FIX: Flaky JS tests (#12331)

If you were unlucky and tested a mobile raw template before a desktop
raw template, it would keep using the mobile one resulting in failures.

app/assets/javascripts/discourse-common/addon/resolver.js

@@ -3,7 +3,7 @@ import deprecated from "discourse-common/lib/deprecated";
 import { findHelper } from "discourse-common/lib/helpers";
 import { get } from "@ember/object";
 
-const _options = {};
+let _options = {};
 
 export function setResolverOption(name, value) {
   _options[name] = value;
@@ -13,6 +13,10 @@ export function getResolverOption(name) {
   return _options[name];
 }
 
+export function clearResolverOptions() {
+  _options = {};
+}
+
 function parseName(fullName) {
   const nameParts = fullName.split(":");
   const type = nameParts[0];

app/assets/javascripts/discourse/app/models/topic.js

@@ -1,4 +1,4 @@
-import { and, equal, notEmpty, or } from "@ember/object/computed";
+import { alias, and, equal, notEmpty, or } from "@ember/object/computed";
 import { fmt, propertyEqual } from "discourse/lib/computed";
 import ActionSummary from "discourse/models/action-summary";
 import Category from "discourse/models/category";
@@ -58,25 +58,16 @@ const Topic = RestModel.extend({
 
   @discourseComputed("posters.[]")
   lastPoster(posters) {
-    let user;
     if (posters && posters.length > 0) {
       const latest = posters.filter(
         (p) => p.extras && p.extras.indexOf("latest") >= 0
       )[0];
-      user = latest;
+      return latest || posters.firstObject;
     }
-    return user || posters.firstObject;
   },
 
-  @discourseComputed("lastPoster")
-  lastPosterUser(poster) {
-    return poster.user;
-  },
-
-  @discourseComputed("lastPoster")
-  lastPosterGroup(poster) {
-    return poster.primary_group;
-  },
+  lastPosterUser: alias("lastPoster.user"),
+  lastPosterGroup: alias("lastPoster.primary_group"),
 
   @discourseComputed("posters.[]", "participants.[]", "allowed_user_count")
   featuredUsers(posters, participants, allowedUserCount) {

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

@@ -37,6 +37,7 @@ import sessionFixtures from "discourse/tests/fixtures/session-fixtures";
 import { setTopicList } from "discourse/lib/topic-list-tracker";
 import sinon from "sinon";
 import siteFixtures from "discourse/tests/fixtures/site-fixtures";
+import { clearResolverOptions } from "discourse-common/resolver";
 
 const LEGACY_ENV = !setupApplicationTest;
 
@@ -109,9 +110,9 @@ export function discourseModule(name, options) {
       hooks.beforeEach(function () {
         this.container = getOwner(this);
         this.registry = this.container.registry;
-
         this.owner = this.container;
         this.siteSettings = currentSettings();
+        clearResolverOptions();
       });
 
       this.getController = function (controllerName, properties) {

app/assets/javascripts/discourse/tests/integration/components/topic-list-test.js

@@ -40,6 +40,7 @@ discourseModule("Integration | Component | topic-list", function (hooks) {
     },
 
     async test(assert) {
+      assert.equal(this.selected.length, 0, "defaults to 0");
       await click("button.bulk-select");
       assert.ok(this.bulkSelectEnabled, "bulk select is enabled");