REFACTOR: We can reuse `getOwner` for some container stuff

app/assets/javascripts/discourse-common/addon/lib/get-owner.js

@@ -5,7 +5,7 @@ let _default = {};
 
 export function getOwner(obj) {
   if (emberGetOwner) {
-    return emberGetOwner(obj) || emberGetOwner(_default);
+    return emberGetOwner(obj || _default) || emberGetOwner(_default);
   }
 
   return obj.container;

app/assets/javascripts/discourse/app/lib/plugin-api.js

@@ -59,6 +59,7 @@ import { on } from "@ember/object/evented";
 import { addQuickAccessProfileItem } from "discourse/widgets/quick-access-profile";
 import KeyboardShortcuts from "discourse/lib/keyboard-shortcuts";
 import { addFeaturedLinkMetaDecorator } from "discourse/lib/render-topic-featured-link";
+import { getOwner } from "discourse-common/lib/get-owner";
 
 // If you add any methods to the API ensure you bump up this number
 const PLUGIN_API_VERSION = "0.10.2";
@@ -1200,17 +1201,11 @@ function cmpVersions(a, b) {
   return segmentsA.length - segmentsB.length;
 }
 
-let _container;
-
-export function setPluginContainer(container) {
-  _container = container;
-}
-
 function getPluginApi(version) {
   version = version.toString();
   if (cmpVersions(version, PLUGIN_API_VERSION) <= 0) {
     if (!_pluginv01) {
-      _pluginv01 = new PluginApi(version, _container);
+      _pluginv01 = new PluginApi(version, getOwner(this));
     }
 
     // We are recycling the compatible object, but let's update to the higher version
@@ -1273,5 +1268,4 @@ function decorate(klass, evt, cb, id) {
 
 export function resetPluginApi() {
   _pluginv01 = null;
-  _container = null;
 }

app/assets/javascripts/discourse/app/lib/show-modal.js

@@ -1,17 +1,15 @@
 import I18n from "I18n";
 import { dasherize } from "@ember/string";
-
-let _container;
-export function setModalContainer(container) {
-  _container = container;
-}
+import { getOwner } from "discourse-common/lib/get-owner";
 
 export default function(name, opts) {
   opts = opts || {};
 
+  let container = getOwner(this);
+
   // We use the container here because modals are like singletons
   // in Discourse. Only one can be shown with a particular state.
-  const route = _container.lookup("route:application");
+  const route = container.lookup("route:application");
   const modalController = route.controllerFor("modal");
 
   modalController.set(
@@ -22,7 +20,7 @@ export default function(name, opts) {
   const controllerName = opts.admin ? `modals/${name}` : name;
   modalController.set("name", controllerName);
 
-  let controller = _container.lookup("controller:" + controllerName);
+  let controller = container.lookup("controller:" + controllerName);
   const templateName = opts.templateName || dasherize(name);
 
   const renderArgs = { into: "modal", outlet: "modalBody" };
@@ -31,7 +29,7 @@ export default function(name, opts) {
   } else {
     // use a basic controller
     renderArgs.controller = "basic-modal-body";
-    controller = _container.lookup(`controller:${renderArgs.controller}`);
+    controller = container.lookup(`controller:${renderArgs.controller}`);
   }
 
   if (opts.addModalBodyView) {

app/assets/javascripts/discourse/app/pre-initializers/discourse-bootstrap.js

@@ -11,9 +11,7 @@ import {
 import { setupURL, setupS3CDN } from "discourse-common/lib/get-url";
 import deprecated from "discourse-common/lib/deprecated";
 import { setIconList } from "discourse-common/lib/icon-library";
-import { setPluginContainer } from "discourse/lib/plugin-api";
 import { setURLContainer } from "discourse/lib/url";
-import { setModalContainer } from "discourse/lib/show-modal";
 import { setDefaultOwner } from "discourse-common/lib/get-owner";
 
 export default {
@@ -21,9 +19,7 @@ export default {
 
   // The very first initializer to run
   initialize(container, app) {
-    setPluginContainer(container);
     setURLContainer(container);
-    setModalContainer(container);
     setDefaultOwner(container);
 
     // Our test environment has its own bootstrap code

test/javascripts/helpers/qunit-helpers.js

@@ -5,7 +5,7 @@ import { later } from "@ember/runloop";
 import sessionFixtures from "fixtures/session-fixtures";
 import HeaderComponent from "discourse/components/site-header";
 import { forceMobile, resetMobile } from "discourse/lib/mobile";
-import { resetPluginApi, setPluginContainer } from "discourse/lib/plugin-api";
+import { resetPluginApi } from "discourse/lib/plugin-api";
 import {
   clearCache as clearOutletCache,
   resetExtraClasses
@@ -29,7 +29,6 @@ import { currentSettings, mergeSettings } from "helpers/site-settings";
 import { getOwner } from "discourse-common/lib/get-owner";
 import { setTopicList } from "discourse/lib/topic-list-tracker";
 import { setURLContainer } from "discourse/lib/url";
-import { setModalContainer } from "discourse/lib/show-modal";
 import { setDefaultOwner } from "discourse-common/lib/get-owner";
 
 export function currentUser() {
@@ -173,9 +172,7 @@ export function acceptance(name, options) {
 
       Discourse.reset();
       this.container = getOwner(this);
-      setPluginContainer(this.container);
       setURLContainer(this.container);
-      setModalContainer(this.container);
       setDefaultOwner(this.container);
 
       if (options.site) {
@@ -211,7 +208,6 @@ export function acceptance(name, options) {
       setTopicList(null);
       _clearSnapshots();
       setURLContainer(null);
-      setModalContainer(null);
       setDefaultOwner(null);
       Discourse._runInitializer(
         "instanceInitializers",