refactor: use q objects when fetching user using an identifier #26683 (#26823)

lms/djangoapps/certificates/management/commands/cert_whitelist.py

@@ -6,6 +6,7 @@ user/course
 
 from django.contrib.auth import get_user_model
 from django.core.management.base import BaseCommand, CommandError
+from django.db.models import Q
 from opaque_keys.edx.keys import CourseKey
 
 from lms.djangoapps.certificates.models import CertificateWhitelist
@@ -17,11 +18,9 @@ def get_user_from_identifier(identifier):
     """
      This function takes the string identifier and fetch relevant user object from database
     """
-    identifier = identifier.strip()
-    if '@' in identifier:
-        user = User.objects.get(email=identifier)
-    else:
-        user = User.objects.get(username=identifier)
+    user = User.objects.filter(Q(username=identifier) | Q(email=identifier)).first()
+    if not user:
+        raise CommandError("User {} does not exist.".format(identifier))
     return user
 
 
@@ -103,7 +102,8 @@ class Command(BaseCommand):
             add_to_whitelist = True if options['add'] else False  # pylint: disable=simplifiable-if-expression
             users_list = user_str.split(",")
             for username in users_list:
-                if username.strip():
+                username = username.strip()
+                if username:
                     update_user_whitelist(username, add=add_to_whitelist)
 
         whitelist = CertificateWhitelist.objects.filter(course_id=course)

lms/djangoapps/certificates/management/commands/tests/test_cert_whitelist.py

@@ -1,10 +1,10 @@
 """
 Extremely basic tests for the cert_whitelist command
 """
-
-
+import ddt
 import pytest
-from django.core.management import call_command
+from django.core.management import call_command, CommandError
+from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
 
 
 def test_cert_whitelist_help(capsys):
@@ -16,3 +16,22 @@ def test_cert_whitelist_help(capsys):
 
     out, err = capsys.readouterr()  # pylint: disable=unused-variable
     assert "COURSE_ID" in out
+
+
+@ddt.ddt
+class CertWhitelistGenerationTests(ModuleStoreTestCase):
+    """
+    Tests for the cert_whitelist management command.
+    """
+    @ddt.data(
+        'jeo',
+        'jeo@edx.org',
+        'robo_user, jenny, tom, jerry'
+    )
+    def test_user_not_found(self, user_identifier):
+        """
+        Basic test to see if the command will raise user not found error.
+        """
+        error_identifier = user_identifier.split(',')[0].strip()
+        with pytest.raises(CommandError, match=f"User {error_identifier} does not exist"):
+            call_command('cert_whitelist', '--add', user_identifier, '-c', 'MITx/6.002x/2012_Fall')