feat: support timeout

Author: hongcai.dhc

index.js

@@ -1,13 +1,17 @@
 'use strict'
 
-module.exports = function(emitter, event) {
+module.exports = function(emitter, event, timeout) {
   if (typeof emitter === 'string') {
+    timeout = event
     event = emitter
     emitter = this
   }
 
   return new Promise((resolve, reject) => {
     const done = event === 'error' ? reject : resolve
+    if (timeout) {
+      setTimeout(reject, timeout, new Error('timeout'))
+    }
     emitter.once(event, done)
   })
 }

test/index.test.js

@@ -14,6 +14,21 @@ it('await event', () => {
   })
 })
 
+it('await event with timeout', () => {
+  return co(function* () {
+    const e = new EventEmitter()
+    e.await = awaitEvent
+    try {
+      yield e.await('data', 1000)
+    } catch (e) {
+      if (e.message === 'timeout') {
+        return
+      }
+    }
+    throw new Error('boom')
+  })
+})
+
 it('await error', done => {
   co(function* () {
     const e = new EventEmitter()