handling hangup on A when outdialing B and creating uas/uac dialogs indepently

gistfile1.txt

const SipError = require('drachtio-srf').SipError;

srf.invite(async(req, res) => {

  let uas, uac, ep;
  try {
    let invite;  // will be used to track invite we send on B leg

    // connect A leg
    const {endpoint, dialog} = await ms.connectCaller(req, res);
    uas = dialog;
    ep = endpoint;

    // temp listener: if A leg hangs up during outdial, cancel B
    uas.on('destroy', () => {
      console.log('caller hung up during outdial');
      if (invite) invite.cancel();
      endpoint.destroy();
    });
    await endpoint.play(`test.wav`);
    endpoint.execute('endless_playback', 'tone_stream://%(400,200,400,425);%(400,2000,400,425)')
      .then(() => console.log(`Finished playing back ringing`));
    uac = await srf.createUAC(`sip:${config.to_number}@${config.outbound_sbc}`,
      {
        localSdp: b_endpoint.local.sdp
      },
      {
        cbRequest: (err, req) => invite = req,
      });
    
    // remove temporary listener during outdial
    uas.removeAllListeners('destroy');

    // since we didnt use createB2BUA, point dialogs to each other
    uas.other = uac;
    uac.other = uas;

    // set the usual handlers
    [uas, uac].forEach((dlg) => {
      dlg.on('destroy', () => {
        dlg.other.destroy();
        endpoint.destroy();
      });
    });
  } catch (err) {
    if (err instanceof SipError) {
      if (err.status === 487) {
        // caller hung up and we canceled B, no need to log
      }
      else {
        console.log(`outdial failed with status ${err.status}`);
      }
    }
    else {
      console.log(`unexpected error: ${err}`);
    }

    // need to explicitly hang up A since we didn't use createB2BUA
    if (uas) uas.destroy();
    if (ep) ep.destroy();
  }
});