From a7445011a9c7c3c84592a36eaec939c4a9b59aa0 Mon Sep 17 00:00:00 2001
From: eight <eight04@gmail.com>
Date: Mon, 9 Sep 2019 12:40:07 +0800
Subject: [PATCH] Enhance: faster msg.sendBg (#774)

---
 js/msg.js | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/js/msg.js b/js/msg.js
index 37d87a12..5bbef7a4 100644
--- a/js/msg.js
+++ b/js/msg.js
@@ -41,11 +41,19 @@ const msg = (() => {
     if (isBg) {
       return Promise.resolve(window);
     }
-    if (!chrome.runtime.getBackgroundPage) {
-      return Promise.resolve();
+    // try using extension.getBackgroundPage because runtime.getBackgroundPage is too slow
+    // https://github.com/openstyles/stylus/issues/771
+    if (chrome.extension.getBackgroundPage) {
+      const bg = chrome.extension.getBackgroundPage();
+      if (bg && bg.document && bg.document.readyState !== 'loading') {
+        return Promise.resolve(bg);
+      }
     }
-    return promisify(chrome.runtime.getBackgroundPage.bind(chrome.runtime))()
-      .catch(() => null);
+    if (chrome.runtime.getBackgroundPage) {
+      return promisify(chrome.runtime.getBackgroundPage.bind(chrome.runtime))()
+        .catch(() => null);
+    }
+    return Promise.resolve(null);
   }
 
   function send(data, target = 'extension') {