From bd5386356a9836ad377a933dbb79a8b2ecaf8a5f Mon Sep 17 00:00:00 2001
From: KyryloKireiev <kirillkireev888@gmail.com>
Date: Tue, 31 Oct 2023 16:02:36 +0200
Subject: [PATCH] feat: [FC-0031] Add optional field 'is_enrolled' to course
 detail view

---
 lms/djangoapps/course_api/serializers.py      | 11 +++++
 .../course_api/tests/test_serializers.py      | 43 +++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/lms/djangoapps/course_api/serializers.py b/lms/djangoapps/course_api/serializers.py
index dbf4736d4e89..e4855e05cb15 100644
--- a/lms/djangoapps/course_api/serializers.py
+++ b/lms/djangoapps/course_api/serializers.py
@@ -5,6 +5,8 @@
 
 import urllib
 
+from common.djangoapps.student.models import CourseEnrollment
+from django.contrib.auth import get_user_model
 from django.urls import reverse
 from edx_django_utils import monitoring as monitoring_utils
 from rest_framework import serializers
@@ -164,10 +166,19 @@ def to_representation(self, instance):
         """
         Get the `certificate_available_date` in response
         if the `certificates.auto_certificate_generation` waffle switch is enabled
+
+        Get the 'is_enrolled' in response
+        if user is authenticated and 'username' is in query params.
         """
         response = super().to_representation(instance)
         if can_show_certificate_available_date_field(instance):
             response['certificate_available_date'] = instance.certificate_available_date
+
+        requested_user = self.context['request'].query_params.get('username', None)
+        if self.context['request'].user.is_authenticated and requested_user:
+            User = get_user_model()
+            requested_user = User.objects.get(username=requested_user)
+            response['is_enrolled'] = CourseEnrollment.is_enrolled(requested_user, instance.id)
         return response
 
 
diff --git a/lms/djangoapps/course_api/tests/test_serializers.py b/lms/djangoapps/course_api/tests/test_serializers.py
index ec11fc05de66..b6069896aefe 100644
--- a/lms/djangoapps/course_api/tests/test_serializers.py
+++ b/lms/djangoapps/course_api/tests/test_serializers.py
@@ -188,6 +188,49 @@ def test_basic(self):
             )
         self.assertDictEqual(result, self.expected_data)
 
+    @mock.patch('lms.djangoapps.course_api.serializers.CourseEnrollment.is_enrolled', return_value=True)
+    def test_is_enrolled_field_true(self, mock_is_enrolled):
+        course = self.create_course()
+        result = self._get_result_with_query_param(course)
+        assert result['is_enrolled'] is True
+        mock_is_enrolled.assert_called_once()
+
+    @mock.patch('lms.djangoapps.course_api.serializers.CourseEnrollment.is_enrolled', return_value=False)
+    def test_is_enrolled_field_false(self, mock_is_enrolled):
+        course = self.create_course()
+        result = self._get_result_with_query_param(course)
+        assert result['is_enrolled'] is False
+        mock_is_enrolled.assert_called_once()
+
+    def test_is_enrolled_field_anonymous_user(self):
+        course = self.create_course()
+        result = self._get_anonymous_result(course)
+        self.assertNotIn('is_enrolled', result)
+
+    def _get_anonymous_request(self):
+        return Request(self.request_factory.get('/'))
+
+    def _get_anonymous_result(self, course):
+        course_overview = CourseOverview.get_from_id(course.id)
+        return self.serializer_class(course_overview, context={'request': self._get_anonymous_request()}).data
+
+    def _get_result_with_query_param(self, course):
+        """
+        Return the CourseSerializer for the specified course with 'username' in query params.
+        """
+        course_overview = CourseOverview.get_from_id(course.id)
+        return self.serializer_class(course_overview, context={'request': self._get_request_with_query_param()}).data
+
+    def _get_request_with_query_param(self, user=None):
+        """
+        Build a Request object for the specified user with 'username' in query params.
+        """
+        if user is None:
+            user = self.honor_user
+        request = Request(self.request_factory.get('/', {'username': user.username}))
+        request.user = user
+        return request
+
 
 class TestCourseKeySerializer(TestCase):  # lint-amnesty, pylint: disable=missing-class-docstring