await-first

Wait the first event in a set of event pairs, then clean up after itself.

Install

$ npm install await-first --save

Example

• awaitFirst(ee, events)

const EventEmitter = require('events');
const awaitFirst = require('await-first');

async function waitMessageOrClose(ee) {
  const o = await awaitFirst(ee, [ 'message', 'close' ]);

  switch (o.event) {
    case 'message':
      const msg = o.args[0]; // [ 'hello world' ]
      console.log('new message =>', msg);
      break;
    case 'close':
      console.log('closed');
      break;
  }
}

const ee = new EventEmitter();
waitMessageOrClose(ee);

setTimeout(() => {
  ee.emit('message', 'hello world');
}, 1000);

• obj.awaitFirst(events)

const net = require('net');
const awaitFirst = require('await-first');

async function connect() {
  const socket = net.connect(8080, '127.0.0.1');
  socket.awaitFirst = awaitFirst;

  try {
    // wait `connect` or `error` event
    await socket.awaitFirst([ 'connect', 'error' ]);
  } catch (err) {
    console.log(err);
  }
  // ...
}

connect();