Order child epics in roadmap by configured sort order

Changelog: fixed
EE: true

ee/app/assets/javascripts/roadmap/store/actions.js

@@ -69,12 +69,18 @@ const fetchGroupEpics = (
 
 export const fetchChildrenEpics = (state, { parentItem }) => {
   const { iid, group } = parentItem;
-  const { filterParams, epicsState } = state;
+  const { filterParams, epicsState, sortedBy } = state;
 
   return epicUtils.gqClient
     .query({
       query: epicChildEpics,
-      variables: { iid, fullPath: group?.fullPath, state: epicsState, ...filterParams },
+      variables: {
+        iid,
+        fullPath: group?.fullPath,
+        state: epicsState,
+        sort: sortedBy,
+        ...filterParams,
+      },
     })
     .then(({ data }) => {
       const edges = data?.group?.epic?.children?.edges || [];

ee/spec/frontend/roadmap/store/actions_spec.js

 import MockAdapter from 'axios-mock-adapter';
 import { DATE_RANGES, PRESET_TYPES } from 'ee/roadmap/constants';
 import groupMilestones from 'ee/roadmap/queries/groupMilestones.query.graphql';
+import epicChildEpics from 'ee/roadmap/queries/epicChildEpics.query.graphql';
 import * as actions from 'ee/roadmap/store/actions';
 import * as types from 'ee/roadmap/store/mutation_types';
 import defaultState from 'ee/roadmap/store/state';
@@ -29,6 +30,7 @@ import {
   mockMilestone,
   mockFormattedMilestone,
   mockPageInfo,
+  mockEpic,
 } from '../mock_data';
 
 jest.mock('~/flash');
@@ -75,6 +77,38 @@ describe('Roadmap Vuex Actions', () => {
     });
   });
 
+  describe('fetchChildrenEpics', () => {
+    it('should fetch children epics for provided epic iid along with other parameters', () => {
+      jest.spyOn(epicUtils.gqClient, 'query').mockReturnValue(
+        Promise.resolve({
+          data: mockEpicChildEpicsQueryResponse.data,
+        }),
+      );
+
+      const mockState = {
+        fullPath: 'gitlab-org',
+        sortedBy: mockSortedBy,
+        epicsState: 'opened',
+      };
+
+      return actions
+        .fetchChildrenEpics(mockState, {
+          parentItem: mockEpic,
+        })
+        .then(() => {
+          expect(epicUtils.gqClient.query).toHaveBeenCalledWith({
+            query: epicChildEpics,
+            variables: {
+              iid: mockEpic.iid,
+              fullPath: '/groups/gitlab-org/',
+              sort: mockState.sortedBy,
+              state: mockState.epicsState,
+            },
+          });
+        });
+    });
+  });
+
   describe('receiveEpicsSuccess', () => {
     it('should set formatted epics array and epicId to IDs array in state based on provided epics list', () => {
       return testAction(