DEV: Drop support for removing all appEvent listeners (#14936)

Also removes "appEventsCache". (and reduces the reported test memory usage by ~33%)

There's no longer any need to remove appEvent listeners in application-instance initializers' `teardown`, as app instances are recreated before each test (in both legacy and ember cli envs)

app/assets/javascripts/discourse/app/initializers/edit-notification-clicks-tracker.js

@@ -4,15 +4,11 @@ export default {
   name: "edit-notification-clicks-tracker",
 
   initialize(container) {
-    this.appEvents = container.lookup("service:app-events");
+    const appEvents = container.lookup("service:app-events");
-    this.appEvents.on("edit-notification:clicked", this, this.handleClick);
+    appEvents.on("edit-notification:clicked", this.handleClick);
   },
 
   handleClick({ topicId, postNumber, revisionNumber }) {
     setLastEditNotificationClick(topicId, postNumber, revisionNumber);
   },
-
-  teardown() {
-    this.appEvents.off("edit-notification:clicked", this, this.handleClick);
-  },
 };

app/assets/javascripts/discourse/app/initializers/opengraph-tag-updater.js

@@ -6,21 +6,17 @@ export default {
   initialize(container) {
     // workaround for Safari on iOS 14.3
     // seems it has started using opengraph tags when sharing
-    this.appEvents = container.lookup("service:app-events");
+    const ogTitle = document.querySelector("meta[property='og:title']");
-    this.ogTitle = document.querySelector("meta[property='og:title']");
+    const ogUrl = document.querySelector("meta[property='og:url']");
-    this.ogUrl = document.querySelector("meta[property='og:url']");
 
-    if (this.ogTitle && this.ogUrl) {
+    if (!ogTitle || !ogUrl) {
-      this.appEvents.on("page:changed", this, this.updateOgAttributes);
+      return;
     }
-  },
 
-  updateOgAttributes(data) {
+    const appEvents = container.lookup("service:app-events");
-    this.ogTitle.setAttribute("content", data.title);
+    appEvents.on("page:changed", ({ title, url }) => {
-    this.ogUrl.setAttribute("content", getAbsoluteURL(data.url));
+      ogTitle.setAttribute("content", title);
-  },
+      ogUrl.setAttribute("content", getAbsoluteURL(url));
-
+    });
-  teardown() {
-    this.appEvents.off("page:changed", this, this.updateOgAttributes);
   },
 };

app/assets/javascripts/discourse/app/pre-initializers/inject-discourse-objects.js

@@ -14,7 +14,7 @@ import User from "discourse/models/user";
 
 const ALL_TARGETS = ["controller", "component", "route", "model", "adapter"];
 
-export function registerObjects(container, app) {
+export function registerObjects(app) {
   if (app.__registeredObjects__) {
     // don't run registrations twice.
     return;
@@ -36,7 +36,7 @@ export default {
   after: "discourse-bootstrap",
 
   initialize(container, app) {
-    registerObjects(container, app);
+    registerObjects(app);
 
     let siteSettings = container.lookup("site-settings:main");
 

app/assets/javascripts/discourse/app/services/app-events.js

@@ -1,24 +1,5 @@
 import Evented from "@ember/object/evented";
 import Service from "@ember/service";
-import deprecated from "discourse-common/lib/deprecated";
-
-let _events = {};
-
-export function clearAppEventsCache(container) {
-  if (container) {
-    const appEvents = container.lookup("service:app-events");
-    Object.keys(_events).forEach((eventKey) => {
-      const event = _events[eventKey];
-      event.forEach((listener) => {
-        if (appEvents.has(eventKey)) {
-          appEvents.off(eventKey, listener.target, listener.fn);
-        }
-      });
-    });
-  }
-
-  _events = {};
-}
 
 export default Service.extend(Evented, {
   init() {
@@ -29,49 +10,4 @@ export default Service.extend(Evented, {
       this.currentUser.appEvents = this;
     }
   },
-
-  on() {
-    if (arguments.length === 2) {
-      let [name, fn] = arguments;
-      let target = {};
-      _events[name] = _events[name] || [];
-      _events[name].push({ target, fn });
-
-      this._super(name, target, fn);
-    } else if (arguments.length === 3) {
-      let [name, target, fn] = arguments;
-      _events[name] = _events[name] || [];
-      _events[name].push({ target, fn });
-
-      this._super(...arguments);
-    }
-    return this;
-  },
-
-  off() {
-    let name = arguments[0];
-    let fn = arguments[2];
-
-    if (_events[name]) {
-      if (arguments.length === 1) {
-        deprecated(
-          "Removing all event listeners at once is deprecated, please remove each listener individually."
-        );
-
-        _events[name].forEach((ref) => {
-          this._super(name, ref.target, ref.fn);
-        });
-        delete _events[name];
-      } else if (arguments.length === 3) {
-        this._super(...arguments);
-
-        _events[name] = _events[name].filter((e) => e.fn !== fn);
-        if (_events[name].length === 0) {
-          delete _events[name];
-        }
-      }
-    }
-
-    return this;
-  },
 });

app/assets/javascripts/discourse/tests/helpers/qunit-helpers.js

@@ -302,15 +302,12 @@ export function acceptance(name, optionsOrCallback) {
       resetLastEditNotificationClick();
       clearAuthMethods();
 
-      app._runInitializer("instanceInitializers", (initName, initializer) => {
+      app._runInitializer("instanceInitializers", (_, initializer) => {
-        if (initializer && initializer.teardown) {
+        initializer.teardown?.();
-          initializer.teardown(this.container);
-        }
       });
-      app._runInitializer("initializers", (initName, initializer) => {
+
-        if (initializer && initializer.teardown) {
+      app._runInitializer("initializers", (_, initializer) => {
-          initializer.teardown(this.container);
+        initializer.teardown?.(this.container);
-        }
       });
 
       if (LEGACY_ENV) {

app/assets/javascripts/discourse/tests/setup-tests.js

@@ -12,7 +12,7 @@ import {
   currentSettings,
   resetSettings,
 } from "discourse/tests/helpers/site-settings";
-import { getOwner, setDefaultOwner } from "discourse-common/lib/get-owner";
+import { setDefaultOwner } from "discourse-common/lib/get-owner";
 import { setApplication, setResolver } from "@ember/test-helpers";
 import { setupS3CDN, setupURL } from "discourse-common/lib/get-url";
 import Application from "../app";
@@ -25,7 +25,6 @@ import Session from "discourse/models/session";
 import User from "discourse/models/user";
 import bootbox from "bootbox";
 import { buildResolver } from "discourse-common/resolver";
-import { clearAppEventsCache } from "discourse/services/app-events";
 import { createHelperContext } from "discourse-common/lib/helpers";
 import deprecated from "discourse-common/lib/deprecated";
 import { flushMap } from "discourse/models/store";
@@ -84,7 +83,7 @@ function createApplication(config, settings) {
   }
 
   app.SiteSettings = settings;
-  registerObjects(container, app);
+  registerObjects(app);
   return app;
 }
 
@@ -315,13 +314,6 @@ function setupTestsCommon(application, container, config) {
     $(".modal-backdrop").remove();
     flushMap();
 
-    if (isLegacyEmber()) {
-      // ensures any event not removed is not leaking between tests
-      // most likely in initializers, other places (controller, component...)
-      // should be fixed in code
-      clearAppEventsCache(getOwner(this));
-    }
-
     MessageBus.unsubscribe("*");
     server = null;
   });