Keep better track of vital streams. Add monkey.

lib/util/devutil.js

@@ -40,6 +40,23 @@ devutil.ensureUnusedPort = function(adb, serial, port) {
     })
 }
 
+devutil.waitForPort = function(adb, serial, port) {
+  function closedError(err) {
+    return err.message === 'closed'
+  }
+  return adb.openTcpAsync(serial, port)
+    .then(function(conn) {
+      conn.end()
+      return port
+    })
+    .catch(closedError, function(err) {
+      return Promise.delay(100)
+        .then(function() {
+          return devutil.waitForPort(adb, serial, port)
+        })
+    })
+}
+
 devutil.killProcsByComm = function(adb, serial, comm, bin) {
   return adb.shellAsync(serial, ['ps', comm])
     .then(function(out) {

lib/util/vitals.js

@@ -0,0 +1,24 @@
+var events = require('events')
+var util = require('util')
+
+function Vitals() {
+  events.EventEmitter.call(this)
+}
+
+util.inherits(Vitals, events.EventEmitter)
+
+Vitals.prototype.register = function(name, stream) {
+  var that = this
+
+  stream.on('end', function() {
+    that.emit('end', name)
+  })
+
+  stream.on('error', function(err) {
+    that.emit('error', name, err)
+  })
+
+  return stream
+}
+
+module.exports = Vitals