From ccfc0b18f3df48d3959078ea0f1903a24bb2e59a Mon Sep 17 00:00:00 2001
From: Artur Arseniev <artur.catch@hotmail.it>
Date: Sun, 23 Aug 2020 22:49:57 +0200
Subject: [PATCH] Fix preview command for tests

---
 src/commands/view/Preview.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/commands/view/Preview.js b/src/commands/view/Preview.js
index fecca5c60..b8693f5f1 100644
--- a/src/commands/view/Preview.js
+++ b/src/commands/view/Preview.js
@@ -22,8 +22,9 @@ export default {
   },
 
   tglEffects(on) {
+    const { em } = this;
     const mthEv = on ? 'on' : 'off';
-    this.em[mthEv]('run:tlb-move:before', this.preventDrag);
+    em && em[mthEv]('run:tlb-move:before', this.preventDrag);
   },
 
   run(editor, sender) {