ui: Adds controller lifecycle `reset` hook (#5056)

ui-v2/app/initializers/controller-lifecycle.js

@@ -0,0 +1,23 @@
+import Route from '@ember/routing/route';
+/**
+ * This initializer is very similar to:
+ * https://github.com/kellyselden/ember-controller-lifecycle
+ *
+ * Why is this included here:
+ * 1. Make sure lifecycle functions are functions, not just truthy.
+ * 2. Right now we don't want a setup function (at least until we are definitely decided that we want one)
+ * This is possibly a very personal opinion so it makes sense to just include this file here.
+ */
+Route.reopen({
+  resetController(controller, exiting, transition) {
+    this._super(...arguments);
+    if (typeof controller.reset === 'function') {
+      controller.reset(exiting);
+    }
+  },
+});
+export function initialize() {}
+
+export default {
+  initialize,
+};

ui-v2/app/mixins/with-listeners.js

@@ -1,3 +1,4 @@
+import Controller from '@ember/controller';
 import Component from '@ember/component';
 import Mixin from '@ember/object/mixin';
 import { inject as service } from '@ember/service';
@@ -8,15 +9,23 @@ export default Mixin.create({
   init: function() {
     this._super(...arguments);
     this._listeners = get(this, 'dom').listeners();
-    let method = 'willDestroy';
+    let teardown = ['willDestroy'];
     if (this instanceof Component) {
-      method = 'willDestroyElement';
+      teardown = ['willDestroyElement'];
+    } else if (this instanceof Controller) {
+      if (typeof this.reset === 'function') {
+        teardown.push('reset');
+      }
     }
-    const destroy = this[method];
-    this[method] = function() {
-      destroy(...arguments);
-      this.removeListeners();
-    };
+    teardown.forEach(method => {
+      const destroy = this[method];
+      this[method] = function() {
+        if (typeof destroy === 'function') {
+          destroy.apply(this, arguments);
+        }
+        this.removeListeners();
+      };
+    });
   },
   listen: function(target, event, handler) {
     return this._listeners.add(...arguments);