prepend-listener
v0.0.0 event-emitter eventemitter prepend
prepend-listener
Add a listener to an EventEmitter before existing listeners.
Synopsis
// being required from node_modules/markdown-code-blocks
var prepend = require('./')
var test = require('tape')
var EventEmitter = require('events').EventEmitter
test('prependListener', function (t) {
t.plan(3)
var ee = new EventEmitter
, originalFired = false
, prependedFired = false
ee.on('event', function second () {
t.ok(prependedFired, "prepended listener has fired")
originalFired = true
})
prepend(ee, 'event', function first () {
t.ok(!originalFired, "original listener has not fired")
prependedFired = true
})
ee.emit('event')
t.ok(prependedFired && originalFired, "both listeners fired")
})
License
MIT
npm i prepend-listener
Metadata
- MIT
- Whatever
- Stephen Sugden
- released 12/26/2013