fix: Ignore passing signal if the cert status is already downloadable (#27403)

MICROBA-1106

lms/djangoapps/certificates/models.py

@@ -55,8 +55,7 @@ class CertificateStatuses:
     invalidated         - Certificate is not valid.
     notpassing          - The user has not achieved a passing grade.
     requesting          - A request has been made to generate the PDF certificate.
-    restricted          - The user is on the restricted list. This status was previously set if allow_certificate was
-                          set to False in the userprofile table.
+    restricted          - The user is restricted from receiving a certificate.
     unavailable         - Certificate has been invalidated.
     unverified          - The user does not have an approved, unexpired identity verification.
 

lms/djangoapps/certificates/signals.py

@@ -75,13 +75,19 @@ def _listen_for_certificate_whitelist_append(sender, instance, **kwargs):  # pyl
 @receiver(COURSE_GRADE_NOW_PASSED, dispatch_uid="new_passing_learner")
 def listen_for_passing_grade(sender, user, course_id, **kwargs):  # pylint: disable=unused-argument
     """
-    Listen for a learner passing a course, send cert generation task,
-    downstream signal from COURSE_GRADE_CHANGED
+    Listen for a signal indicating that the user has passed a course run.
+
+    If needed, generate a certificate task.
     """
     if not auto_certificate_generation_enabled():
         return
 
     if can_generate_certificate_task(user, course_id):
+        cert = GeneratedCertificate.certificate_for_student(user, course_id)
+        if cert is not None and CertificateStatuses.is_passing_status(cert.status):
+            log.info(f'{course_id} is using V2 certificates, and the cert status is already passing for user '
+                     f'{user.id}. Passing grade signal will be ignored.')
+            return
         log.info(f'{course_id} is using V2 certificates. Attempt will be made to generate a V2 certificate for '
                  f'{user.id} as a passing grade was received.')
         return generate_certificate_task(user, course_id)
@@ -96,9 +102,9 @@ def listen_for_passing_grade(sender, user, course_id, **kwargs):  # pylint: disa
 @receiver(COURSE_GRADE_NOW_FAILED, dispatch_uid="new_failing_learner")
 def _listen_for_failing_grade(sender, user, course_id, grade, **kwargs):  # pylint: disable=unused-argument
     """
-    Listen for a learner failing a course, mark the cert as notpassing
-    if it is currently passing,
-    downstream signal from COURSE_GRADE_CHANGED
+    Listen for a signal indicating that the user has failed a course run.
+
+    If needed, mark the certificate as notpassing.
     """
     if is_using_certificate_allowlist_and_is_on_allowlist(user, course_id):
         log.info('{course_id} is using allowlist certificates, and the user {user_id} is on its allowlist. The '
@@ -119,8 +125,9 @@ def _listen_for_failing_grade(sender, user, course_id, grade, **kwargs):  # pyli
 @receiver(LEARNER_NOW_VERIFIED, dispatch_uid="learner_track_changed")
 def _listen_for_id_verification_status_changed(sender, user, **kwargs):  # pylint: disable=unused-argument
     """
-    Catches a track change signal, determines user status,
-    calls _fire_ungenerated_certificate_task for passing grades
+    Listen for a signal indicating that the user's id verification status has changed.
+
+    If needed, generate a certificate task.
     """
     if not auto_certificate_generation_enabled():
         return

lms/djangoapps/certificates/tests/test_signals.py

@@ -12,7 +12,10 @@ from edx_toggles.toggles.testutils import override_waffle_flag, override_waffle_
 
 from common.djangoapps.student.tests.factories import CourseEnrollmentFactory, UserFactory
 from lms.djangoapps.certificates.api import cert_generation_enabled
-from lms.djangoapps.certificates.generation_handler import CERTIFICATES_USE_ALLOWLIST
+from lms.djangoapps.certificates.generation_handler import (
+    CERTIFICATES_USE_ALLOWLIST,
+    CERTIFICATES_USE_UPDATED
+)
 from lms.djangoapps.certificates.models import (
     CertificateGenerationConfiguration,
     CertificateStatuses,
@@ -217,6 +220,7 @@ class PassingGradeCertsTest(ModuleStoreTestCase):
         self.course = CourseFactory.create(
             self_paced=True,
         )
+        self.course_key = self.course.id
         self.user = UserFactory.create()
         self.enrollment = CourseEnrollmentFactory(
             user=self.user,
@@ -334,6 +338,54 @@ class PassingGradeCertsTest(ModuleStoreTestCase):
                     CourseGradeFactory().update(u, c)
                     mock_cert_task.assert_called_with(u, course_key)
 
+    @override_waffle_flag(CERTIFICATES_USE_UPDATED, active=True)
+    def test_cert_already_generated_downloadable(self):
+        with override_waffle_switch(AUTO_CERTIFICATE_GENERATION_SWITCH, active=True):
+            GeneratedCertificateFactory(
+                user=self.user,
+                course_id=self.course.id,
+                status=CertificateStatuses.downloadable
+            )
+
+            with mock.patch(
+                'lms.djangoapps.certificates.signals.generate_certificate_task',
+                return_value=None
+            ) as mock_cert_task:
+                grade_factory = CourseGradeFactory()
+                with mock_passing_grade():
+                    grade_factory.update(self.user, self.course)
+                    mock_cert_task.assert_not_called()
+
+    @override_waffle_flag(CERTIFICATES_USE_UPDATED, active=True)
+    def test_cert_already_generated_unverified(self):
+        with override_waffle_switch(AUTO_CERTIFICATE_GENERATION_SWITCH, active=True):
+            GeneratedCertificateFactory(
+                user=self.user,
+                course_id=self.course.id,
+                status=CertificateStatuses.unverified
+            )
+
+            with mock.patch(
+                'lms.djangoapps.certificates.signals.generate_certificate_task',
+                return_value=None
+            ) as mock_cert_task:
+                grade_factory = CourseGradeFactory()
+                with mock_passing_grade():
+                    grade_factory.update(self.user, self.course)
+                    mock_cert_task.assert_called_with(self.user, self.course_key)
+
+    @override_waffle_flag(CERTIFICATES_USE_UPDATED, active=True)
+    def test_without_cert(self):
+        with override_waffle_switch(AUTO_CERTIFICATE_GENERATION_SWITCH, active=True):
+            with mock.patch(
+                'lms.djangoapps.certificates.signals.generate_certificate_task',
+                return_value=None
+            ) as mock_cert_task:
+                grade_factory = CourseGradeFactory()
+                with mock_passing_grade():
+                    grade_factory.update(self.user, self.course)
+                    mock_cert_task.assert_called_with(self.user, self.course_key)
+
 
 @ddt.ddt
 class FailingGradeCertsTest(ModuleStoreTestCase):