From 6c87142629f139c038621bad8a4a8777013eafd9 Mon Sep 17 00:00:00 2001
From: javier ontiveros <javier.ontiveros@wgu.edu>
Date: Wed, 17 Dec 2025 14:39:29 -0600
Subject: [PATCH 1/8] chore: base work for unit extensions v2 api

---
 .../instructor/tests/test_api_v2.py           | 407 ++++++++++++++++++
 lms/djangoapps/instructor/views/api_urls.py   |   5 +
 lms/djangoapps/instructor/views/api_v2.py     | 180 ++++++++
 .../instructor/views/serializers_v2.py        |  27 ++
 4 files changed, 619 insertions(+)

diff --git a/lms/djangoapps/instructor/tests/test_api_v2.py b/lms/djangoapps/instructor/tests/test_api_v2.py
index 510de37e37b5..5a901fb7e1b0 100644
--- a/lms/djangoapps/instructor/tests/test_api_v2.py
+++ b/lms/djangoapps/instructor/tests/test_api_v2.py
@@ -890,3 +890,410 @@ def test_get_graded_subsections_response_format(self):
             self.assertIn('subsection_id', item)
             self.assertIsInstance(item['display_name'], str)
             self.assertIsInstance(item['subsection_id'], str)
+
+
+@ddt.ddt
+class UnitExtensionsViewTest(SharedModuleStoreTestCase):
+    """
+    Tests for the UnitExtensionsView API endpoint.
+    """
+
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        cls.course = CourseFactory.create(
+            org='edX',
+            number='TestX',
+            run='Test_Course',
+            display_name='Test Course',
+        )
+        cls.course_key = cls.course.id
+
+        # Create course structure with due dates
+        cls.chapter = BlockFactory.create(
+            parent=cls.course,
+            category='chapter',
+            display_name='Test Chapter'
+        )
+        cls.due_date = datetime(2024, 12, 31, 23, 59, 59, tzinfo=UTC)
+        cls.subsection = BlockFactory.create(
+            parent=cls.chapter,
+            category='sequential',
+            display_name='Homework 1',
+            due=cls.due_date
+        )
+        cls.vertical = BlockFactory.create(
+            parent=cls.subsection,
+            category='vertical',
+            display_name='Test Vertical'
+        )
+        cls.problem = BlockFactory.create(
+            parent=cls.vertical,
+            category='problem',
+            display_name='Test Problem'
+        )
+
+    def setUp(self):
+        super().setUp()
+        self.client = APIClient()
+        self.instructor = InstructorFactory.create(course_key=self.course_key)
+        self.staff = StaffFactory.create(course_key=self.course_key)
+        self.student1 = UserFactory.create(username='student1', email='student1@example.com')
+        self.student2 = UserFactory.create(username='student2', email='student2@example.com')
+
+        # Enroll students
+        CourseEnrollmentFactory.create(
+            user=self.student1,
+            course_id=self.course_key,
+            is_active=True
+        )
+        CourseEnrollmentFactory.create(
+            user=self.student2,
+            course_id=self.course_key,
+            is_active=True
+        )
+
+    def _get_url(self, course_id=None):
+        """Helper to get the API URL."""
+        if course_id is None:
+            course_id = str(self.course_key)
+        return reverse('instructor_api_v2:unit_extensions', kwargs={'course_id': course_id})
+
+    def test_get_unit_extensions_success(self):
+        """
+        Test that an instructor can retrieve paginated unit extensions.
+        """
+        self.client.force_authenticate(user=self.instructor)
+        response = self.client.get(self._get_url())
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        data = response.data
+
+        # Verify pagination structure
+        self.assertIn('count', data)
+        self.assertIn('next', data)
+        self.assertIn('previous', data)
+        self.assertIn('results', data)
+        self.assertIsInstance(data['results'], list)
+
+    def test_get_unit_extensions_as_staff(self):
+        """
+        Test that staff can retrieve unit extensions.
+        """
+        self.client.force_authenticate(user=self.staff)
+        response = self.client.get(self._get_url())
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+
+    def test_get_unit_extensions_unauthorized(self):
+        """
+        Test that students cannot access unit extensions endpoint.
+        """
+        self.client.force_authenticate(user=self.student1)
+        response = self.client.get(self._get_url())
+
+        self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
+
+    def test_get_unit_extensions_unauthenticated(self):
+        """
+        Test that unauthenticated users cannot access the endpoint.
+        """
+        response = self.client.get(self._get_url())
+        self.assertEqual(response.status_code, status.HTTP_401_UNAUTHORIZED)
+
+    def test_get_unit_extensions_nonexistent_course(self):
+        """
+        Test error handling for non-existent course.
+        """
+        self.client.force_authenticate(user=self.instructor)
+        nonexistent_course_id = 'course-v1:edX+NonExistent+2024'
+        response = self.client.get(self._get_url(course_id=nonexistent_course_id))
+
+        self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
+
+    @patch('lms.djangoapps.instructor.views.api_v2.edx_when_api.get_overrides_for_course')
+    @patch('lms.djangoapps.instructor.views.api_v2.get_units_with_due_date')
+    def test_get_unit_extensions_with_data(self, mock_get_units, mock_get_overrides):
+        """
+        Test unit extensions with mocked data.
+        """
+        # Mock units with due dates
+        mock_unit = Mock()
+        mock_unit.display_name = 'Homework 1'
+        mock_unit.location = Mock()
+        mock_unit.location.__str__ = Mock(return_value='block-v1:Test+Course+2024+type@sequential+block@hw1')
+        mock_get_units.return_value = [mock_unit]
+
+        # Mock location for dictionary lookup
+        mock_location = Mock()
+        mock_location.__str__ = Mock(return_value='block-v1:Test+Course+2024+type@sequential+block@hw1')
+
+        # Mock course overrides data (username, full_name, email, location, due_date)
+        extended_date = datetime(2025, 1, 15, 23, 59, 59, tzinfo=UTC)
+        mock_get_overrides.return_value = [
+            ('student1', 'John Doe', 'john@example.com', mock_location, extended_date),
+            ('student2', 'Jane Smith', 'jane@example.com', mock_location, extended_date),
+        ]
+
+        self.client.force_authenticate(user=self.instructor)
+        response = self.client.get(self._get_url())
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        data = response.data
+        results = data['results']
+
+        self.assertGreaterEqual(len(results), 0)
+
+        # If there are results, verify the structure
+        if results:
+            extension = results[0]
+            expected_fields = [
+                'username', 'full_name', 'email',
+                'unit_title', 'unit_location', 'extended_due_date'
+            ]
+            for field in expected_fields:
+                self.assertIn(field, extension)
+
+    @patch('lms.djangoapps.instructor.views.api_v2.edx_when_api.get_overrides_for_course')
+    @patch('lms.djangoapps.instructor.views.api_v2.get_units_with_due_date')
+    def test_filter_by_email_or_username(self, mock_get_units, mock_get_overrides):
+        """
+        Test filtering unit extensions by email or username.
+        """
+        # Mock units with due dates
+        mock_unit = Mock()
+        mock_unit.display_name = 'Homework 1'
+        mock_unit.location = Mock()
+        mock_unit.location.__str__ = Mock(return_value='block-v1:Test+Course+2024+type@sequential+block@hw1')
+        mock_get_units.return_value = [mock_unit]
+
+        # Mock location for dictionary lookup
+        mock_location = Mock()
+        mock_location.__str__ = Mock(return_value='block-v1:Test+Course+2024+type@sequential+block@hw1')
+
+        # Mock course overrides data
+        extended_date = datetime(2025, 1, 15, 23, 59, 59, tzinfo=UTC)
+        mock_get_overrides.return_value = [
+            ('student1', 'John Doe', 'john@example.com', mock_location, extended_date),
+            ('student2', 'Jane Smith', 'jane@example.com', mock_location, extended_date),
+        ]
+
+        self.client.force_authenticate(user=self.instructor)
+
+        # Test filter by username
+        params = {'email_or_username': 'student1'}
+        url = f"{self._get_url()}?{urlencode(params)}"
+        response = self.client.get(url)
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        # The filter logic should be called
+        mock_get_overrides.assert_called()
+
+        # Test filter by email
+        params = {'email_or_username': 'jane@example.com'}
+        url = f"{self._get_url()}?{urlencode(params)}"
+        response = self.client.get(url)
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+
+    @patch('lms.djangoapps.instructor.views.api_v2.edx_when_api.get_overrides_for_block')
+    @patch('lms.djangoapps.instructor.views.api_v2.find_unit')
+    @patch('lms.djangoapps.instructor.views.api_v2.get_units_with_due_date')
+    def test_filter_by_block_id(self, mock_get_units, mock_find_unit, mock_get_overrides_block):
+        """
+        Test filtering unit extensions by specific block_id.
+        """
+        # Mock unit
+        mock_unit = Mock()
+        mock_unit.display_name = 'Homework 1'
+        mock_unit.location = Mock()
+        mock_unit.location.__str__ = Mock(return_value='block-v1:Test+Course+2024+type@sequential+block@hw1')
+
+        mock_find_unit.return_value = mock_unit
+        mock_get_units.return_value = [mock_unit]
+
+        # Mock block-specific overrides data (username, full_name, due_date)
+        extended_date = datetime(2025, 1, 15, 23, 59, 59, tzinfo=UTC)
+        mock_get_overrides_block.return_value = [
+            ('student1', 'John Doe', extended_date),
+        ]
+
+        self.client.force_authenticate(user=self.instructor)
+        params = {'block_id': 'block-v1:Test+Course+2024+type@sequential+block@hw1'}
+        url = f"{self._get_url()}?{urlencode(params)}"
+        response = self.client.get(url)
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+
+        # Verify the block-specific API was called
+        mock_get_overrides_block.assert_called_once()
+        mock_find_unit.assert_called_once()
+
+    @patch('lms.djangoapps.instructor.views.api_v2.find_unit')
+    def test_filter_by_invalid_block_id(self, mock_find_unit):
+        """
+        Test filtering by invalid block_id returns empty list.
+        """
+        # Make find_unit raise an exception
+        mock_find_unit.side_effect = Exception('Invalid block')
+
+        self.client.force_authenticate(user=self.instructor)
+        params = {'block_id': 'invalid-block-id'}
+        url = f"{self._get_url()}?{urlencode(params)}"
+        response = self.client.get(url)
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        data = response.data
+        self.assertEqual(data['count'], 0)
+        self.assertEqual(data['results'], [])
+
+    @patch('lms.djangoapps.instructor.views.api_v2.edx_when_api.get_overrides_for_block')
+    @patch('lms.djangoapps.instructor.views.api_v2.find_unit')
+    def test_combined_filters(self, mock_find_unit, mock_get_overrides_block):
+        """
+        Test combining block_id and email_or_username filters.
+        """
+        # Mock unit
+        mock_unit = Mock()
+        mock_unit.display_name = 'Homework 1'
+        mock_unit.location = Mock()
+        mock_unit.location.__str__ = Mock(return_value='block-v1:Test+Course+2024+type@sequential+block@hw1')
+
+        mock_find_unit.return_value = mock_unit
+
+        # Mock block-specific overrides data
+        extended_date = datetime(2025, 1, 15, 23, 59, 59, tzinfo=UTC)
+        mock_get_overrides_block.return_value = [
+            ('student1', 'John Doe', extended_date),
+            ('student2', 'Jane Smith', extended_date),
+        ]
+
+        self.client.force_authenticate(user=self.instructor)
+        params = {
+            'block_id': 'block-v1:Test+Course+2024+type@sequential+block@hw1',
+            'email_or_username': 'student1'
+        }
+        url = f"{self._get_url()}?{urlencode(params)}"
+        response = self.client.get(url)
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        # Both filters should be applied
+        mock_get_overrides_block.assert_called_once()
+        mock_find_unit.assert_called_once()
+
+    def test_pagination_parameters(self):
+        """
+        Test that pagination parameters work correctly.
+        """
+        self.client.force_authenticate(user=self.instructor)
+
+        # Test page parameter
+        params = {'page': '1', 'page_size': '10'}
+        url = f"{self._get_url()}?{urlencode(params)}"
+        response = self.client.get(url)
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        data = response.data
+        self.assertIn('count', data)
+        self.assertIn('next', data)
+        self.assertIn('previous', data)
+        self.assertIn('results', data)
+
+    @patch('lms.djangoapps.instructor.views.api_v2.edx_when_api.get_overrides_for_course')
+    @patch('lms.djangoapps.instructor.views.api_v2.get_units_with_due_date')
+    def test_empty_results(self, mock_get_units, mock_get_overrides):
+        """
+        Test endpoint with no extension data.
+        """
+        # Mock empty data
+        mock_get_units.return_value = []
+        mock_get_overrides.return_value = []
+
+        self.client.force_authenticate(user=self.instructor)
+        response = self.client.get(self._get_url())
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        data = response.data
+        self.assertEqual(data['count'], 0)
+        self.assertEqual(data['results'], [])
+
+    @patch('lms.djangoapps.instructor.views.api_v2.edx_when_api.get_overrides_for_course')
+    @patch('lms.djangoapps.instructor.views.api_v2.get_units_with_due_date')
+    @patch('lms.djangoapps.instructor.views.api_v2.title_or_url')
+    def test_extension_data_structure(self, mock_title_or_url, mock_get_units, mock_get_overrides):
+        """
+        Test that extension data has the correct structure.
+        """
+        # Mock units with due dates
+        mock_unit = Mock()
+        mock_unit.display_name = 'Homework 1'
+        mock_unit.location = Mock()
+        mock_unit.location.__str__ = Mock(return_value='block-v1:Test+Course+2024+type@sequential+block@hw1')
+        mock_get_units.return_value = [mock_unit]
+        mock_title_or_url.return_value = 'Homework 1'
+
+        # Mock location for dictionary lookup
+        mock_location = Mock()
+        mock_location.__str__ = Mock(return_value='block-v1:Test+Course+2024+type@sequential+block@hw1')
+
+        # Mock course overrides data
+        extended_date = datetime(2025, 1, 15, 23, 59, 59, tzinfo=UTC)
+        mock_get_overrides.return_value = [
+            ('student1', 'John Doe', 'john@example.com', mock_location, extended_date),
+        ]
+
+        self.client.force_authenticate(user=self.instructor)
+        response = self.client.get(self._get_url())
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        data = response.data
+
+        if data['results']:
+            extension = data['results'][0]
+
+            # Verify all required fields are present
+            required_fields = [
+                'username', 'full_name', 'email',
+                'unit_title', 'unit_location', 'extended_due_date'
+            ]
+            for field in required_fields:
+                self.assertIn(field, extension)
+
+            # Verify data types
+            self.assertIsInstance(extension['username'], str)
+            self.assertIsInstance(extension['full_name'], str)
+            self.assertIsInstance(extension['email'], str)
+            self.assertIsInstance(extension['unit_title'], str)
+            self.assertIsInstance(extension['unit_location'], str)
+
+    def test_response_content_type(self):
+        """
+        Test that the response has the correct content type.
+        """
+        self.client.force_authenticate(user=self.instructor)
+        response = self.client.get(self._get_url())
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(response['content-type'], 'application/json')
+
+    @ddt.data(
+        ('student1',),
+        ('john@example.com',),
+        ('STUDENT1',),  # Test case insensitive
+        ('JOHN@EXAMPLE.COM',),  # Test case insensitive
+    )
+    @ddt.unpack
+    def test_email_or_username_filter_variations(self, filter_value):
+        """
+        Test various formats for email_or_username filter.
+        """
+        self.client.force_authenticate(user=self.instructor)
+        params = {'email_or_username': filter_value}
+        url = f"{self._get_url()}?{urlencode(params)}"
+        response = self.client.get(url)
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        # Verify the response structure is correct regardless of filter
+        data = response.data
+        self.assertIn('count', data)
+        self.assertIn('results', data)
diff --git a/lms/djangoapps/instructor/views/api_urls.py b/lms/djangoapps/instructor/views/api_urls.py
index f23701cc1de7..083a3dc66204 100644
--- a/lms/djangoapps/instructor/views/api_urls.py
+++ b/lms/djangoapps/instructor/views/api_urls.py
@@ -40,6 +40,11 @@
         rf'^courses/{COURSE_ID_PATTERN}/graded_subsections$',
         api_v2.GradedSubsectionsView.as_view(),
         name='graded_subsections'
+    ),
+    re_path(
+        rf'^courses/{COURSE_ID_PATTERN}/unit_extensions$',
+        api_v2.UnitExtensionsView.as_view(),
+        name='unit_extensions'
     )
 ]
 
diff --git a/lms/djangoapps/instructor/views/api_v2.py b/lms/djangoapps/instructor/views/api_v2.py
index 709ad8f7e0f0..43664337e0b4 100644
--- a/lms/djangoapps/instructor/views/api_v2.py
+++ b/lms/djangoapps/instructor/views/api_v2.py
@@ -8,9 +8,11 @@
 import logging
 
 import edx_api_doc_tools as apidocs
+from edx_when import api as edx_when_api
 from opaque_keys import InvalidKeyError
 from opaque_keys.edx.keys import CourseKey, UsageKey
 from rest_framework import status
+from rest_framework.generics import ListAPIView
 from rest_framework.permissions import IsAuthenticated
 from rest_framework.response import Response
 from rest_framework.views import APIView
@@ -31,6 +33,7 @@
     InstructorTaskListSerializer,
     CourseInformationSerializerV2,
     BlockDueDateSerializerV2,
+    UnitExtensionSerializer,
 )
 from .tools import (
     find_unit,
@@ -349,3 +352,180 @@ def get(self, request, course_id):
             } for unit in graded_subsections]}
 
         return Response(formated_subsections, status=status.HTTP_200_OK)
+
+
+class UnitExtensionsView(ListAPIView):
+    """
+    **Use Cases**
+
+        Retrieve a paginated list of due date extensions for units in a course.
+
+    **Example Requests**
+
+        GET /api/instructor/v2/courses/{course_id}/unit_extensions
+        GET /api/instructor/v2/courses/{course_id}/unit_extensions?page=2
+        GET /api/instructor/v2/courses/{course_id}/unit_extensions?page_size=50
+        GET /api/instructor/v2/courses/{course_id}/unit_extensions?email_or_username=john
+        GET /api/instructor/v2/courses/{course_id}/unit_extensions?block_id=block-v1:org+course+run+type@problem+block@unit1
+
+    **Response Values**
+
+        {
+            "count": 150,
+            "next": "http://example.com/api/instructor/v2/courses/course-v1:org+course+run/unit_extensions?page=2",
+            "previous": null,
+            "results": [
+                {
+                    "username": "student1",
+                    "full_name": "John Doe",
+                    "email": "john.doe@example.com",
+                    "unit_title": "Unit 1: Introduction",
+                    "unit_location": "block-v1:org+course+run+type@problem+block@unit1",
+                    "extended_due_date": "2023-12-25T23:59:59Z"
+                },
+                ...
+            ]
+        }
+
+    **Parameters**
+
+        course_id: Course key for the course.
+        page (optional): Page number for pagination.
+        page_size (optional): Number of results per page.
+
+    **Returns**
+
+        * 200: OK - Returns paginated list of unit extensions
+        * 401: Unauthorized - User is not authenticated
+        * 403: Forbidden - User lacks instructor permissions
+        * 404: Not Found - Course does not exist
+    """
+    permission_classes = (IsAuthenticated, permissions.InstructorPermission)
+    permission_name = permissions.VIEW_DASHBOARD
+    serializer_class = UnitExtensionSerializer
+
+    @apidocs.schema(
+        parameters=[
+            apidocs.string_parameter(
+                'course_id',
+                apidocs.ParameterLocation.PATH,
+                description="Course key for the course.",
+            ),
+            apidocs.string_parameter(
+                'email_or_username',
+                apidocs.ParameterLocation.QUERY,
+                description="Optional: Filter by username or email address.",
+            ),
+            apidocs.string_parameter(
+                'block_id',
+                apidocs.ParameterLocation.QUERY,
+                description="Optional: Filter by specific unit/subsection location.",
+            ),
+        ],
+        responses={
+            200: UnitExtensionSerializer(many=True),
+            401: "The requesting user is not authenticated.",
+            403: "The requesting user lacks instructor permissions.",
+            404: "The requested course does not exist.",
+        },
+    )
+
+    def get_queryset(self):
+        """
+        Returns the queryset of unit extensions for the specified course.
+
+        This method uses the core logic from get_overrides_for_course to retrieve
+        due date extension data and transforms it into a list of dictionaries
+        that can be paginated and serialized.
+
+        Supports filtering by:
+        - email_or_username: Filter by username or email address
+        - block_id: Filter by specific unit/subsection location
+        """
+        course_id = self.kwargs['course_id']
+        course_key = CourseKey.from_string(course_id)
+        course = get_course_by_id(course_key)
+
+        # Get query parameters for filtering
+        email_or_username_filter = self.request.query_params.get('email_or_username', None)
+        block_id_filter = self.request.query_params.get('block_id', None)
+
+        # Get units with due dates for filtering
+        units = get_units_with_due_date(course)
+        units_dict = {u.location: u for u in units}
+
+        # If filtering by specific unit, use the block-specific logic
+        if block_id_filter:
+            try:
+                # Parse the block_id and find the unit
+                unit = find_unit(course, block_id_filter)
+
+                # Use the block-specific API call for better performance
+                query_data = edx_when_api.get_overrides_for_block(course.id, unit.location, True)
+
+                # Transform the tuple data (username, full_name, email, location, due_date) for block-specific query
+                extension_data = []
+                for username, fullname, email, location, due_date in query_data:
+                    # Apply email_or_username filter if specified
+                    if email_or_username_filter and email_or_username_filter.lower() not in username.lower():
+                        continue
+
+                    unit_title = title_or_url(unit)
+                    extension_data.append({
+                        'username': username,
+                        'full_name': fullname,
+                        'email': email,
+                        'unit_title': unit_title,
+                        'unit_location': str(location),
+                        'extended_due_date': due_date,
+                    })
+
+            except (InvalidKeyError, Exception):
+                # If block_id is invalid, return empty list
+                return []
+        else:
+            # Use the course-wide logic from get_overrides_for_course
+            query_data = edx_when_api.get_overrides_for_course(course.id)
+
+            # Transform the tuple data into dictionaries for serialization
+            extension_data = []
+            for username, fullname, email, location, due_date in query_data:
+                # Filter by unit if location not in units with due dates
+                if location not in units_dict:
+                    continue
+
+                # Apply email_or_username filter if specified
+                if email_or_username_filter:
+                    email_or_username_filter_lower = email_or_username_filter.lower()
+                    if (email_or_username_filter_lower not in username.lower() and
+                        email_or_username_filter_lower != email.lower()):
+                        continue
+
+                unit_title = title_or_url(units_dict[location])
+                extension_data.append({
+                    'username': username,
+                    'full_name': fullname,
+                    'email': email,
+                    'unit_title': unit_title,
+                    'unit_location': str(location),
+                    'extended_due_date': due_date,
+                })
+
+        # Sort by username and unit title for consistent ordering
+        extension_data.sort(key=lambda x: (x['username'], x['unit_title']))
+
+        return extension_data
+
+    def list(self, request, *args, **kwargs):
+        """
+        Override list to work with our dictionary-based data structure.
+        """
+        queryset = self.get_queryset()
+
+        page = self.paginate_queryset(queryset)
+        if page is not None:
+            serializer = self.get_serializer(page, many=True)
+            return self.get_paginated_response(serializer.data)
+
+        serializer = self.get_serializer(queryset, many=True)
+        return Response(serializer.data)
diff --git a/lms/djangoapps/instructor/views/serializers_v2.py b/lms/djangoapps/instructor/views/serializers_v2.py
index e504867d2af9..9e06dd0cb01f 100644
--- a/lms/djangoapps/instructor/views/serializers_v2.py
+++ b/lms/djangoapps/instructor/views/serializers_v2.py
@@ -416,3 +416,30 @@ def validate_due_datetime(self, value):
             raise serializers.ValidationError(
                 _('The extension due date and time format is incorrect')
             ) from exc
+
+
+class UnitExtensionSerializer(serializers.Serializer):
+    """
+    Serializer for unit extension data.
+
+    This serializer formats the data returned by get_overrides_for_course
+    for the paginated list API endpoint.
+    """
+    username = serializers.CharField(
+        help_text="Username of the learner who has the extension"
+    )
+    full_name = serializers.CharField(
+        help_text="Full name of the learner"
+    )
+    email = serializers.EmailField(
+        help_text="Email address of the learner"
+    )
+    unit_title = serializers.CharField(
+        help_text="Display name or URL of the unit"
+    )
+    unit_location = serializers.CharField(
+        help_text="Block location/ID of the unit"
+    )
+    extended_due_date = serializers.DateTimeField(
+        help_text="The extended due date for the learner"
+    )

From a2e3566ff727c1db7a373f58e9bc1f7b3d383b55 Mon Sep 17 00:00:00 2001
From: javier ontiveros <javier.ontiveros@wgu.edu>
Date: Wed, 17 Dec 2025 15:36:59 -0600
Subject: [PATCH 2/8] chore: fix pylint things

---
 lms/djangoapps/instructor/views/api_v2.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lms/djangoapps/instructor/views/api_v2.py b/lms/djangoapps/instructor/views/api_v2.py
index 43664337e0b4..48284b0b072e 100644
--- a/lms/djangoapps/instructor/views/api_v2.py
+++ b/lms/djangoapps/instructor/views/api_v2.py
@@ -366,7 +366,7 @@ class UnitExtensionsView(ListAPIView):
         GET /api/instructor/v2/courses/{course_id}/unit_extensions?page=2
         GET /api/instructor/v2/courses/{course_id}/unit_extensions?page_size=50
         GET /api/instructor/v2/courses/{course_id}/unit_extensions?email_or_username=john
-        GET /api/instructor/v2/courses/{course_id}/unit_extensions?block_id=block-v1:org+course+run+type@problem+block@unit1
+        GET /api/instructor/v2/courses/{course_id}/unit_extensions?block_id=block-v1:org@problem+block@unit1
 
     **Response Values**
 
@@ -480,7 +480,7 @@ def get_queryset(self):
                         'extended_due_date': due_date,
                     })
 
-            except (InvalidKeyError, Exception):
+            except (InvalidKeyError):
                 # If block_id is invalid, return empty list
                 return []
         else:

From dd4b7eb893e7c94d6a78c01320fbb5666a4c120d Mon Sep 17 00:00:00 2001
From: javier ontiveros <javier.ontiveros@wgu.edu>
Date: Thu, 8 Jan 2026 14:25:30 -0600
Subject: [PATCH 3/8] chore: update to match edx-when comments

---
 lms/djangoapps/instructor/tests/test_api_v2.py | 11 ++++++-----
 lms/djangoapps/instructor/views/api_v2.py      |  9 ++++-----
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/lms/djangoapps/instructor/tests/test_api_v2.py b/lms/djangoapps/instructor/tests/test_api_v2.py
index 5a901fb7e1b0..619388cb53f4 100644
--- a/lms/djangoapps/instructor/tests/test_api_v2.py
+++ b/lms/djangoapps/instructor/tests/test_api_v2.py
@@ -10,6 +10,7 @@
 import ddt
 from django.urls import NoReverseMatch
 from django.urls import reverse
+from opaque_keys import InvalidKeyError
 from pytz import UTC
 from rest_framework import status
 from rest_framework.test import APIClient
@@ -1112,10 +1113,10 @@ def test_filter_by_block_id(self, mock_get_units, mock_find_unit, mock_get_overr
         mock_find_unit.return_value = mock_unit
         mock_get_units.return_value = [mock_unit]
 
-        # Mock block-specific overrides data (username, full_name, due_date)
+        # Mock block-specific overrides data (username, full_name, email, location, due_date)
         extended_date = datetime(2025, 1, 15, 23, 59, 59, tzinfo=UTC)
         mock_get_overrides_block.return_value = [
-            ('student1', 'John Doe', extended_date),
+            ('student1', 'John Doe', 'john@example.com', mock_unit.location, extended_date),
         ]
 
         self.client.force_authenticate(user=self.instructor)
@@ -1135,7 +1136,7 @@ def test_filter_by_invalid_block_id(self, mock_find_unit):
         Test filtering by invalid block_id returns empty list.
         """
         # Make find_unit raise an exception
-        mock_find_unit.side_effect = Exception('Invalid block')
+        mock_find_unit.side_effect = InvalidKeyError('Invalid block', 'invalid-block-id')
 
         self.client.force_authenticate(user=self.instructor)
         params = {'block_id': 'invalid-block-id'}
@@ -1164,8 +1165,8 @@ def test_combined_filters(self, mock_find_unit, mock_get_overrides_block):
         # Mock block-specific overrides data
         extended_date = datetime(2025, 1, 15, 23, 59, 59, tzinfo=UTC)
         mock_get_overrides_block.return_value = [
-            ('student1', 'John Doe', extended_date),
-            ('student2', 'Jane Smith', extended_date),
+            ('student1', 'John Doe', extended_date, 'john@example.com', mock_unit.location),
+            ('student2', 'Jane Smith', extended_date, 'jane@example.com', mock_unit.location),
         ]
 
         self.client.force_authenticate(user=self.instructor)
diff --git a/lms/djangoapps/instructor/views/api_v2.py b/lms/djangoapps/instructor/views/api_v2.py
index 48284b0b072e..651067e8107c 100644
--- a/lms/djangoapps/instructor/views/api_v2.py
+++ b/lms/djangoapps/instructor/views/api_v2.py
@@ -429,7 +429,6 @@ class UnitExtensionsView(ListAPIView):
             404: "The requested course does not exist.",
         },
     )
-
     def get_queryset(self):
         """
         Returns the queryset of unit extensions for the specified course.
@@ -461,11 +460,11 @@ def get_queryset(self):
                 unit = find_unit(course, block_id_filter)
 
                 # Use the block-specific API call for better performance
-                query_data = edx_when_api.get_overrides_for_block(course.id, unit.location, True)
+                query_data = edx_when_api.get_overrides_for_block(course.id, unit.location)
 
-                # Transform the tuple data (username, full_name, email, location, due_date) for block-specific query
+                # Transform the tuple data (username, full_name, due_date, email, location) for block-specific query
                 extension_data = []
-                for username, fullname, email, location, due_date in query_data:
+                for username, fullname, due_date, email, location in query_data:
                     # Apply email_or_username filter if specified
                     if email_or_username_filter and email_or_username_filter.lower() not in username.lower():
                         continue
@@ -498,7 +497,7 @@ def get_queryset(self):
                 if email_or_username_filter:
                     email_or_username_filter_lower = email_or_username_filter.lower()
                     if (email_or_username_filter_lower not in username.lower() and
-                        email_or_username_filter_lower != email.lower()):
+                            email_or_username_filter_lower != email.lower()):
                         continue
 
                 unit_title = title_or_url(units_dict[location])

From 43deb2ab33580dddcb26eacc54598df5e12a9590 Mon Sep 17 00:00:00 2001
From: javier ontiveros <javier.ontiveros@wgu.edu>
Date: Fri, 9 Jan 2026 15:26:11 -0600
Subject: [PATCH 4/8] chore: update edx_when version

---
 requirements/edx/base.txt        | 2 +-
 requirements/edx/development.txt | 2 +-
 requirements/edx/doc.txt         | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/requirements/edx/base.txt b/requirements/edx/base.txt
index 13d36c644595..565e7503a29d 100644
--- a/requirements/edx/base.txt
+++ b/requirements/edx/base.txt
@@ -546,7 +546,7 @@ edx-toggles==5.4.1
     #   edxval
     #   event-tracking
     #   ora2
-edx-when==3.0.0
+edx-when==3.1.0
     # via
     #   -r requirements/edx/kernel.in
     #   edx-proctoring
diff --git a/requirements/edx/development.txt b/requirements/edx/development.txt
index 1b23b5b14bb1..a34c499a7ca4 100644
--- a/requirements/edx/development.txt
+++ b/requirements/edx/development.txt
@@ -852,7 +852,7 @@ edx-toggles==5.4.1
     #   edxval
     #   event-tracking
     #   ora2
-edx-when==3.0.0
+edx-when==3.1.0
     # via
     #   -r requirements/edx/doc.txt
     #   -r requirements/edx/testing.txt
diff --git a/requirements/edx/doc.txt b/requirements/edx/doc.txt
index d6dc34a342f2..0d26eab55fcb 100644
--- a/requirements/edx/doc.txt
+++ b/requirements/edx/doc.txt
@@ -636,7 +636,7 @@ edx-toggles==5.4.1
     #   edxval
     #   event-tracking
     #   ora2
-edx-when==3.0.0
+edx-when==3.1.0
     # via
     #   -r requirements/edx/base.txt
     #   edx-proctoring

From 7a98a89ab08217959aed40e254a7b6f9b56800bf Mon Sep 17 00:00:00 2001
From: javier ontiveros <javier.ontiveros@wgu.edu>
Date: Fri, 9 Jan 2026 15:59:25 -0600
Subject: [PATCH 5/8] chore: restore old version before upgrade with make

---
 requirements/edx/base.txt        | 2 +-
 requirements/edx/development.txt | 2 +-
 requirements/edx/doc.txt         | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/requirements/edx/base.txt b/requirements/edx/base.txt
index 565e7503a29d..13d36c644595 100644
--- a/requirements/edx/base.txt
+++ b/requirements/edx/base.txt
@@ -546,7 +546,7 @@ edx-toggles==5.4.1
     #   edxval
     #   event-tracking
     #   ora2
-edx-when==3.1.0
+edx-when==3.0.0
     # via
     #   -r requirements/edx/kernel.in
     #   edx-proctoring
diff --git a/requirements/edx/development.txt b/requirements/edx/development.txt
index a34c499a7ca4..1b23b5b14bb1 100644
--- a/requirements/edx/development.txt
+++ b/requirements/edx/development.txt
@@ -852,7 +852,7 @@ edx-toggles==5.4.1
     #   edxval
     #   event-tracking
     #   ora2
-edx-when==3.1.0
+edx-when==3.0.0
     # via
     #   -r requirements/edx/doc.txt
     #   -r requirements/edx/testing.txt
diff --git a/requirements/edx/doc.txt b/requirements/edx/doc.txt
index 0d26eab55fcb..d6dc34a342f2 100644
--- a/requirements/edx/doc.txt
+++ b/requirements/edx/doc.txt
@@ -636,7 +636,7 @@ edx-toggles==5.4.1
     #   edxval
     #   event-tracking
     #   ora2
-edx-when==3.1.0
+edx-when==3.0.0
     # via
     #   -r requirements/edx/base.txt
     #   edx-proctoring

From 4913b986e05c2f70c760c4114ac1cda8155efd0f Mon Sep 17 00:00:00 2001
From: javier ontiveros <javier.ontiveros@wgu.edu>
Date: Fri, 9 Jan 2026 16:08:18 -0600
Subject: [PATCH 6/8] chore: update with make upgrade-package package=edx-when

---
 requirements/edx/base.txt        | 2 +-
 requirements/edx/development.txt | 2 +-
 requirements/edx/doc.txt         | 2 +-
 requirements/edx/testing.txt     | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/requirements/edx/base.txt b/requirements/edx/base.txt
index 13d36c644595..565e7503a29d 100644
--- a/requirements/edx/base.txt
+++ b/requirements/edx/base.txt
@@ -546,7 +546,7 @@ edx-toggles==5.4.1
     #   edxval
     #   event-tracking
     #   ora2
-edx-when==3.0.0
+edx-when==3.1.0
     # via
     #   -r requirements/edx/kernel.in
     #   edx-proctoring
diff --git a/requirements/edx/development.txt b/requirements/edx/development.txt
index 1b23b5b14bb1..a34c499a7ca4 100644
--- a/requirements/edx/development.txt
+++ b/requirements/edx/development.txt
@@ -852,7 +852,7 @@ edx-toggles==5.4.1
     #   edxval
     #   event-tracking
     #   ora2
-edx-when==3.0.0
+edx-when==3.1.0
     # via
     #   -r requirements/edx/doc.txt
     #   -r requirements/edx/testing.txt
diff --git a/requirements/edx/doc.txt b/requirements/edx/doc.txt
index d6dc34a342f2..0d26eab55fcb 100644
--- a/requirements/edx/doc.txt
+++ b/requirements/edx/doc.txt
@@ -636,7 +636,7 @@ edx-toggles==5.4.1
     #   edxval
     #   event-tracking
     #   ora2
-edx-when==3.0.0
+edx-when==3.1.0
     # via
     #   -r requirements/edx/base.txt
     #   edx-proctoring
diff --git a/requirements/edx/testing.txt b/requirements/edx/testing.txt
index 9ce5c2944f79..b8887f659d92 100644
--- a/requirements/edx/testing.txt
+++ b/requirements/edx/testing.txt
@@ -660,7 +660,7 @@ edx-toggles==5.4.1
     #   edxval
     #   event-tracking
     #   ora2
-edx-when==3.0.0
+edx-when==3.1.0
     # via
     #   -r requirements/edx/base.txt
     #   edx-proctoring

From 55eef0e333c2fefef6f1d30586502536c538467f Mon Sep 17 00:00:00 2001
From: javier ontiveros <javier.ontiveros@wgu.edu>
Date: Mon, 12 Jan 2026 09:24:15 -0600
Subject: [PATCH 7/8] chore: exclude extras from get_overrides_for_block to
 prevent tuple from breaking

---
 lms/djangoapps/instructor/views/tools.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lms/djangoapps/instructor/views/tools.py b/lms/djangoapps/instructor/views/tools.py
index 5a62f705f530..8b32e019db02 100644
--- a/lms/djangoapps/instructor/views/tools.py
+++ b/lms/djangoapps/instructor/views/tools.py
@@ -220,7 +220,7 @@ def dump_block_extensions(course, unit):
     """
     header = [_("Username"), _("Full Name"), _("Extended Due Date")]
     data = []
-    for username, fullname, due_date in api.get_overrides_for_block(course.id, unit.location):
+    for username, fullname, due_date, *unused in api.get_overrides_for_block(course.id, unit.location):
         due_date = due_date.strftime('%Y-%m-%d %H:%M')
         data.append(dict(list(zip(header, (username, fullname, due_date)))))
     data.sort(key=operator.itemgetter(_("Username")))

From 9c95a16296324fd9f05998ed2beda1cb068e5812 Mon Sep 17 00:00:00 2001
From: Daniel Wong <danieleduardo.wongfa@wgu.edu>
Date: Fri, 16 Jan 2026 19:05:16 -0600
Subject: [PATCH 8/8] feat: address review comments

- Adjust tests for more consistent behavior
- Add UnitDueDateExtension as a data interface
- Reduce code duplication
---
 .../instructor/tests/test_api_v2.py           | 242 +++++++++++-------
 lms/djangoapps/instructor/views/api_v2.py     | 177 ++++++-------
 2 files changed, 234 insertions(+), 185 deletions(-)

diff --git a/lms/djangoapps/instructor/tests/test_api_v2.py b/lms/djangoapps/instructor/tests/test_api_v2.py
index 619388cb53f4..0bcd9a5404d0 100644
--- a/lms/djangoapps/instructor/tests/test_api_v2.py
+++ b/lms/djangoapps/instructor/tests/test_api_v2.py
@@ -10,11 +10,13 @@
 import ddt
 from django.urls import NoReverseMatch
 from django.urls import reverse
+from django.utils import timezone
 from opaque_keys import InvalidKeyError
 from pytz import UTC
 from rest_framework import status
 from rest_framework.test import APIClient
 
+from edx_when.api import set_dates_for_course, set_date_for_block
 from common.djangoapps.student.roles import CourseDataResearcherRole, CourseInstructorRole
 from common.djangoapps.student.tests.factories import (
     AdminFactory,
@@ -954,6 +956,27 @@ def setUp(self):
             is_active=True
         )
 
+        date1 = timezone.make_aware(datetime(2019, 3, 22))
+        date2 = timezone.make_aware(datetime(2019, 3, 23))
+        date3 = timezone.make_aware(datetime(2019, 3, 24))
+
+        override1 = timezone.make_aware(datetime(2019, 4, 1))
+        override2 = timezone.make_aware(datetime(2019, 4, 2))
+        override3 = timezone.make_aware(datetime(2019, 4, 3))
+
+        items = [
+            (self.subsection.location, {'due': date1}),
+            (self.vertical.location, {'due': date2}),
+            (self.problem.location, {'due': date3}),
+        ]
+        set_dates_for_course(self.course_key, items)
+
+        set_date_for_block(self.course_key, self.subsection.location, 'due', override1, user=self.instructor)
+        set_date_for_block(self.course_key, self.vertical.location, 'due', override2, user=self.student1)
+        set_date_for_block(self.course_key, self.problem.location, 'due', override3, user=self.student2)
+        # Multiple overrides per user
+        set_date_for_block(self.course_key, self.subsection.location, 'due', override2, user=self.student1)
+
     def _get_url(self, course_id=None):
         """Helper to get the API URL."""
         if course_id is None:
@@ -1012,6 +1035,29 @@ def test_get_unit_extensions_nonexistent_course(self):
 
         self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
 
+    def test_get_unit_extensions_with_no_mockups(self):
+        """
+        Test unit extensions with mocked data.
+        """
+
+        self.client.force_authenticate(user=self.instructor)
+        response = self.client.get(self._get_url())
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        data = response.data
+        results = data['results']
+
+        self.assertEqual(len(results), 2)
+
+        # If there are results, verify the structure
+        extension = results[1]
+        self.assertEqual(extension['username'], 'student1')
+        self.assertIn('Robot', extension['full_name'])
+        self.assertEqual(extension['email'], 'student1@example.com')
+        self.assertEqual(extension['unit_title'], 'Homework 1')
+        self.assertEqual(extension['unit_location'], 'block-v1:edX+TestX+Test_Course+type@sequential+block@Homework_1')
+        self.assertEqual(extension['extended_due_date'], '2019-04-02T00:00:00Z')
+
     @patch('lms.djangoapps.instructor.views.api_v2.edx_when_api.get_overrides_for_course')
     @patch('lms.djangoapps.instructor.views.api_v2.get_units_with_due_date')
     def test_get_unit_extensions_with_data(self, mock_get_units, mock_get_overrides):
@@ -1043,21 +1089,27 @@ def test_get_unit_extensions_with_data(self, mock_get_units, mock_get_overrides)
         data = response.data
         results = data['results']
 
-        self.assertGreaterEqual(len(results), 0)
+        self.assertGreaterEqual(len(results), 1)
 
         # If there are results, verify the structure
-        if results:
-            extension = results[0]
-            expected_fields = [
-                'username', 'full_name', 'email',
-                'unit_title', 'unit_location', 'extended_due_date'
-            ]
-            for field in expected_fields:
-                self.assertIn(field, extension)
+        extension = results[0]
+        self.assertEqual(extension['username'], 'student1')
+        self.assertEqual(extension['full_name'], 'John Doe')
+        self.assertEqual(extension['email'], 'john@example.com')
+        self.assertEqual(extension['unit_title'], 'Homework 1')
+        self.assertEqual(extension['unit_location'], 'block-v1:Test+Course+2024+type@sequential+block@hw1')
+        self.assertEqual(extension['extended_due_date'], extended_date.strftime("%Y-%m-%dT%H:%M:%SZ"))
 
+    @ddt.data(
+        ('student1', True),
+        ('jane@example.com', False),
+        ('STUDENT1', True),  # Test case insensitive
+        ('JANE@EXAMPLE.COM', False),  # Test case insensitive
+    )
+    @ddt.unpack
     @patch('lms.djangoapps.instructor.views.api_v2.edx_when_api.get_overrides_for_course')
     @patch('lms.djangoapps.instructor.views.api_v2.get_units_with_due_date')
-    def test_filter_by_email_or_username(self, mock_get_units, mock_get_overrides):
+    def test_filter_by_email_or_username(self, filter_value, is_username, mock_get_units, mock_get_overrides):
         """
         Test filtering unit extensions by email or username.
         """
@@ -1082,20 +1134,19 @@ def test_filter_by_email_or_username(self, mock_get_units, mock_get_overrides):
         self.client.force_authenticate(user=self.instructor)
 
         # Test filter by username
-        params = {'email_or_username': 'student1'}
-        url = f"{self._get_url()}?{urlencode(params)}"
-        response = self.client.get(url)
+        params = {'email_or_username': filter_value}
+        response = self.client.get(self._get_url(), params)
 
         self.assertEqual(response.status_code, status.HTTP_200_OK)
-        # The filter logic should be called
-        mock_get_overrides.assert_called()
-
-        # Test filter by email
-        params = {'email_or_username': 'jane@example.com'}
-        url = f"{self._get_url()}?{urlencode(params)}"
-        response = self.client.get(url)
+        data = response.data
+        results = data['results']
 
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        for r in results:
+            # Check that the filter value is in the appropriate field
+            if is_username:
+                self.assertIn(filter_value.lower(), r['username'].lower())
+            else:
+                self.assertIn(filter_value.lower(), r['email'].lower())
 
     @patch('lms.djangoapps.instructor.views.api_v2.edx_when_api.get_overrides_for_block')
     @patch('lms.djangoapps.instructor.views.api_v2.find_unit')
@@ -1116,19 +1167,28 @@ def test_filter_by_block_id(self, mock_get_units, mock_find_unit, mock_get_overr
         # Mock block-specific overrides data (username, full_name, email, location, due_date)
         extended_date = datetime(2025, 1, 15, 23, 59, 59, tzinfo=UTC)
         mock_get_overrides_block.return_value = [
-            ('student1', 'John Doe', 'john@example.com', mock_unit.location, extended_date),
+            ('student1', 'John Doe', extended_date, 'john@example.com', mock_unit.location),
         ]
 
         self.client.force_authenticate(user=self.instructor)
         params = {'block_id': 'block-v1:Test+Course+2024+type@sequential+block@hw1'}
-        url = f"{self._get_url()}?{urlencode(params)}"
-        response = self.client.get(url)
+        response = self.client.get(self._get_url(), params)
 
         self.assertEqual(response.status_code, status.HTTP_200_OK)
 
-        # Verify the block-specific API was called
-        mock_get_overrides_block.assert_called_once()
-        mock_find_unit.assert_called_once()
+        data = response.data
+        results = data['results']
+
+        self.assertEqual(data['count'], 1)
+        self.assertEqual(len(results), 1)
+
+        data = results[0]
+        self.assertEqual(data['username'], 'student1')
+        self.assertEqual(data['full_name'], 'John Doe')
+        self.assertEqual(data['email'], 'john@example.com')
+        self.assertEqual(data['unit_title'], 'Homework 1')
+        self.assertEqual(data['unit_location'], 'block-v1:Test+Course+2024+type@sequential+block@hw1')
+        self.assertEqual(data['extended_due_date'], extended_date.strftime("%Y-%m-%dT%H:%M:%SZ"))
 
     @patch('lms.djangoapps.instructor.views.api_v2.find_unit')
     def test_filter_by_invalid_block_id(self, mock_find_unit):
@@ -1140,8 +1200,7 @@ def test_filter_by_invalid_block_id(self, mock_find_unit):
 
         self.client.force_authenticate(user=self.instructor)
         params = {'block_id': 'invalid-block-id'}
-        url = f"{self._get_url()}?{urlencode(params)}"
-        response = self.client.get(url)
+        response = self.client.get(self._get_url(), params)
 
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         data = response.data
@@ -1174,24 +1233,53 @@ def test_combined_filters(self, mock_find_unit, mock_get_overrides_block):
             'block_id': 'block-v1:Test+Course+2024+type@sequential+block@hw1',
             'email_or_username': 'student1'
         }
-        url = f"{self._get_url()}?{urlencode(params)}"
-        response = self.client.get(url)
+        response = self.client.get(self._get_url(), params)
 
         self.assertEqual(response.status_code, status.HTTP_200_OK)
-        # Both filters should be applied
-        mock_get_overrides_block.assert_called_once()
-        mock_find_unit.assert_called_once()
 
-    def test_pagination_parameters(self):
+        data = response.data
+        results = data['results']
+
+        self.assertEqual(data['count'], 1)
+        self.assertEqual(len(results), 1)
+
+        data = results[0]
+        # Match only the filtered student1
+        self.assertEqual(data['username'], 'student1')
+        self.assertEqual(data['full_name'], 'John Doe')
+        self.assertEqual(data['email'], 'john@example.com')
+        self.assertEqual(data['unit_title'], 'Homework 1')
+        self.assertEqual(data['unit_location'], 'block-v1:Test+Course+2024+type@sequential+block@hw1')
+        self.assertEqual(data['extended_due_date'], extended_date.strftime("%Y-%m-%dT%H:%M:%SZ"))
+
+    @patch('lms.djangoapps.instructor.views.api_v2.edx_when_api.get_overrides_for_course')
+    @patch('lms.djangoapps.instructor.views.api_v2.get_units_with_due_date')
+    def test_pagination_parameters(self, mock_get_units, mock_get_overrides):
         """
         Test that pagination parameters work correctly.
         """
+        # Mock units with due dates
+        mock_unit = Mock()
+        mock_unit.display_name = 'Homework 1'
+        mock_unit.location = Mock()
+        mock_unit.location.__str__ = Mock(return_value='block-v1:Test+Course+2024+type@sequential+block@hw1')
+        mock_get_units.return_value = [mock_unit]
+
+        # Mock location for dictionary lookup
+        mock_location = Mock()
+        mock_location.__str__ = Mock(return_value='block-v1:Test+Course+2024+type@sequential+block@hw1')
+
+        # Mock course overrides data
+        extended_date = datetime(2025, 1, 15, 23, 59, 59, tzinfo=UTC)
+        mock_get_overrides.return_value = [
+            ('student1', 'John Doe', 'john@example.com', mock_location, extended_date),
+            ('student2', 'Jane Smith', 'jane@example.com', mock_location, extended_date),
+        ]
         self.client.force_authenticate(user=self.instructor)
 
         # Test page parameter
-        params = {'page': '1', 'page_size': '10'}
-        url = f"{self._get_url()}?{urlencode(params)}"
-        response = self.client.get(url)
+        params = {'page': '1', 'page_size': '1'}
+        response = self.client.get(self._get_url(), params)
 
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         data = response.data
@@ -1200,6 +1288,20 @@ def test_pagination_parameters(self):
         self.assertIn('previous', data)
         self.assertIn('results', data)
 
+        self.assertEqual(data['count'], 2)
+        self.assertIsNotNone(data['next'])
+        self.assertIsNone(data['previous'])
+        self.assertEqual(len(data['results']), 1)
+
+        # Test second page
+        params = {'page': '2', 'page_size': '1'}
+        response = self.client.get(self._get_url(), params)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        data = response.data
+        self.assertIsNone(data['next'])
+        self.assertIsNotNone(data['previous'])
+        self.assertEqual(len(data['results']), 1)
+
     @patch('lms.djangoapps.instructor.views.api_v2.edx_when_api.get_overrides_for_course')
     @patch('lms.djangoapps.instructor.views.api_v2.get_units_with_due_date')
     def test_empty_results(self, mock_get_units, mock_get_overrides):
@@ -1248,53 +1350,21 @@ def test_extension_data_structure(self, mock_title_or_url, mock_get_units, mock_
 
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         data = response.data
+        self.assertEqual(data['count'], 1)
 
-        if data['results']:
-            extension = data['results'][0]
+        extension = data['results'][0]
 
-            # Verify all required fields are present
-            required_fields = [
-                'username', 'full_name', 'email',
-                'unit_title', 'unit_location', 'extended_due_date'
-            ]
-            for field in required_fields:
-                self.assertIn(field, extension)
-
-            # Verify data types
-            self.assertIsInstance(extension['username'], str)
-            self.assertIsInstance(extension['full_name'], str)
-            self.assertIsInstance(extension['email'], str)
-            self.assertIsInstance(extension['unit_title'], str)
-            self.assertIsInstance(extension['unit_location'], str)
-
-    def test_response_content_type(self):
-        """
-        Test that the response has the correct content type.
-        """
-        self.client.force_authenticate(user=self.instructor)
-        response = self.client.get(self._get_url())
-
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
-        self.assertEqual(response['content-type'], 'application/json')
-
-    @ddt.data(
-        ('student1',),
-        ('john@example.com',),
-        ('STUDENT1',),  # Test case insensitive
-        ('JOHN@EXAMPLE.COM',),  # Test case insensitive
-    )
-    @ddt.unpack
-    def test_email_or_username_filter_variations(self, filter_value):
-        """
-        Test various formats for email_or_username filter.
-        """
-        self.client.force_authenticate(user=self.instructor)
-        params = {'email_or_username': filter_value}
-        url = f"{self._get_url()}?{urlencode(params)}"
-        response = self.client.get(url)
-
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
-        # Verify the response structure is correct regardless of filter
-        data = response.data
-        self.assertIn('count', data)
-        self.assertIn('results', data)
+        # Verify all required fields are present
+        required_fields = [
+            'username', 'full_name', 'email',
+            'unit_title', 'unit_location', 'extended_due_date'
+        ]
+        for field in required_fields:
+            self.assertIn(field, extension)
+
+        # Verify data types
+        self.assertIsInstance(extension['username'], str)
+        self.assertIsInstance(extension['full_name'], str)
+        self.assertIsInstance(extension['email'], str)
+        self.assertIsInstance(extension['unit_title'], str)
+        self.assertIsInstance(extension['unit_location'], str)
diff --git a/lms/djangoapps/instructor/views/api_v2.py b/lms/djangoapps/instructor/views/api_v2.py
index 651067e8107c..ec177c755b05 100644
--- a/lms/djangoapps/instructor/views/api_v2.py
+++ b/lms/djangoapps/instructor/views/api_v2.py
@@ -7,6 +7,8 @@
 
 import logging
 
+from dataclasses import dataclass
+from typing import Optional, Tuple
 import edx_api_doc_tools as apidocs
 from edx_when import api as edx_when_api
 from opaque_keys import InvalidKeyError
@@ -354,11 +356,47 @@ def get(self, request, course_id):
         return Response(formated_subsections, status=status.HTTP_200_OK)
 
 
+@dataclass(frozen=True)
+class UnitDueDateExtension:
+    """Dataclass representing a unit due date extension for a student."""
+
+    username: str
+    full_name: str
+    email: str
+    unit_title: str
+    unit_location: str
+    extended_due_date: Optional[str]
+
+    @classmethod
+    def from_block_tuple(cls, row: Tuple, unit):
+        username, full_name, due_date, email, location = row
+        unit_title = title_or_url(unit)
+        return cls(
+            username=username,
+            full_name=full_name,
+            email=email,
+            unit_title=unit_title,
+            unit_location=location,
+            extended_due_date=due_date,
+        )
+
+    @classmethod
+    def from_course_tuple(cls, row: Tuple, units_dict: dict):
+        username, full_name, email, location, due_date = row
+        unit_title = title_or_url(units_dict[str(location)])
+        return cls(
+            username=username,
+            full_name=full_name,
+            email=email,
+            unit_title=unit_title,
+            unit_location=location,
+            extended_due_date=due_date,
+        )
+
+
 class UnitExtensionsView(ListAPIView):
     """
-    **Use Cases**
-
-        Retrieve a paginated list of due date extensions for units in a course.
+    Retrieve a paginated list of due date extensions for units in a course.
 
     **Example Requests**
 
@@ -404,127 +442,68 @@ class UnitExtensionsView(ListAPIView):
     permission_name = permissions.VIEW_DASHBOARD
     serializer_class = UnitExtensionSerializer
 
-    @apidocs.schema(
-        parameters=[
-            apidocs.string_parameter(
-                'course_id',
-                apidocs.ParameterLocation.PATH,
-                description="Course key for the course.",
-            ),
-            apidocs.string_parameter(
-                'email_or_username',
-                apidocs.ParameterLocation.QUERY,
-                description="Optional: Filter by username or email address.",
-            ),
-            apidocs.string_parameter(
-                'block_id',
-                apidocs.ParameterLocation.QUERY,
-                description="Optional: Filter by specific unit/subsection location.",
-            ),
-        ],
-        responses={
-            200: UnitExtensionSerializer(many=True),
-            401: "The requesting user is not authenticated.",
-            403: "The requesting user lacks instructor permissions.",
-            404: "The requested course does not exist.",
-        },
-    )
     def get_queryset(self):
         """
         Returns the queryset of unit extensions for the specified course.
 
         This method uses the core logic from get_overrides_for_course to retrieve
-        due date extension data and transforms it into a list of dictionaries
+        due date extension data and transforms it into a list of normalized objects
         that can be paginated and serialized.
 
         Supports filtering by:
         - email_or_username: Filter by username or email address
         - block_id: Filter by specific unit/subsection location
         """
-        course_id = self.kwargs['course_id']
+        course_id = self.kwargs["course_id"]
         course_key = CourseKey.from_string(course_id)
         course = get_course_by_id(course_key)
 
-        # Get query parameters for filtering
-        email_or_username_filter = self.request.query_params.get('email_or_username', None)
-        block_id_filter = self.request.query_params.get('block_id', None)
+        email_or_username_filter = self.request.query_params.get("email_or_username")
+        block_id_filter = self.request.query_params.get("block_id")
 
-        # Get units with due dates for filtering
         units = get_units_with_due_date(course)
-        units_dict = {u.location: u for u in units}
+        units_dict = {str(u.location): u for u in units}
 
-        # If filtering by specific unit, use the block-specific logic
+        # Fetch and normalize overrides
         if block_id_filter:
             try:
-                # Parse the block_id and find the unit
                 unit = find_unit(course, block_id_filter)
-
-                # Use the block-specific API call for better performance
                 query_data = edx_when_api.get_overrides_for_block(course.id, unit.location)
-
-                # Transform the tuple data (username, full_name, due_date, email, location) for block-specific query
-                extension_data = []
-                for username, fullname, due_date, email, location in query_data:
-                    # Apply email_or_username filter if specified
-                    if email_or_username_filter and email_or_username_filter.lower() not in username.lower():
-                        continue
-
-                    unit_title = title_or_url(unit)
-                    extension_data.append({
-                        'username': username,
-                        'full_name': fullname,
-                        'email': email,
-                        'unit_title': unit_title,
-                        'unit_location': str(location),
-                        'extended_due_date': due_date,
-                    })
-
-            except (InvalidKeyError):
+                unit_due_date_extensions = [
+                    UnitDueDateExtension.from_block_tuple(row, unit)
+                    for row in query_data
+                ]
+            except InvalidKeyError:
                 # If block_id is invalid, return empty list
-                return []
+                unit_due_date_extensions = []
         else:
-            # Use the course-wide logic from get_overrides_for_course
             query_data = edx_when_api.get_overrides_for_course(course.id)
+            unit_due_date_extensions = [
+                UnitDueDateExtension.from_course_tuple(row, units_dict)
+                for row in query_data
+                if str(row[3]) in units_dict  # Ensure unit has due date
+            ]
 
-            # Transform the tuple data into dictionaries for serialization
-            extension_data = []
-            for username, fullname, email, location, due_date in query_data:
-                # Filter by unit if location not in units with due dates
-                if location not in units_dict:
+        # Apply filters
+        results = []
+        filter_value = email_or_username_filter.lower() if email_or_username_filter else None
+
+        for unit_due_date_extension in unit_due_date_extensions:
+            # Optional username/email filter
+            if filter_value:
+                if (
+                    filter_value not in unit_due_date_extension.username.lower()
+                    and filter_value not in unit_due_date_extension.email.lower()
+                ):
                     continue
+            results.append(unit_due_date_extension)
 
-                # Apply email_or_username filter if specified
-                if email_or_username_filter:
-                    email_or_username_filter_lower = email_or_username_filter.lower()
-                    if (email_or_username_filter_lower not in username.lower() and
-                            email_or_username_filter_lower != email.lower()):
-                        continue
-
-                unit_title = title_or_url(units_dict[location])
-                extension_data.append({
-                    'username': username,
-                    'full_name': fullname,
-                    'email': email,
-                    'unit_title': unit_title,
-                    'unit_location': str(location),
-                    'extended_due_date': due_date,
-                })
-
-        # Sort by username and unit title for consistent ordering
-        extension_data.sort(key=lambda x: (x['username'], x['unit_title']))
-
-        return extension_data
-
-    def list(self, request, *args, **kwargs):
-        """
-        Override list to work with our dictionary-based data structure.
-        """
-        queryset = self.get_queryset()
-
-        page = self.paginate_queryset(queryset)
-        if page is not None:
-            serializer = self.get_serializer(page, many=True)
-            return self.get_paginated_response(serializer.data)
+        # Sort for consistent ordering
+        results.sort(
+            key=lambda o: (
+                o.username,
+                o.unit_title,
+            )
+        )
 
-        serializer = self.get_serializer(queryset, many=True)
-        return Response(serializer.data)
+        return results