Set defaults for PageActionButton options

src/PageActionButton.js

@@ -27,7 +27,11 @@
 import browser from 'webextension-polyfill'
 
 
-export default function PageActionButton({ visible, icon, onClicked }) {
+export default function PageActionButton({
+  visible = tab => true,
+  icon = tab => null,
+  onClicked = tab => {},
+}) {
   async function setIcon(tab) {
     let iconSetting = await icon(tab)
     if (typeof iconSetting === 'string' || iconSetting === null) {

src/background_script.js

@@ -4,7 +4,6 @@ import PageActionButton from './PageActionButton'
 import { toggleEnabled, isEnabled, onEnabledChange } from './perOrigin'
 
 const pageActionButton = PageActionButton({
-  visible: tab => true,
   icon: async tab => (await isEnabled(tab.url)) ? '/icon_enabled.svg' : '/icon_disabled.svg',
-  onClicked: async tab => toggleEnabled(tab.url)
+  onClicked: async tab => toggleEnabled(tab.url),
 })