feat: add AccountSettingsReadOnlyFieldsRequested filter (#334)

* feat: add AccountSettingsReadOnlyFieldsRequested filter

ENT-11510

* fix: update ref to openedx-platform.

* fix: PR requests

* fix: fixing the docstring

---------

Co-authored-by: Kira Miller <31229189+kiram15@users.noreply.github.com>

Author: pwnage101

openedx_filters/learning/filters.py

@@ -1445,3 +1445,43 @@ def run_filter(cls, schedules: QuerySet) -> QuerySet | None:
         """
         data = super().run_pipeline(schedules=schedules)
         return data.get("schedules")
+
+
+class AccountSettingsReadOnlyFieldsRequested(OpenEdxPublicFilter):
+    """
+    Filter used to expand the set of read-only fields on the account settings API.
+
+    Purpose:
+        This filter is triggered when the account settings API validates which fields
+        may be updated for a given user. Pipeline steps may add field names to
+        ``readonly_fields`` to mark those fields as read-only for the requesting user.
+
+    Filter Type:
+        org.openedx.learning.account.settings.read_only_fields.requested.v1
+
+    Trigger:
+        - Repository: openedx/openedx-platform
+        - Path: openedx/core/djangoapps/user_api/accounts/api.py
+        - Function or Method: _validate_read_only_fields
+    """
+
+    filter_type = "org.openedx.learning.account.settings.read_only_fields.requested.v1"
+
+    @classmethod
+    def run_filter(cls, readonly_fields: set, user: Any) -> tuple[Any, Any]:
+        """
+        Process the readonly_fields set using the configured pipeline steps.
+
+        Arguments:
+            readonly_fields (set): the set of field names the caller considers read-only.
+                Pipeline steps add field names to this set to mark additional fields as
+                read-only.
+            user (User): the Django User whose account settings are being updated.
+
+        Returns:
+            tuple[Any | Any]:
+                Any: the (possibly expanded) set of read-only field names.
+                Any: the Django User object.
+        """
+        data = super().run_pipeline(readonly_fields=readonly_fields, user=user)
+        return (data.get("readonly_fields"), data.get("user"))

openedx_filters/learning/tests/test_filters.py

@@ -8,6 +8,7 @@
 from django.test import TestCase
 
 from openedx_filters.learning.filters import (
+    AccountSettingsReadOnlyFieldsRequested,
     AccountSettingsRenderStarted,
     CertificateCreationRequested,
     CertificateRenderStarted,
@@ -801,3 +802,29 @@ def test_schedule_requested(self):
         result = ScheduleQuerySetRequested.run_filter(schedules)
 
         self.assertEqual(schedules, result)
+
+
+class TestAccountSettingsReadOnlyFieldsRequestedFilter(TestCase):
+    """
+    Tests for the AccountSettingsReadOnlyFieldsRequested filter.
+    """
+
+    def test_run_filter_returns_inputs_unchanged_when_no_pipeline(self):
+        """
+        When no pipeline steps are configured, run_filter returns the original inputs unchanged.
+        """
+        readonly_fields = {"username"}
+        user = Mock()
+
+        result_fields, result_user = AccountSettingsReadOnlyFieldsRequested.run_filter(
+            readonly_fields=readonly_fields, user=user
+        )
+
+        self.assertEqual(result_fields, readonly_fields)
+        self.assertEqual(result_user, user)
+
+    def test_filter_type(self):
+        self.assertEqual(
+            AccountSettingsReadOnlyFieldsRequested.filter_type,
+            "org.openedx.learning.account.settings.read_only_fields.requested.v1",
+        )