import net import time fn echo_server(mut c net.UdpConn) { mut count := 0 for { eprintln('> echo_server loop count: $count') mut buf := []u8{len: 100} read, addr := c.read(mut buf) or { continue } eprintln('Server got addr $addr, read: $read | buf: $buf') c.write_to(addr, buf[..read]) or { println('Server: connection dropped') return } count++ // Normally, after responding, the test will end, but there are sometimes cases, // when the echo_server continued looping, printing messages constantly. // The sleep here, is a small precaution against spamming the CI with log messages, // when there are network problems, and it allows easier root cause diagnostic, when // they do happen: time.sleep(1000 * time.millisecond) } } const server_addr = '127.0.0.1:40003' fn echo() ! { mut c := net.dial_udp(server_addr) or { panic('could not net.dial_udp: $err') } defer { c.close() or {} } data := 'Hello from vlib/net!' c.write_string(data) or { panic('could not write_string: $err') } mut buf := []u8{len: 100, init: 0} read, addr := c.read(mut buf) or { panic('could not read: $err') } assert read == data.len println('Got address $addr') // Can't test this here because loopback addresses // are mapped to other addresses // assert addr.str() == '127.0.0.1:30001' for i := 0; i < read; i++ { assert buf[i] == data[i] } println('Got "$buf.bytestr()"') c.close()! } fn test_udp() { mut l := net.listen_udp(server_addr) or { panic('could not listen_udp: $err') } go echo_server(mut l) echo() or { panic('could not echo: $err') } l.close() or {} }