iRule to select pool based on client IP and group data list

You don't actually need the explicit default pool chosen if you have oneconnect enabled, if you don't then [LB::server pool] is best way to refer to default pool;-

when HTTP_REQUEST {
    if { [class match [IP::client_addr] equals test_list] }{
        pool test_pool  
    } else {
         You can drop this clause if you have oneconnect enabled as default pool will always be chosen 
        pool [LB::server pool] 
    }    
}