browser: add support for down event

README.md

@@ -116,6 +116,10 @@ Options are the same as given in the `browser.find` function.
 
 Emitted every time a new service is found that matches the browser.
 
+#### `Event: down`
+
+Emitted every time an existing service emmits a goodbye message.
+
 #### `browser.services`
 
 An array of services known by the browser to be online.

lib/browser.js

@@ -44,6 +44,8 @@ Browser.prototype.start = function () {
  var self = this
 
  this._onresponse = function (packet) {
+ goodbyes(self._name, packet).forEach(self._removeService.bind(self))
+
  var matches = buildServicesFor(self._name, packet)
  if (matches.length === 0) return
 
@@ -70,6 +72,31 @@ Browser.prototype._addService = function (service) {
  this.emit('up', service)
 }
 
+Browser.prototype._removeService = function (fqdn) {
+ var service, index
+ this.services.some(function (s, i) {
+ if (s.fqdn === fqdn) {
+ service = s
+ index = i
+ return true
+ }
+ })
+ if (!service) return
+ this.services.splice(index, 1)
+ this._serviceMap[fqdn] = false
+ this.emit('down', service)
+}
+
+function goodbyes (name, packet) {
+ return packet.answers.concat(packet.additionals)
+ .filter(function (rr) {
+ return rr.name === name && rr.type === 'PTR' && rr.ttl === 0
+ })
+ .map(function (rr) {
+ return rr.data
+ })
+}
+
 function buildServicesFor (name, packet) {
  var records = packet.answers.concat(packet.additionals).filter(function (rr) {
  return rr.ttl > 0 // ignore goodbye messages

test/bonjour.js

@@ -88,6 +88,25 @@ test('bonjour.find', function (bonjour, t) {
  bonjour.publish({ name: 'Baz', type: 'test', port: 3000, txt: { foo: 'bar' } }).on('up', next())
 })
 
+test('bonjour.find - down event', function (bonjour, t) {
+ var service = bonjour.publish({ name: 'Foo Bar', type: 'test', port: 3000 })
+
+ service.on('up', function () {
+ var browser = bonjour.find({ type: 'test' })
+
+ browser.on('up', function (s) {
+ t.equal(s.name, 'Foo Bar')
+ service.stop()
+ })
+
+ browser.on('down', function (s) {
+ t.equal(s.name, 'Foo Bar')
+ bonjour.destroy()
+ t.end()
+ })
+ })
+})
+
 test('bonjour.findOne - callback', function (bonjour, t) {
  var next = afterAll(function () {
  bonjour.findOne({ type: 'test' }, function (s) {