DEV: Enable ember/no-classic-classes eslint rule (#28610)

.eslintrc.cjs

@@ -1 +1,5 @@
-module.exports = require("@discourse/lint-configs/eslint");
+const config = require("@discourse/lint-configs/eslint");
+
+config.rules["ember/no-classic-classes"] = "error";
+
+module.exports = config;

app/assets/javascripts/discourse/tests/unit/lib/computed-test.js

@@ -31,6 +31,7 @@ module("Unit | Utility | computed", function (hooks) {
   test("setting", function (assert) {
     const siteSettings = getOwner(this).lookup("service:site-settings");
 
+    // eslint-disable-next-line ember/no-classic-classes
     let t = EmberObject.extend({
       siteSettings,
       vehicle: setting("vehicle"),
@@ -50,6 +51,7 @@ module("Unit | Utility | computed", function (hooks) {
   });
 
   test("propertyEqual", function (assert) {
+    // eslint-disable-next-line ember/no-classic-classes
     let t = EmberObject.extend({
       same: propertyEqual("cookies", "biscuits"),
     }).create({
@@ -63,6 +65,7 @@ module("Unit | Utility | computed", function (hooks) {
   });
 
   test("propertyNotEqual", function (assert) {
+    // eslint-disable-next-line ember/no-classic-classes
     let t = EmberObject.extend({
       diff: propertyNotEqual("cookies", "biscuits"),
     }).create({
@@ -76,6 +79,7 @@ module("Unit | Utility | computed", function (hooks) {
   });
 
   test("fmt", function (assert) {
+    // eslint-disable-next-line ember/no-classic-classes
     let t = EmberObject.extend({
       exclaimyUsername: fmt("username", "!!! %@ !!!"),
       multiple: fmt("username", "mood", "%@ is %@"),
@@ -110,6 +114,7 @@ module("Unit | Utility | computed", function (hooks) {
   });
 
   test("i18n", function (assert) {
+    // eslint-disable-next-line ember/no-classic-classes
     let t = EmberObject.extend({
       exclaimyUsername: i18n("username", "!!! %@ !!!"),
       multiple: i18n("username", "mood", "%@ is %@"),
@@ -146,6 +151,7 @@ module("Unit | Utility | computed", function (hooks) {
   test("url", function (assert) {
     let t, testClass;
 
+    // eslint-disable-next-line ember/no-classic-classes
     testClass = EmberObject.extend({
       userUrl: url("username", "/u/%@"),
     });
@@ -168,6 +174,7 @@ module("Unit | Utility | computed", function (hooks) {
 
   test("htmlSafe", function (assert) {
     const cookies = "<p>cookies and <b>biscuits</b></p>";
+    // eslint-disable-next-line ember/no-classic-classes
     const t = EmberObject.extend({
       desc: htmlSafe("cookies"),
     }).create({ cookies });

app/assets/javascripts/discourse/tests/unit/utils/decorators-test.js

@@ -1,5 +1,3 @@
-// eslint-disable ember/no-classic-classes
-
 import Component from "@ember/component";
 import EmberObject from "@ember/object";
 import { clearRender, render, settled } from "@ember/test-helpers";
@@ -16,6 +14,7 @@ import discourseComputed, {
   on,
 } from "discourse-common/utils/decorators";
 
+// eslint-disable-next-line ember/no-classic-classes
 const fooComponent = Component.extend({
   classNames: ["foo-component"],
 
@@ -39,6 +38,7 @@ const fooComponent = Component.extend({
   },
 });
 
+// eslint-disable-next-line ember/no-classic-classes
 const EmberObjectComponent = Component.extend({
   name: "",
   layout: hbs`<span class="ember-object-component">{{this.text}}</span>`,
@@ -59,6 +59,7 @@ class NativeComponent extends Component {
   }
 }
 
+// eslint-disable-next-line ember/no-classic-classes
 const TestStub = EmberObject.extend({
   counter: 0,
   otherCounter: 0,
@@ -228,6 +229,7 @@ module("Unit | Utils | decorators", function (hooks) {
       };
     });
 
+    // eslint-disable-next-line ember/no-classic-classes
     const ExtendWithObserver = EmberObject.extend({
       counter: 0,
       @observes("value")
@@ -267,6 +269,7 @@ module("Unit | Utils | decorators", function (hooks) {
       };
     });
 
+    // eslint-disable-next-line ember/no-classic-classes
     const ExtendWithOn = EmberObject.extend({
       counter: 0,
       @on("init")