Fix invalid contributors causing crash

dandiapi/api/models/version.py

@@ -137,7 +137,7 @@ def citation(cls, metadata):
         version = metadata['version']
         # If we can't find any contributors, use this citation format
         citation = f'{name} ({year}). (Version {version}) [Data set]. DANDI archive. {url}'
-        if 'contributor' in metadata and metadata['contributor']:
+        if 'contributor' in metadata and isinstance(metadata['contributor'], list):
             cl = '; '.join(
                 [
                     val['name']

dandiapi/api/tests/test_dandiset.py

@@ -1010,3 +1010,19 @@ def test_dandiset_rest_search_identifier(api_client, draft_version):
 
     assert results[0]['draft_version']['version'] == draft_version.version
     assert results[0]['draft_version']['name'] == draft_version.name
+
+
+@pytest.mark.django_db()
+@pytest.mark.parametrize(
+    'contributors',
+    [None, 'string', 1, [], {}],
+)
+def test_dandiset_contact_person_malformed_contributors(api_client, draft_version, contributors):
+    draft_version.metadata['contributor'] = contributors
+    draft_version.save()
+
+    results = api_client.get(
+        f'/api/dandisets/{draft_version.dandiset.identifier}/',
+    )
+
+    assert results.data['draft_version']['dandiset']['contact_person'] == ''

dandiapi/api/views/serializers.py

@@ -10,11 +10,11 @@
 from dandiapi.search.models import AssetSearch
 
 
-def extract_contact_person(version):
+def extract_contact_person(version: Version) -> str:
     """Extract a version's contact person from its metadata."""
     # TODO: move this logic into dandischema since it is schema-dependant
     contributors = version.metadata.get('contributor')
-    if contributors is not None:
+    if contributors is not None and isinstance(contributors, list):
         for contributor in contributors:
             name = contributor.get('name')
             role_names = contributor.get('roleName')