fix: simplify most recent verification function

current use is much less complicated than old code

lms/djangoapps/verify_student/services.py

@@ -116,18 +116,11 @@ class IDVerificationService:
             'status__in': statuses,
         }
 
-        sort_by = 'updated_at'
+        photo_id_verifications = SoftwareSecurePhotoVerification.objects.filter(**filter_kwargs)
+        sso_id_verifications = SSOVerification.objects.filter(**filter_kwargs)
+        manual_id_verifications = ManualVerification.objects.filter(**filter_kwargs)
 
-        photo_id_verifications = SoftwareSecurePhotoVerification.objects.filter(**filter_kwargs).order_by('-' + sort_by)
-        sso_id_verifications = SSOVerification.objects.filter(**filter_kwargs).order_by('-' + sort_by)
-        manual_id_verifications = ManualVerification.objects.filter(**filter_kwargs).order_by('-' + sort_by)
-
-        attempt = most_recent_verification(
-            photo_id_verifications,
-            sso_id_verifications,
-            manual_id_verifications,
-            sort_by
-        )
+        attempt = most_recent_verification((photo_id_verifications, sso_id_verifications, manual_id_verifications))
         return attempt and attempt.expiration_datetime
 
     @classmethod

lms/djangoapps/verify_student/tests/test_utils.py

@@ -129,14 +129,16 @@ class TestVerifyStudentUtils(unittest.TestCase):
             sso_verification = SSOVerification.objects.create(user=user)
             photo_verification = SoftwareSecurePhotoVerification.objects.create(user=user)
         else:
+            #last first = manual expected = photo case adds some duplicates for complexity
+            ManualVerification.objects.create(user=user)
+            SoftwareSecurePhotoVerification.objects.create(user=user)
             manual_verification = ManualVerification.objects.create(user=user)
             photo_verification = SoftwareSecurePhotoVerification.objects.create(user=user)
 
         most_recent = most_recent_verification(
-            SoftwareSecurePhotoVerification.objects.all(),
-            SSOVerification.objects.all(),
-            ManualVerification.objects.all(),
-            'created_at'
+            (SoftwareSecurePhotoVerification.objects.all(),
+             SSOVerification.objects.all(),
+             ManualVerification.objects.all())
         )
 
         if not expected_verification:

lms/djangoapps/verify_student/utils.py

@@ -105,35 +105,23 @@ def verification_for_datetime(deadline, candidates):
         return None
 
 
-def most_recent_verification(photo_id_verifications, sso_id_verifications, manual_id_verifications, most_recent_key):
+def most_recent_verification(verification_sets):
     """
-    Return the most recent verification given querysets for photo, sso and manual verifications.
-
-    This function creates a map of the latest verification of all types and then returns the earliest
-    verification using the max of the map values.
+    Return the most recent verification (by updated date) given querysets for multiple types of verifications.
+    Photo, sso and manual are the current use.
 
     Arguments:
-        photo_id_verifications: Queryset containing photo verifications
-        sso_id_verifications: Queryset containing sso verifications
-        manual_id_verifications: Queryset containing manual verifications
-        most_recent_key: Either 'updated_at' or 'created_at'
+        tuple or other iterable of verification sets
 
     Returns:
         The most recent verification.
     """
-    photo_id_verification = photo_id_verifications and photo_id_verifications.first()
-    sso_id_verification = sso_id_verifications and sso_id_verifications.first()
-    manual_id_verification = manual_id_verifications and manual_id_verifications.first()
-
-    verifications = [photo_id_verification, sso_id_verification, manual_id_verification]
-
-    verifications_map = {
-        verification: getattr(verification, most_recent_key)
-        for verification in verifications
-        if getattr(verification, most_recent_key, False)
-    }
-
-    return max(verifications_map, key=lambda k: verifications_map[k]) if verifications_map else None
+    most_recent = None
+    for s in verification_sets:
+        for v in s:
+            if not most_recent or v.updated_at > most_recent.updated_at:
+                most_recent = v
+    return most_recent
 
 
 def auto_verify_for_testing_enabled(override=None):