add tests to check for the close event

test.js

@@ -2,6 +2,7 @@ var tape = require('tape')
 var through = require('through2')
 var concat = require('concat-stream')
 var duplexify = require('./')
+var tcp = require('net')
 
 tape('passthrough', function(t) {
   t.plan(2)
@@ -266,4 +267,66 @@ tape('close', function(t) {
     t.ok(true, 'should forward close')
     t.end()
   })
-})
+})
+
+tape('close is bubbled up on both ends - destroy on listener', function(t) {
+  var listener
+  var counter = 0
+
+  listener = tcp.createServer(function(socket) {
+    var dup = duplexify(socket, socket)
+
+    socket.on('close', count)
+    dup.on('close', count)
+
+    dup.destroy()
+  })
+
+  listener.listen(0)
+
+  var socket = tcp.connect(listener.address())
+  var dup = duplexify(socket, socket)
+
+  socket.on('close', count)
+  dup.on('close', count)
+
+  function count() {
+    console.log('->', counter)
+
+    if (++counter === 4) {
+      return listener.close(t.end)
+    }
+  }
+})
+
+tape('close is bubbled up on both ends - destroy on dialer', function(t) {
+  var listener
+  var counter = 0
+
+  listener = tcp.createServer(function(socket) {
+    var dup = duplexify(socket, socket)
+
+    socket.on('close', count)
+    dup.on('close', count)
+  })
+
+  listener.listen(0)
+
+  var socket = tcp.connect(listener.address())
+  var dup = duplexify(socket, socket)
+
+  socket.on('close', count)
+  dup.on('close', count)
+
+  setTimeout(function () {
+    dup.destroy()
+  }, 100)
+
+  function count() {
+    console.log('->', counter)
+
+    if (++counter === 4) {
+      return listener.close(t.end)
+    }
+  }
+})