Use action const for message passing

Author: anthonyec

src/background/index.js

@@ -1,13 +1,18 @@
+import { CREATE_BOOKMARK } from '../content/show_button_inside_element';
 import createIconRenderer from './icon_renderer';
 
 const renderIcon = createIconRenderer();
 
 setInterval(renderIcon, 1000);
 renderIcon();
 
-chrome.runtime.onMessage.addListener((message) => {
-  chrome.bookmarks.create({
-    title: message.payload.title,
-    url: message.payload.url
-  });
-});
+chrome.runtime.onMessage.addListener(
+  (message = { action: null, payload: null }) => {
+    if (message.action === CREATE_BOOKMARK) {
+      chrome.bookmarks.create({
+        title: message.payload.title,
+        url: message.payload.url
+      });
+    }
+  }
+);

src/content/show_button_inside_element.js

@@ -7,6 +7,8 @@ const CONTAINER_CLASS_NAME = 'powerlet-button';
 const MANAGE_BUTTON_CLASS_NAME = 'manage-button';
 const LABEL_CLASS_NAME = 'add-remove-button__label';
 
+export const CREATE_BOOKMARK = 'CREATE_BOOKMARK';
+
 export function showButtonInsideElement(target, title, code) {
   const shadow = createShadowDomInside(target);
   const style = document.createElement('style');
@@ -118,7 +120,7 @@ export function showButtonInsideElement(target, title, code) {
 
     try {
       chrome.runtime.sendMessage({
-        action: 'create_bookmark',
+        action: 'CREATE_BOOKMARK',
         payload: {
           title: title.trim(),
           url: code.trim()