Apply PR review changes

Author: josemarluedke

addon/components/stripe-element.js

@@ -70,24 +70,15 @@ export default Component.extend({
     let stripeElement = get(this, 'stripeElement');
 
     stripeElement.on('ready', (event) => {
-      if (this.isDestroying || this.isDestroyed) {
-        return;
-      }
-      this.sendAction('ready', stripeElement, event);
+      this._invokeAction('ready', stripeElement, event)
     });
 
     stripeElement.on('blur', (event) => {
-      if (this.isDestroying || this.isDestroyed) {
-        return;
-      }
-      this.sendAction('blur', stripeElement, event)
+      this._invokeAction('blur', stripeElement, event)
     });
 
     stripeElement.on('focus', (event) => {
-      if (this.isDestroying || this.isDestroyed) {
-        return;
-      }
-      this.sendAction('focus', stripeElement, event)
+      this._invokeAction('focus', stripeElement, event)
     });
 
     stripeElement.on('change', (...args) => {
@@ -99,15 +90,25 @@ export default Component.extend({
       this.change(stripeElement, ...args);
 
       if (complete) {
-        this.complete(stripeElement);
+        this._invokeAction('complete', stripeElement)
       } else if (stripeError) {
-        this.error(stripeError);
+        this._invokeAction('error', stripeError)
       }
 
       set(this, 'stripeError', stripeError);
     });
   },
 
+  _invokeAction(method, ...args) {
+    if (this.isDestroying || this.isDestroyed) {
+      return;
+    }
+
+    if (typeof this[method] === 'function') {
+      this[method](...args)
+    }
+  },
+
   ready() { },
   blur() { },
   focus() { },