fix: return certificate_available_date in courses list API response

lms/djangoapps/course_api/serializers.py

@@ -139,6 +139,12 @@ def get_blocks_url(self, course_overview):
         ])
         return self.context['request'].build_absolute_uri(base_url)
 
+    def to_representation(self, instance):
+        response = super().to_representation(instance)
+        if can_show_certificate_available_date_field(instance):
+            response['certificate_available_date'] = instance.certificate_available_date
+        return response
+
 
 class CourseDetailSerializer(CourseSerializer):  # pylint: disable=abstract-method
     """

lms/djangoapps/course_api/tests/test_serializers.py

@@ -142,6 +142,31 @@ def test_pacing(self, self_paced, expected_pacing):
         result = self._get_result(course)
         assert result['pacing'] == expected_pacing
 
+    def test_certificate_available_date_included(self):
+        """Test that certificate_available_date is included when the field should be shown."""
+        course = self.create_course()
+        with mock.patch(
+            "lms.djangoapps.course_api.serializers.can_show_certificate_available_date_field",
+            return_value=True,
+        ):
+            result = self._get_result(course)
+        assert 'certificate_available_date' in result
+        actual = result['certificate_available_date']
+        if isinstance(actual, datetime):
+            assert actual.strftime('%Y-%m-%dT%H:%M:%SZ') == '2015-08-14T00:00:00Z'
+        else:
+            assert actual == '2015-08-14T00:00:00Z'
+
+    def test_certificate_available_date_excluded(self):
+        """Test that certificate_available_date is excluded when the field should not be shown."""
+        course = self.create_course()
+        with mock.patch(
+            "lms.djangoapps.course_api.serializers.can_show_certificate_available_date_field",
+            return_value=False,
+        ):
+            result = self._get_result(course)
+        assert 'certificate_available_date' not in result
+
 
 class TestCourseDetailSerializer(TestCourseSerializer):  # pylint: disable=test-inherits-tests
     """