From 3f38810d64df1d151c4e73f025b2ff229b5b9c0d Mon Sep 17 00:00:00 2001
From: Emil Bay <github@tixz.dk>
Date: Sat, 4 Jun 2016 15:48:27 +0200
Subject: [PATCH] Fix #37 `rootId` should clear if only `opts` is passed

`rootId` is optional to `start`, but has lower precedence than `opts`. Currently it is not cleared when the value is passed to `opts`
---
 index.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/index.js b/index.js
index ff6b089..c19c0bd 100644
--- a/index.js
+++ b/index.js
@@ -52,7 +52,10 @@ function choo () {
   // start the application
   // (str?, obj?) -> DOMNode
   function start (rootId, opts) {
-    if (!opts) opts = rootId
+    if (!opts) {
+      opts = rootId
+      rootId = null
+    }
     opts = opts || {}
     const name = opts.name || 'choo'
     const initialState = {}