From ee1e00a06b9bfaba9508030623207b3b6d8cbfa0 Mon Sep 17 00:00:00 2001
From: Sebastian Fastner <s.fastner@sebastian-software.de>
Date: Tue, 13 Feb 2018 15:23:50 +0100
Subject: [PATCH] Catch non function listeners

---
 src/index.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/index.js b/src/index.js
index 586e850..f69ce0b 100644
--- a/src/index.js
+++ b/src/index.js
@@ -152,7 +152,12 @@ function interframe(targetWindow, origin = "*", sourceWindow) {
 
       if (listeners.has(message.namespace)) {
         for (const listener of listeners.get(message.namespace).values()) {
-          listener(createMessage(message))
+          // eslint-disable-next-line max-depth
+          if (typeof listener === "function") {
+            listener(createMessage(message))
+          } else if (listener) {
+            console.error("Listener is no function: ", listener) // eslint-disable-line
+          }
         }
       } else {
         if (!outstandingMessages.has(message.namespace)) {