composed.js

let ctrl = this,
  listResource = resource(( ) => `/api/list/${ctrl.listId()}`, { scope: $scope }),
  followedByUserResource = resource( ( ) => `/api/user/following`, { scope: $scope }),
  listUsersReducer =
    composedReducer(listResource, followedByUserResource, ( ) => ctrl.query)
      .reduce(( list, followed, query ) => {
        
        return list.users.filter(
            user => user.username.includes(query);
        )
          .map( user => {
            return assign(
              {},
              user,
              { followed_by_user: followed.includes(user.id) }
            );
          });
        
      });

ctrl.query = ''; // via ngModel

ctrl.getVisibleUsers = ( ) => visibleUsers.data;