DEV: Fix failing share topic tests (#16309)

Since 3fd7b31a2aa79dabcc34625c10877fcf737d5855 some tests
were failing with this error:

> Error: Unhandled request in test environment: /c/feature/find_by_slug.json
> (GET) at http://localhost:7357/assets/test-helpers.js

This commit fixes the issue by adding the missing pretender. Also
noticed while fixing this that the parameter for the translation
was incorrect -- it was `group` instead of `groupNames`, so that
is fixed here too, along with moving the onShow functions into
@afterRender decorated private functions. There is no need for the
appevent listeners.

app/assets/javascripts/discourse/app/controllers/share-topic.js

@@ -1,7 +1,9 @@
 import Controller from "@ember/controller";
 import { action } from "@ember/object";
 import { getAbsoluteURL } from "discourse-common/lib/get-url";
-import discourseComputed from "discourse-common/utils/decorators";
+import discourseComputed, {
+  afterRender,
+} from "discourse-common/utils/decorators";
 import { ajax } from "discourse/lib/ajax";
 import { extractError } from "discourse/lib/ajax-error";
 import Sharing from "discourse/lib/sharing";
@@ -16,38 +18,26 @@ export default Controller.extend(
   bufferedProperty("invite"),
   {
     topic: null,
-    restrictedGroups: null,
 
     onShow() {
       this.set("showNotifyUsers", false);
 
-      this.appEvents.on(
-        "modal:body-shown",
-        this,
-        this.showRestrictedGroupWarning
-      );
+      this._showRestrictedGroupWarning();
     },
 
-    onClose() {
-      this.appEvents.off(
-        "modal:body-shown",
-        this,
-        this.showRestrictedGroupWarning
-      );
-    },
-
-    showRestrictedGroupWarning() {
+    @afterRender
+    _showRestrictedGroupWarning() {
       if (!this.model) {
         return;
       }
 
       Category.reloadBySlugPath(this.model.slug).then((result) => {
         const groups = result.category.group_permissions.mapBy("group_name");
-        if (groups && !groups.any((x) => x === "everyone")) {
+        if (groups && !groups.any((group) => group === "everyone")) {
           this.flash(
             I18n.t("topic.share.restricted_groups", {
               count: groups.length,
-              groups: groups.join(", "),
+              groupNames: groups.join(", "),
             }),
             "warning"
           );

app/assets/javascripts/discourse/tests/acceptance/share-topic-test.js

@@ -1,9 +1,11 @@
 import CategoryFixtures from "discourse/tests/fixtures/category-fixtures";
+import I18n from "I18n";
 import { click, visit } from "@ember/test-helpers";
 import {
   acceptance,
   count,
   exists,
+  query,
   queryAll,
 } from "discourse/tests/helpers/qunit-helpers";
 import selectKit from "discourse/tests/helpers/select-kit-helper";
@@ -29,6 +31,10 @@ acceptance("Share and Invite modal", function (needs) {
     await click("#topic-footer-button-share-and-invite");
 
     assert.ok(exists(".share-topic-modal"), "it shows the modal");
+    assert.notOk(
+      exists("#modal-alert.alert-warning"),
+      "it does not show the alert with restricted groups"
+    );
 
     assert.ok(
       queryAll("input.invite-link")
@@ -71,6 +77,14 @@ acceptance("Share and Invite modal", function (needs) {
       exists("#modal-alert.alert-warning"),
       "it shows restricted warning"
     );
+    assert.strictEqual(
+      query("#modal-alert.alert-warning").innerText,
+      I18n.t("topic.share.restricted_groups", {
+        count: 1,
+        groupNames: "moderators",
+      }),
+      "it shows correct restricted group name"
+    );
   });
 });
 
@@ -78,6 +92,12 @@ acceptance("Share and Invite modal - mobile", function (needs) {
   needs.user();
   needs.mobileView();
 
+  needs.pretender((server, helper) => {
+    server.get("/c/feature/find_by_slug.json", () =>
+      helper.response(200, CategoryFixtures["/c/1/show.json"])
+    );
+  });
+
   test("Topic footer mobile button", async function (assert) {
     await visit("/t/internationalization-localization/280");
 
@@ -97,6 +117,13 @@ acceptance("Share and Invite modal - mobile", function (needs) {
 acceptance("Share url with badges disabled - desktop", function (needs) {
   needs.user();
   needs.settings({ enable_badges: false });
+
+  needs.pretender((server, helper) => {
+    server.get("/c/feature/find_by_slug.json", () =>
+      helper.response(200, CategoryFixtures["/c/1/show.json"])
+    );
+  });
+
   test("topic footer button - badges disabled - desktop", async function (assert) {
     await visit("/t/internationalization-localization/280");
     await click("#topic-footer-button-share-and-invite");