From 142c7d45f44e6abed2a726d4f142d705ea55291f Mon Sep 17 00:00:00 2001
From: Shin'ya Ueoka <ueokande@i-beam.org>
Date: Tue, 10 Oct 2017 22:11:19 +0900
Subject: [PATCH] fix errors on tabs selection

---
 src/background/tabs.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/background/tabs.js b/src/background/tabs.js
index 166af4d..eed3252 100644
--- a/src/background/tabs.js
+++ b/src/background/tabs.js
@@ -18,12 +18,12 @@ const reopenTab = () => {
 };
 
 const selectAt = (index) => {
-  return browser.tabs.query({ currentWindow: true }, (tabs) => {
+  return browser.tabs.query({ currentWindow: true }).then((tabs) => {
     if (tabs.length < 2) {
       return;
     }
     if (index < 0 || tabs.length <= index) {
-      throw new RangeError(`tab ${index} does not exist`);
+      throw new RangeError(`tab ${index + 1} does not exist`);
     }
     let id = tabs[index].id;
     return browser.tabs.update(id, { active: true });