Continue GC code review: Pydantic

tests/api/test_v4_documents.py

@@ -117,6 +117,25 @@ def test_set_document_type_by_code_updates_canonical_fields(tmp_path):
     assert payload["document_type_code"] == "record"
 
 
+def test_document_type_payload_requires_exactly_one_selector(tmp_path):
+    with _v4_api_client(tmp_path, db_filename="api-doc-type-validation.db") as (client, db_url):
+        document_id, _ = _seed_document_and_person(db_url=db_url)
+
+        missing = client.put(f"/api/v4/documents/{document_id}/type", json={})
+        conflicting = client.put(
+            f"/api/v4/documents/{document_id}/type",
+            json={"document_type_id": str(UUID(int=1)), "document_type_code": "record"},
+        )
+        unexpected = client.put(
+            f"/api/v4/documents/{document_id}/type",
+            json={"document_type_code": "record", "ignored": True},
+        )
+
+    assert missing.status_code == 422
+    assert conflicting.status_code == 422
+    assert unexpected.status_code == 422
+
+
 def test_document_people_role_aware_write_read_and_delete(tmp_path):
     with _v4_api_client(tmp_path, db_filename="api-links.db") as (client, db_url):
         document_id, person_id = _seed_document_and_person(db_url=db_url)
@@ -155,6 +174,19 @@ def test_document_people_role_aware_write_read_and_delete(tmp_path):
         assert list_after_delete.json()["links"] == []
 
 
+def test_document_person_link_defaults_to_author_when_role_is_omitted(tmp_path):
+    with _v4_api_client(tmp_path, db_filename="api-default-role.db") as (client, db_url):
+        document_id, person_id = _seed_document_and_person(db_url=db_url)
+
+        response = client.post(
+            f"/api/v4/documents/{document_id}/people",
+            json={"person_id": str(person_id)},
+        )
+
+    assert response.status_code == 200
+    assert response.json()["role_code"] == "author"
+
+
 def test_duplicate_document_person_link_returns_conflict_envelope(tmp_path):
     with _v4_api_client(tmp_path, db_filename="api-dup.db") as (client, db_url):
         document_id, person_id = _seed_document_and_person(db_url=db_url)