1 files changed, 19 insertions, 0 deletions
diff --git a/src/node/port_picker.js b/src/node/port_picker.js
new file mode 100644
index 0000000000..7b3cfd74ff
--- /dev/null
+++ b/src/node/port_picker.js
@@ -0,0 +1,19 @@
+var net = require('net');
+
+/**
+ * Finds a free port that a server can bind to, in the format
+ * "address:port"
+ * @param {function(string)} cb The callback that should execute when the port
+ *     is available
+ */
+function nextAvailablePort(cb) {
+  var server = net.createServer();
+  server.listen(function() {
+    var address = server.address();
+    server.close(function() {
+      cb(address.address + ':' + address.port.toString());
+    });
+  });
+}
+
+exports.nextAvailablePort = nextAvailablePort;