diff --git a/js/src/common/extend.js b/js/src/common/extend.js
index 7c8694f87..5a29411c6 100644
--- a/js/src/common/extend.js
+++ b/js/src/common/extend.js
@@ -9,27 +9,36 @@
  * Care should be taken to extend the correct object – in most cases, a class'
  * prototype will be the desired target of extension, not the class itself.
  *
- * @example
+ * @example <caption>Example usage of extending one method.</caption>
  * extend(Discussion.prototype, 'badges', function(badges) {
  *   // do something with `badges`
  * });
  *
- * @param {Object} object The object that owns the method
- * @param {String} method The name of the method to extend
+ * @example <caption>Example usage of extending multiple methods.</caption>
+ * extend(IndexPage.prototype, ['oncreate', 'onupdate'], function(vnode) {
+ *   // something that needs to be run on creation and update
+ * });
+ *
+ * @param {object} object The object that owns the method
+ * @param {string|string[]} methods The name or names of the method(s) to extend
  * @param {function} callback A callback which mutates the method's output
  */
-export function extend(object, method, callback) {
-  const original = object[method];
+export function extend(object, methods, callback) {
+  const allMethods = Array.isArray(methods) ? methods : [methods];
 
-  object[method] = function (...args) {
-    const value = original ? original.apply(this, args) : undefined;
+  allMethods.forEach((method) => {
+    const original = object[method];
 
-    callback.apply(this, [value].concat(args));
+    object[method] = function (...args) {
+      const value = original ? original.apply(this, args) : undefined;
 
-    return value;
-  };
+      callback.apply(this, [value].concat(args));
 
-  Object.assign(object[method], original);
+      return value;
+    };
+
+    Object.assign(object[method], original);
+  });
 }
 
 /**
@@ -37,29 +46,38 @@ export function extend(object, method, callback) {
  * new function will be run every time the object's method is called.
  *
  * The replacement function accepts the original method as its first argument,
- * which is like a call to 'super'. Any arguments passed to the original method
+ * which is like a call to `super`. Any arguments passed to the original method
  * are also passed to the replacement.
  *
  * Care should be taken to extend the correct object – in most cases, a class'
  * prototype will be the desired target of extension, not the class itself.
  *
- * @example
+ * @example <caption>Example usage of overriding one method.</caption>
  * override(Discussion.prototype, 'badges', function(original) {
  *   const badges = original();
  *   // do something with badges
  *   return badges;
  * });
  *
- * @param {Object} object The object that owns the method
- * @param {String} method The name of the method to override
+ * @example <caption>Example usage of overriding multiple methods.</caption>
+ * extend(Discussion.prototype, ['oncreate', 'onupdate'], function(original, vnode) {
+ *   // something that needs to be run on creation and update
+ * });
+ *
+ * @param {object} object The object that owns the method
+ * @param {string|string[]} method The name or names of the method(s) to override
  * @param {function} newMethod The method to replace it with
  */
-export function override(object, method, newMethod) {
-  const original = object[method];
+export function override(object, methods, newMethod) {
+  const allMethods = Array.isArray(methods) ? methods : [methods];
 
-  object[method] = function (...args) {
-    return newMethod.apply(this, [original.bind(this)].concat(args));
-  };
+  allMethods.forEach((method) => {
+    const original = object[method];
 
-  Object.assign(object[method], original);
+    object[method] = function (...args) {
+      return newMethod.apply(this, [original.bind(this)].concat(args));
+    };
+
+    Object.assign(object[method], original);
+  });
 }