Clarify pytest_collection_finish occurs after setting session.items (#14088)

Author: Liam-DeVoe

.gitignore

@@ -51,6 +51,7 @@ coverage.xml
 .vscode
 __pycache__/
 .python-version
+.claude/settings.local.json
 
 # generated by pip
 pip-wheel-metadata/

changelog/14088.doc.rst

@@ -0,0 +1 @@
+Clarified that the default :hook:`pytest_collection` hook sets ``session.items`` before it calls :hook:`pytest_collection_finish`, not after.

doc/en/reference/reference.rst

@@ -757,6 +757,7 @@ items, delete or otherwise amend the test items:
     If this hook is implemented in ``conftest.py`` files, it always receives all collected items, not only those
     under the ``conftest.py`` where it is implemented.
 
+.. hook:: pytest_collection_finish
 .. autofunction:: pytest_collection_finish
 
 Test running (runtest) hooks

src/_pytest/hookspec.py

@@ -248,8 +248,8 @@ def pytest_collection(session: Session) -> object | None:
 
       1. ``pytest_deselected(items)`` for any deselected items (may be called multiple times)
 
-    3. ``pytest_collection_finish(session)``
-    4. Set ``session.items`` to the list of collected items
+    3. Set ``session.items`` to the list of collected items
+    4. ``pytest_collection_finish(session)``
     5. Set ``session.testscollected`` to the number of collected items
 
     You can implement this hook to only perform some action before collection,