fix: fixed atmoic block error in course_status_info

* fix: fixed atmoic block error in course_status_info

We are getting "An error occurred in the current transaction. You cant execute queries until the end of the atomic block."
error in get course status info on both versions i.e. 0.5 and 1. I was unable to reproduce it locally. But by looking
in django documentation and some other online helps I concluded that it might be because of some db intefrity error
that we didnt handle properly and now the cursor is broken for this transaction. Therefore i am making it non atomic
transaction. Since its a get request we can make transactions run independentantly.

LEARNER-8267

lms/djangoapps/mobile_api/users/tests.py

@@ -11,15 +11,17 @@ import ddt
 import pytz
 from completion.test_utils import CompletionWaffleTestMixin, submit_completions_for_testing
 from django.conf import settings
+from django.db import transaction
 from django.template import defaultfilters
 from django.test import RequestFactory, override_settings
 from django.utils import timezone
 from django.utils.timezone import now
 from milestones.tests.utils import MilestonesTestCaseMixin
+from opaque_keys.edx.keys import CourseKey
 
 from common.djangoapps.course_modes.models import CourseMode
 from common.djangoapps.student.models import CourseEnrollment
-from common.djangoapps.student.tests.factories import CourseEnrollmentFactory
+from common.djangoapps.student.tests.factories import CourseEnrollmentFactory, UserFactory
 from common.djangoapps.util.milestones_helpers import set_prerequisite_courses
 from common.djangoapps.util.testing import UrlResetMixin
 from lms.djangoapps.certificates.data import CertificateStatuses
@@ -439,6 +441,7 @@ class TestCourseStatusGET(CourseStatusAPITestCase, MobileAuthUserTestMixin,
     """
     Tests for GET of /api/mobile/v<version_number>/users/<user_name>/course_status_info/{course_id}
     """
+
     def test_success_v0(self):
         self.login_and_enroll()
 
@@ -454,6 +457,53 @@ class TestCourseStatusGET(CourseStatusAPITestCase, MobileAuthUserTestMixin,
         response = self.api_response(api_version=API_V1)
         assert response.data['last_visited_block_id'] == str(self.unit.location)
 
+    # Since we are testing an non atomic view in atomic test case, therefore we are expecting error on failures
+    def api_error_response(self, reverse_args=None, data=None, **kwargs):
+        """
+            Same as api response from MobileAPITestCase but handle views which throw errors
+        """
+        url = self.reverse_url(reverse_args, **kwargs)
+        try:
+            with transaction.atomic():
+                self.url_method(url, data=data, **kwargs)
+                assert False
+        except transaction.TransactionManagementError:
+            assert True
+
+    def test_invalid_user(self):
+        self.login_and_enroll()
+        self.api_error_response(username='no_user')
+
+    def test_other_user(self):
+        # login and enroll as the test user
+        self.login_and_enroll()
+        self.logout()
+
+        # login and enroll as another user
+        other = UserFactory.create()
+        self.client.login(username=other.username, password='test')
+        self.enroll()
+        self.logout()
+
+        # now login and call the API as the test user
+        self.login()
+        self.api_error_response(username=other.username)
+
+    def test_course_not_found(self):
+        non_existent_course_id = CourseKey.from_string('a/b/c')
+        self.init_course_access(course_id=non_existent_course_id)
+
+        self.api_error_response(course_id=non_existent_course_id)
+
+    def test_unenrolled_user(self):
+        self.login()
+        self.unenroll()
+        self.api_error_response(expected_response_code=None)
+
+    def test_no_auth(self):
+        self.logout()
+        self.api_error_response()
+
 
 class TestCourseStatusPATCH(CourseStatusAPITestCase, MobileAuthUserTestMixin,
                             MobileCourseAccessTestMixin, MilestonesTestCaseMixin):

lms/djangoapps/mobile_api/users/views.py

@@ -7,12 +7,15 @@ from completion.exceptions import UnavailableCompletionData
 from completion.utilities import get_key_to_last_completed_block
 from django.contrib.auth.models import User  # lint-amnesty, pylint: disable=imported-auth-user
 from django.contrib.auth.signals import user_logged_in
+from django.db import transaction
 from django.shortcuts import redirect
 from django.utils import dateparse
+from django.utils.decorators import method_decorator
 from opaque_keys import InvalidKeyError
 from opaque_keys.edx.keys import UsageKey
 from rest_framework import generics, views
 from rest_framework.decorators import api_view
+from rest_framework.permissions import SAFE_METHODS
 from rest_framework.response import Response
 from xblock.fields import Scope
 from xblock.runtime import KeyValueStore
@@ -77,6 +80,7 @@ class UserDetail(generics.RetrieveAPIView):
 
 
 @mobile_view(is_user=True)
+@method_decorator(transaction.non_atomic_requests, name='dispatch')
 class UserCourseStatus(views.APIView):
     """
     **Use Cases**
@@ -122,6 +126,13 @@ class UserCourseStatus(views.APIView):
 
     http_method_names = ["get", "patch"]
 
+    def dispatch(self, request, *args, **kwargs):
+        if request.method in SAFE_METHODS:
+            return super().dispatch(request, *args, **kwargs)
+        else:
+            with transaction.atomic():
+                return super().dispatch(request, *args, **kwargs)
+
     def _last_visited_module_path(self, request, course):
         """
         Returns the path from the last module visited by the current user in the given course up to
@@ -135,7 +146,7 @@ class UserCourseStatus(views.APIView):
             request.user, request, course, field_data_cache, course.id, course=course
         )
 
-        path = [course_module]
+        path = [course_module] if course_module else []
         chapter = get_current_child(course_module, min_depth=2)
         if chapter is not None:
             path.append(chapter)