute_nodeid_in_initial_paths(self, tmp_path: Path) -> None:
-        """Test nodeid computation for paths relative to initial_paths."""
+    def test_compute_nodeid_outside_rootpath(self, tmp_path: Path) -> None:
+        """Test nodeid computation for paths outside rootpath uses bestrelpath."""
         rootpath = tmp_path / "project"
         rootpath.mkdir()
         tests_dir = tmp_path / "tests"
@@ -203,11 +202,11 @@ def test_compute_nodeid_in_initial_paths(self, tmp_path: Path) -> None:
             path=test_file,
             rootpath=rootpath,
             invocation_dir=rootpath,
-            initial_paths=frozenset([tests_dir]),
             site_packages=frozenset(),
         )
 
-        assert result == "test_foo.py"
+        # Uses bestrelpath since outside rootpath
+        assert result == "../tests/test_foo.py"
 
     def test_compute_nodeid_in_site_packages(self, tmp_path: Path) -> None:
         """Test nodeid computation for paths in site-packages uses site:// prefix."""
@@ -223,7 +222,6 @@ def test_compute_nodeid_in_site_packages(self, tmp_path: Path) -> None:
             path=pkg_test,
             rootpath=rootpath,
             invocation_dir=rootpath,
-            initial_paths=frozenset(),
             site_packages=frozenset([fake_site_packages]),
         )
 
@@ -241,8 +239,6 @@ def test_compute_nodeid_nearby_relative(self, tmp_path: Path) -> None:
             path=sibling,
             rootpath=rootpath,
             invocation_dir=rootpath,
-            initial_paths=frozenset(),
-            site_packages=frozenset(),
         )
 
         assert result == "../sibling/tests/test_foo.py"
@@ -259,8 +255,6 @@ def test_compute_nodeid_far_away_absolute(self, tmp_path: Path) -> None:
             path=far_away,
             rootpath=rootpath,
             invocation_dir=rootpath,
-            initial_paths=frozenset(),
-            site_packages=frozenset(),
         )
 
         # Should use absolute path since it's more than 2 levels up
@@ -275,25 +269,6 @@ def test_compute_nodeid_rootpath_itself(self, tmp_path: Path) -> None:
             path=rootpath,
             rootpath=rootpath,
             invocation_dir=rootpath,
-            initial_paths=frozenset(),
-            site_packages=frozenset(),
-        )
-
-        assert result == ""
-
-    def test_compute_nodeid_initial_path_itself(self, tmp_path: Path) -> None:
-        """Test nodeid computation for initial_path itself returns empty string."""
-        rootpath = tmp_path / "project"
-        rootpath.mkdir()
-        tests_dir = tmp_path / "tests"
-        tests_dir.mkdir()
-
-        result = nodes.compute_nodeid_prefix_for_path(
-            path=tests_dir,
-            rootpath=rootpath,
-            invocation_dir=rootpath,
-            initial_paths=frozenset([tests_dir]),
-            site_packages=frozenset(),
         )
 
         assert result == ""