Fix: index root document when a new version is consumed

src/documents/signals/handlers.py

@@ -794,6 +794,11 @@ def cleanup_user_deletion(sender, instance: User | Group, **kwargs) -> None:
 def add_to_index(sender, document, **kwargs) -> None:
     from documents.search import get_backend
 
+    # A newly consumed version is not searchable on its own, its content
+    # becomes the effective content of the root document.
+    if document.root_document_id:
+        document = document.root_document
+
     get_backend().add_or_update(
         document,
         effective_content=document.get_effective_content(),

src/documents/tests/search/test_backend.py

@@ -16,6 +16,7 @@ from documents.search._backend import TantivyBackend
 from documents.search._backend import WriteBatch
 from documents.search._backend import get_backend
 from documents.search._backend import reset_backend
+from documents.signals.handlers import add_to_index
 from documents.tests.factories import CorrespondentFactory
 from documents.tests.factories import DocumentFactory
 from documents.tests.factories import DocumentTypeFactory
@@ -1030,6 +1031,85 @@ class TestHighlightHits:
         assert len(hits) == 0
 
 
+class TestVersionIndexing:
+    """
+    GIVEN:
+        - A root document with a consumed version
+    WHEN:
+        - The consumed version is indexed
+    THEN:
+        - The root document's index entry is updated to reflect the consumed version's content
+    """
+
+    def test_consumed_version_updates_root_entry(
+        self,
+        backend: TantivyBackend,
+        mocker: MockerFixture,
+    ) -> None:
+        root = Document.objects.create(
+            title="Statement",
+            content="",
+            checksum="VER1",
+            pk=90,
+        )
+        backend.add_or_update(root, effective_content=root.get_effective_content())
+        version = Document.objects.create(
+            title="Statement",
+            content="unprotected statement text",
+            checksum="VER2",
+            pk=91,
+            root_document=root,
+        )
+        mocker.patch("documents.search.get_backend", return_value=backend)
+
+        add_to_index(sender=None, document=version)
+
+        assert backend.search_ids("unprotected", user=None) == [root.pk]
+
+    def test_consumed_version_replaces_previous_content(
+        self,
+        backend: TantivyBackend,
+        mocker: MockerFixture,
+    ) -> None:
+        root = Document.objects.create(
+            title="Statement",
+            content="stale original text",
+            checksum="VER3",
+            pk=92,
+        )
+        backend.add_or_update(root, effective_content=root.get_effective_content())
+        version = Document.objects.create(
+            title="Statement",
+            content="fresh version text",
+            checksum="VER4",
+            pk=93,
+            root_document=root,
+        )
+        mocker.patch("documents.search.get_backend", return_value=backend)
+
+        add_to_index(sender=None, document=version)
+
+        assert backend.search_ids("fresh", user=None) == [root.pk]
+        assert backend.search_ids("stale", user=None) == []
+
+    def test_consumed_root_document_is_indexed_directly(
+        self,
+        backend: TantivyBackend,
+        mocker: MockerFixture,
+    ) -> None:
+        root = Document.objects.create(
+            title="Standalone",
+            content="standalone document text",
+            checksum="VER5",
+            pk=94,
+        )
+        mocker.patch("documents.search.get_backend", return_value=backend)
+
+        add_to_index(sender=None, document=root)
+
+        assert backend.search_ids("standalone", user=None) == [root.pk]
+
+
 class TestIndexDirectoryGarbageCollection:
     """Regression tests for Tantivy segment files leaking on disk when
     multiple long-lived worker processes (Granian/Celery) take turns writing