DEV: Replace deprecated Ember's array uniq and uniqBy (#35227)

This commit replaces several instances of `.uniq`, `.uniqBy`, and related
array deduplication methods with a new utility function
`uniqueItemsFromArray`. This change ensures proper deduplication logic
across the codebase while addressing the deprecation issues.

**Main Changes:**

* Created new utility function `uniqueItemsFromArray`: Located in a new
file, `array-tools.js`, this function provides a reusable and
configurable alternative for deduplication.
* Replaced old methods: Updated multiple files to use the new utility
function instead of deprecated or custom implementations for
deduplication.
* Replaced manual deduplication: Replace uses of `[...new Set(array)]`
to standardize the deduplication logic across the codebase.
* Added unit tests: Introduced thorough test coverage
(`array-tools-test.js`) to validate functionality and edge cases for the
utility function.
* Updated deprecation workflow: Added logging for deprecated uniq and
uniqBy methods to the `deprecation-workflow.js`.

This change is primarily focused on code quality improvements, ensuring
future-proof deduplication, and maintaining alignment with deprecation
guidelines.

app/assets/javascripts/admin/addon/components/admin-report.gjs

@@ -15,6 +15,7 @@ import concatClass from "discourse/helpers/concat-class";
 import icon from "discourse/helpers/d-icon";
 import number from "discourse/helpers/number";
 import { reportModeComponent } from "discourse/lib/admin-report-additional-modes";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { bind } from "discourse/lib/decorators";
 import { isTesting } from "discourse/lib/environment";
 import { exportEntity } from "discourse/lib/export-csv";
@@ -381,7 +382,7 @@ export default class AdminReport extends Component {
     // T and T+x, and all the ajax responses would occur after T+(x+y)
     // to avoid any inconsistencies we filter by period and make sure
     // the array contains only unique values
-    let filteredReports = this._reports.uniqBy("report_key");
+    let filteredReports = uniqueItemsFromArray(this._reports, "report_key");
     let foundReport;
 
     const sort = (report) => {

app/assets/javascripts/admin/addon/components/emoji-uploader.gjs

@@ -9,6 +9,7 @@ import didInsert from "@ember/render-modifiers/modifiers/did-insert";
 import { isEmpty } from "@ember/utils";
 import DButton from "discourse/components/d-button";
 import withEventValue from "discourse/helpers/with-event-value";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import discourseComputed from "discourse/lib/decorators";
 import UppyUpload from "discourse/lib/uppy/uppy-upload";
 import { i18n } from "discourse-i18n";
@@ -66,7 +67,7 @@ export default class EmojiUploader extends Component {
   createEmojiGroup(group) {
     let newEmojiGroups = this.newEmojiGroups;
     if (group !== DEFAULT_GROUP) {
-      newEmojiGroups = this.emojiGroups.concat([group]).uniq();
+      newEmojiGroups = uniqueItemsFromArray(this.emojiGroups.concat([group]));
     }
     this.setProperties({
       newEmojiGroups,

app/assets/javascripts/admin/addon/components/site-setting.gjs

@@ -14,6 +14,7 @@ import DButton from "discourse/components/d-button";
 import JsonSchemaEditorModal from "discourse/components/modal/json-schema-editor";
 import basePath from "discourse/helpers/base-path";
 import icon from "discourse/helpers/d-icon";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { bind } from "discourse/lib/decorators";
 import { deepEqual } from "discourse/lib/object";
 import { sanitize } from "discourse/lib/text";
@@ -383,7 +384,9 @@ export default class SiteSettingComponent extends Component {
   setDefaultValues() {
     this.buffered.set(
       "value",
-      this.bufferedValues.concat(this.defaultValues).uniq().join("|")
+      uniqueItemsFromArray(this.bufferedValues.concat(this.defaultValues)).join(
+        "|"
+      )
     );
     this.setting.validationMessage = null;
   }

app/assets/javascripts/admin/addon/components/site-settings/compact-list.gjs

@@ -2,6 +2,7 @@ import Component from "@glimmer/component";
 import { tracked } from "@glimmer/tracking";
 import { hash } from "@ember/helper";
 import { action } from "@ember/object";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { makeArray } from "discourse/lib/helpers";
 import ListSetting from "select-kit/components/list-setting";
 
@@ -17,13 +18,11 @@ export default class CompactList extends Component {
   }
 
   get settingChoices() {
-    return [
-      ...new Set([
-        ...makeArray(this.settingValue),
-        ...makeArray(this.args.setting.choices),
-        ...makeArray(this.createdChoices),
-      ]),
-    ];
+    return uniqueItemsFromArray([
+      ...makeArray(this.settingValue),
+      ...makeArray(this.args.setting.choices),
+      ...makeArray(this.createdChoices),
+    ]);
   }
 
   @action
@@ -33,9 +32,10 @@ export default class CompactList extends Component {
 
   @action
   onChangeChoices(choices) {
-    this.createdChoices = [
-      ...new Set([...makeArray(this.createdChoices), ...makeArray(choices)]),
-    ];
+    this.createdChoices = uniqueItemsFromArray([
+      ...makeArray(this.createdChoices),
+      ...makeArray(choices),
+    ]);
   }
 
   <template>

app/assets/javascripts/admin/addon/components/site-settings/file-types-list.gjs

@@ -5,6 +5,7 @@ import { action } from "@ember/object";
 import { service } from "@ember/service";
 import { isEmpty } from "@ember/utils";
 import DButton from "discourse/components/d-button";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { makeArray } from "discourse/lib/helpers";
 import { i18n } from "discourse-i18n";
 import ListSetting from "select-kit/components/list-setting";
@@ -39,13 +40,11 @@ export default class FileTypesList extends Component {
   }
 
   get settingChoices() {
-    return [
-      ...new Set([
-        ...makeArray(this.settingValue),
-        ...makeArray(this.args.setting.choices),
-        ...makeArray(this.createdChoices),
-      ]),
-    ];
+    return uniqueItemsFromArray([
+      ...makeArray(this.settingValue),
+      ...makeArray(this.args.setting.choices),
+      ...makeArray(this.createdChoices),
+    ]);
   }
 
   @action
@@ -55,9 +54,10 @@ export default class FileTypesList extends Component {
 
   @action
   onChangeChoices(choices) {
-    this.createdChoices = [
-      ...new Set([...makeArray(this.createdChoices), ...makeArray(choices)]),
-    ];
+    this.createdChoices = uniqueItemsFromArray([
+      ...makeArray(this.createdChoices),
+      ...makeArray(choices),
+    ]);
   }
 
   @action
@@ -79,7 +79,7 @@ export default class FileTypesList extends Component {
     }
 
     const oldTypes = this.args.value.split(TOKEN_SEPARATOR);
-    const newTypes = [...new Set([...oldTypes, ...types])];
+    const newTypes = uniqueItemsFromArray([...oldTypes, ...types]);
     const diffTypes = newTypes.filter((type) => !oldTypes.includes(type));
 
     if (isEmpty(diffTypes)) {

app/assets/javascripts/admin/addon/components/value-list.gjs

@@ -7,6 +7,7 @@ import { empty, reads } from "@ember/object/computed";
 import { TrackedArray } from "@ember-compat/tracked-built-ins";
 import { classNames } from "@ember-decorators/component";
 import DButton from "discourse/components/d-button";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import discourseComputed from "discourse/lib/decorators";
 import { makeArray } from "discourse/lib/helpers";
 import ComboBox from "select-kit/components/combo-box";
@@ -113,7 +114,7 @@ export default class ValueList extends Component {
     this.collection.removeObject(value);
 
     if (this.choices) {
-      this.set("choices", this.choices.concat([value]).uniq());
+      this.set("choices", uniqueItemsFromArray(this.choices.concat([value])));
     } else {
       this.set("choices", makeArray(value));
     }

app/assets/javascripts/admin/addon/models/web-hook.js

@@ -2,6 +2,7 @@ import { tracked } from "@glimmer/tracking";
 import { computed } from "@ember/object";
 import { isEmpty } from "@ember/utils";
 import { observes } from "@ember-decorators/object";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import discourseComputed from "discourse/lib/decorators";
 import Group from "discourse/models/group";
 import RestModel from "discourse/models/rest";
@@ -19,7 +20,10 @@ class WebHookExtras {
   }
 
   addCategories(categories) {
-    this.categories = this.categories.concat(categories).uniqBy((c) => c.id);
+    this.categories = uniqueItemsFromArray(
+      this.categories.concat(categories),
+      "id"
+    );
   }
 
   get categoriesById() {

app/assets/javascripts/admin/addon/services/admin-emojis.js

@@ -3,6 +3,7 @@ import EmberObject, { action } from "@ember/object";
 import Service, { service } from "@ember/service";
 import { ajax } from "discourse/lib/ajax";
 import { popupAjaxError } from "discourse/lib/ajax-error";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { i18n } from "discourse-i18n";
 
 const ALL_FILTER = "all";
@@ -35,7 +36,9 @@ export default class AdminEmojis extends Service {
   }
 
   get emojiGroups() {
-    return [DEFAULT_GROUP].concat(this.emojis.map((e) => e.group)).uniq();
+    return uniqueItemsFromArray(
+      [DEFAULT_GROUP].concat(this.emojis.map((e) => e.group))
+    );
   }
 
   get filteringGroups() {

app/assets/javascripts/admin/addon/services/admin-sidebar-state-manager.js

@@ -1,4 +1,5 @@
 import Service, { service } from "@ember/service";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import scrollLock from "discourse/lib/scroll-lock";
 import { ADMIN_PANEL, MAIN_PANEL } from "discourse/lib/sidebar/panels";
 import AdminSearchModal from "admin/components/modal/admin-search";
@@ -17,13 +18,11 @@ export default class AdminSidebarStateManager extends Service {
       return;
     }
 
-    this.keywords[link_name].navigation = [
-      ...new Set(
-        this.keywords[link_name].navigation.concat(
-          keywords.map((keyword) => keyword.toLowerCase())
-        )
-      ),
-    ];
+    this.keywords[link_name].navigation = uniqueItemsFromArray(
+      this.keywords[link_name].navigation.concat(
+        keywords.map((keyword) => keyword.toLowerCase())
+      )
+    );
   }
 
   maybeForceAdminSidebar(opts = {}) {

app/assets/javascripts/discourse/app/components/edit-category-general.gjs

@@ -9,6 +9,7 @@ import PluginOutlet from "discourse/components/plugin-outlet";
 import categoryBadge from "discourse/helpers/category-badge";
 import { categoryBadgeHTML } from "discourse/helpers/category-link";
 import lazyHash from "discourse/helpers/lazy-hash";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import {
   CATEGORY_STYLE_TYPES,
   CATEGORY_TEXT_COLORS,
@@ -47,12 +48,13 @@ export default class EditCategoryGeneral extends Component {
   @cached
   get backgroundColors() {
     const categories = this.site.get("categoriesList");
-    return this.siteSettings.category_colors
-      .split("|")
-      .filter(Boolean)
-      .map((i) => i.toUpperCase())
-      .concat(categories.map((c) => c.color.toUpperCase()))
-      .uniq();
+    return uniqueItemsFromArray(
+      this.siteSettings.category_colors
+        .split("|")
+        .filter(Boolean)
+        .map((i) => i.toUpperCase())
+        .concat(categories.map((c) => c.color.toUpperCase()))
+    );
   }
 
   @cached

app/assets/javascripts/discourse/app/components/edit-category-localizations.gjs

@@ -2,6 +2,7 @@ import { fn, hash } from "@ember/helper";
 import { service } from "@ember/service";
 import { eq } from "truth-helpers";
 import { buildCategoryPanel } from "discourse/components/edit-category-panel";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { i18n } from "discourse-i18n";
 
 export default class EditCategoryLocalizations extends buildCategoryPanel(
@@ -16,7 +17,7 @@ export default class EditCategoryLocalizations extends buildCategoryPanel(
         (obj) => obj.value
       );
     const committed = this.transientData.localizations.map((obj) => obj.locale);
-    const allLocales = [...supported, ...committed].uniq();
+    const allLocales = uniqueItemsFromArray([...supported, ...committed]);
 
     return allLocales.map((value) => ({
       name: this.languageNameLookup.getLanguageName(value),

app/assets/javascripts/discourse/app/components/emoji-picker/content.gjs

@@ -19,6 +19,7 @@ import replaceEmoji from "discourse/helpers/replace-emoji";
 import withEventValue from "discourse/helpers/with-event-value";
 import { ajax } from "discourse/lib/ajax";
 import { popupAjaxError } from "discourse/lib/ajax-error";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import {
   disableBodyScroll,
   enableBodyScroll,
@@ -90,9 +91,9 @@ export default class EmojiPicker extends Component {
   });
 
   addVisibleSections(sections) {
-    this.visibleSections = makeArray(this.visibleSections)
-      .concat(makeArray(sections))
-      .uniq();
+    this.visibleSections = uniqueItemsFromArray(
+      makeArray(this.visibleSections).concat(makeArray(sections))
+    );
   }
 
   get sections() {

app/assets/javascripts/discourse/app/components/form-template-field/tag-chooser.gjs

@@ -8,6 +8,7 @@ import { service } from "@ember/service";
 import { htmlSafe } from "@ember/template";
 import { not } from "truth-helpers";
 import icon from "discourse/helpers/d-icon";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { i18n } from "discourse-i18n";
 
 export default class TagChooserField extends Component {
@@ -111,10 +112,10 @@ export default class TagChooserField extends Component {
     set(
       this.composer.model,
       "tags",
-      [
+      uniqueItemsFromArray([
         ...this.tags.filter((tag) => !this.selectedTags.includes(tag)),
         ...selectedTags,
-      ].uniq()
+      ])
     );
   }
 

app/assets/javascripts/discourse/app/components/group-info.gjs

@@ -1,6 +1,7 @@
 import Component from "@glimmer/component";
 import PluginOutlet from "discourse/components/plugin-outlet";
 import lazyHash from "discourse/helpers/lazy-hash";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 
 export default class GroupInfo extends Component {
   <template>
@@ -24,7 +25,9 @@ export default class GroupInfo extends Component {
 
   get names() {
     const { full_name, display_name, name } = this.args.group;
-    return [...new Set([full_name, display_name, name].filter(Boolean))];
+    return uniqueItemsFromArray(
+      [full_name, display_name, name].filter(Boolean)
+    );
   }
 
   get name() {

app/assets/javascripts/discourse/app/controllers/badges/show.js

@@ -1,5 +1,6 @@
 import Controller, { inject as controller } from "@ember/controller";
 import EmberObject, { action } from "@ember/object";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import discourseComputed from "discourse/lib/decorators";
 import Badge from "discourse/models/badge";
 import UserBadge from "discourse/models/user-badge";
@@ -25,7 +26,7 @@ export default class ShowController extends Controller {
         id: 0,
         badge: Badge.create({ name: i18n("badges.none") }),
       }),
-      ...filteredList.uniqBy("badge.name"),
+      ...uniqueItemsFromArray(filteredList, "badge.name"),
     ];
   }
 

app/assets/javascripts/discourse/app/controllers/preferences/users.js

@@ -2,6 +2,7 @@ import Controller from "@ember/controller";
 import { action, computed } from "@ember/object";
 import { and } from "@ember/object/computed";
 import { popupAjaxError } from "discourse/lib/ajax-error";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import discourseComputed from "discourse/lib/decorators";
 import { makeArray } from "discourse/lib/helpers";
 import { i18n } from "discourse-i18n";
@@ -34,7 +35,7 @@ export default class UsersController extends Controller {
       usernames = usernames.split(",").filter(Boolean);
     }
 
-    return makeArray(usernames).uniq();
+    return uniqueItemsFromArray(makeArray(usernames));
   }
 
   @computed("model.allowed_pm_usernames")
@@ -45,17 +46,23 @@ export default class UsersController extends Controller {
       usernames = usernames.split(",").filter(Boolean);
     }
 
-    return makeArray(usernames).uniq();
+    return uniqueItemsFromArray(makeArray(usernames));
   }
 
   @action
   onChangeMutedUsernames(usernames) {
-    this.model.set("muted_usernames", usernames.uniq().join(","));
+    this.model.set(
+      "muted_usernames",
+      uniqueItemsFromArray(usernames).join(",")
+    );
   }
 
   @action
   onChangeAllowedPmUsernames(usernames) {
-    this.model.set("allowed_pm_usernames", usernames.uniq().join(","));
+    this.model.set(
+      "allowed_pm_usernames",
+      uniqueItemsFromArray(usernames).join(",")
+    );
   }
 
   @discourseComputed("model.user_option.allow_private_messages")

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

@@ -23,6 +23,7 @@ import { MIN_POSTS_COUNT } from "discourse/components/topic-map/topic-map-summar
 import { spinnerHTML } from "discourse/helpers/loading-spinner";
 import { ajax } from "discourse/lib/ajax";
 import { popupAjaxError } from "discourse/lib/ajax-error";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { BookmarkFormData } from "discourse/lib/bookmark-form-data";
 import { resetCachedTopicList } from "discourse/lib/cached-topic-list";
 import discourseComputed, { bind } from "discourse/lib/decorators";
@@ -1071,9 +1072,11 @@ export default class TopicController extends Controller {
   selectReplies(post) {
     ajax(`/posts/${post.id}/reply-ids.json`).then((replies) => {
       const replyIds = replies.map((r) => r.id);
-      this.selectedPostIds = [
-        ...new Set([...this.selectedPostIds, post.id, ...replyIds]),
-      ];
+      this.selectedPostIds = uniqueItemsFromArray([
+        ...this.selectedPostIds,
+        post.id,
+        ...replyIds,
+      ]);
       this._forceRefreshPostStream();
     });
   }

app/assets/javascripts/discourse/app/deprecation-workflow.js

@@ -313,6 +313,14 @@ const DeprecationWorkflow = new DiscourseDeprecationWorkflow([
     handler: "log",
     matchId: "discourse.native-array-extensions.toArray",
   },
+  {
+    handler: "log",
+    matchId: "discourse.native-array-extensions.uniq",
+  },
+  {
+    handler: "log",
+    matchId: "discourse.native-array-extensions.uniqBy",
+  },
   {
     handler: "log",
     matchId: "discourse.native-array-extensions.without",

app/assets/javascripts/discourse/app/lib/array-tools.js

@@ -1,3 +1,6 @@
+import { get } from "@ember/object";
+import { TrackedArray } from "@ember-compat/tracked-built-ins";
+
 /**
  * Removes all occurrences of a specified value from an array.
  *
@@ -30,3 +33,74 @@ export function removeValuesFromArray(array, values) {
 
   return array;
 }
+
+/**
+ * Normalizes the selector argument into a callable function.
+ * @param {(string|number|Function)} selector
+ * @returns {Function}
+ * @throws {Error} when selector type is invalid
+ */
+function buildSelector(selector) {
+  switch (typeof selector) {
+    case "number":
+      return (item) => item[selector];
+    case "string":
+      return selector.includes(".")
+        ? (item) => get(item, selector)
+        : (item) => item[selector];
+    case "function":
+      return selector;
+    default:
+      throw new Error(
+        "uniqueItemsFromArray: the `selector` argument must be a string/number key " +
+          `or a function, got ${typeof selector} instead`
+      );
+  }
+}
+
+/**
+ * Returns a new array with unique items based on the provided selector function.
+ * @param {Array} array
+ * @param {Function} selectorFn
+ * @returns {Array}
+ */
+function dedupeBy(array, selectorFn) {
+  const uniqueKeys = new Set();
+  const result = [];
+  for (const item of array) {
+    const key = selectorFn(item);
+    if (!uniqueKeys.has(key)) {
+      uniqueKeys.add(key);
+      result.push(item);
+    }
+  }
+  return result;
+}
+
+/**
+ * Returns a new array containing the unique elements from the input array.
+ * Elements are determined to be unique based on either strict equality or a specified condition.
+ *
+ * @param {Array} array - The input array from which unique elements are to be extracted.
+ * Must be a valid array. An error is thrown if the input is not an array.
+ * @param {(string|number|Function)} [selector] - Optional selector to determine uniqueness:
+ * - If undefined: uses strict equality comparison
+ * - If string/number: uses the value at the specified object property path
+ * - If function: uses the return value of the function called with each item
+ * @throws {Error} If array is not an Array or if selector is an invalid type
+ * @return {Array|TrackedArray} A new array with only unique elements (TrackedArray if input was TrackedArray)
+ */
+export function uniqueItemsFromArray(array, selector) {
+  if (!Array.isArray(array)) {
+    throw new Error(
+      `uniqueItemsFromArray expects an array as first argument, got ${typeof array} instead`
+    );
+  }
+
+  const items =
+    selector === undefined
+      ? [...new Set(array)]
+      : dedupeBy(array, buildSelector(selector));
+
+  return array instanceof TrackedArray ? new TrackedArray(items) : items;
+}

app/assets/javascripts/discourse/app/lib/bulk-select-helper.js

@@ -3,6 +3,7 @@ import { action } from "@ember/object";
 import { getOwner, setOwner } from "@ember/owner";
 import { service } from "@ember/service";
 import { TrackedArray } from "@ember-compat/tracked-built-ins";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { NotificationLevels } from "discourse/lib/notification-levels";
 import Topic from "discourse/models/topic";
 
@@ -33,7 +34,7 @@ export default class BulkSelectHelper {
   }
 
   get selectedCategoryIds() {
-    return this.selected.map((item) => item.category_id).uniq();
+    return uniqueItemsFromArray(this.selected.map((item) => item.category_id));
   }
 
   @action

app/assets/javascripts/discourse/app/lib/hashtag-decorator.js

@@ -1,4 +1,5 @@
 import { ajax } from "discourse/lib/ajax";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import domFromString from "discourse/lib/dom-from-string";
 import { getHashtagTypeClasses } from "discourse/lib/hashtag-type-registry";
 import { emojiUnescape } from "discourse/lib/text";
@@ -48,10 +49,9 @@ export function linkSeenHashtagsInContext(
     );
   });
 
-  return slugs
-    .map((slug) => slug.toLowerCase())
-    .uniq()
-    .filter((slug) => !checkedHashtags.has(slug));
+  return uniqueItemsFromArray(slugs.map((slug) => slug.toLowerCase())).filter(
+    (slug) => !checkedHashtags.has(slug)
+  );
 }
 
 function _findAndReplaceSeenHashtagPlaceholder(

app/assets/javascripts/discourse/app/lib/link-mentions.js

@@ -1,4 +1,5 @@
 import { ajax } from "discourse/lib/ajax";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import getURL from "discourse/lib/get-url";
 import { userPath } from "discourse/lib/url";
 import { formatUsername } from "discourse/lib/utilities";
@@ -80,12 +81,9 @@ export function linkSeenMentions(element, siteSettings) {
   const names = mentions.map((mention) => mention.innerText.slice(1));
   updateFound(mentions, names);
 
-  return names
-    .uniq()
-    .filter(
-      (name) =>
-        !checked[name] && name.length >= siteSettings.min_username_length
-    );
+  return uniqueItemsFromArray(names).filter(
+    (name) => !checked[name] && name.length >= siteSettings.min_username_length
+  );
 }
 
 export async function fetchUnseenMentions({ names, topicId, allowedNames }) {

app/assets/javascripts/discourse/app/lib/multi-cache.js

@@ -1,6 +1,8 @@
 // Used for Category.asyncFindByIds
 //
 // It's a cache that handles multiple lookups at a time.
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
+
 export class MultiCache {
   constructor(cb) {
     this.cb = cb;
@@ -22,7 +24,7 @@ export class MultiCache {
     this.fetchTimes = [this.fetchTimes[this.fetchTimes.length - 1], new Date()];
 
     const notFound = [];
-    ids = ids.uniq();
+    ids = uniqueItemsFromArray(ids);
 
     for (const id of ids) {
       if (!this.values.has(id)) {

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

@@ -1,6 +1,7 @@
 import { dasherize, underscore } from "@ember/string";
 import { Promise } from "rsvp";
 import { ajax } from "discourse/lib/ajax";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import discourseComputed from "discourse/lib/decorators";
 import RestModel from "discourse/models/rest";
 import I18n, { i18n } from "discourse-i18n";
@@ -50,8 +51,10 @@ export default class Reviewable extends RestModel {
 
   @discourseComputed("humanNoun")
   flaggedReviewableContextQuestion(humanNoun) {
-    const uniqueReviewableScores =
-      this.reviewable_scores.uniqBy("score_type.type");
+    const uniqueReviewableScores = uniqueItemsFromArray(
+      this.reviewable_scores,
+      "score_type.type"
+    );
 
     if (uniqueReviewableScores.length === 1) {
       if (uniqueReviewableScores[0].score_type.type === "notify_moderators") {
@@ -62,9 +65,11 @@ export default class Reviewable extends RestModel {
     }
 
     const listOfQuestions = I18n.listJoiner(
-      uniqueReviewableScores
-        .map((score) => score.score_type.title.toLowerCase())
-        .uniq(),
+      uniqueItemsFromArray(
+        uniqueReviewableScores.map((score) =>
+          score.score_type.title.toLowerCase()
+        )
+      ),
       i18n("review.context_question.delimiter")
     );
 

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

@@ -12,6 +12,7 @@ import { htmlSafe } from "@ember/template";
 import { isEmpty } from "@ember/utils";
 import { Promise } from "rsvp";
 import { ajax } from "discourse/lib/ajax";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { url } from "discourse/lib/computed";
 import {
   INTERFACE_COLOR_MODES,
@@ -1160,8 +1161,7 @@ export default class User extends RestModel.extend(Evented) {
       }
     });
 
-    return titles
-      .uniq()
+    return uniqueItemsFromArray(titles)
       .sort()
       .map((title) => {
         return {
@@ -1240,7 +1240,7 @@ export default class User extends RestModel.extend(Evented) {
   calculateMutedIds(notificationLevel, id, type) {
     const muted_ids = this.get(type);
     if (notificationLevel === NotificationLevels.MUTED) {
-      return muted_ids.concat(id).uniq();
+      return uniqueItemsFromArray(muted_ids.concat(id));
     } else {
       return muted_ids.filter((existing_id) => existing_id !== id);
     }

app/assets/javascripts/discourse/app/static/markdown-it/mentions-parser.js

@@ -1,3 +1,5 @@
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
+
 export default class MentionsParser {
   constructor(engine) {
     this.engine = engine;
@@ -6,7 +8,7 @@ export default class MentionsParser {
   parse(markdown) {
     const tokens = this.engine.parse(markdown);
     const mentions = this.#parse(tokens);
-    return [...new Set(mentions)];
+    return uniqueItemsFromArray(mentions);
   }
 
   #parse(tokens) {

app/assets/javascripts/discourse/app/static/prosemirror/extensions/mention.js

@@ -1,5 +1,6 @@
 import { mentionRegex } from "pretty-text/mentions";
 import { ajax } from "discourse/lib/ajax";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import getURL from "discourse/lib/get-url";
 import { isBoundary } from "discourse/static/prosemirror/lib/markdown-it";
 import { i18n } from "discourse-i18n";
@@ -159,7 +160,7 @@ const extension = {
 
 async function fetchMentions(names, context) {
   // only fetch new mentions that are not already validated
-  names = names.uniq().filter((name) => {
+  names = uniqueItemsFromArray(names).filter((name) => {
     return !VALID_MENTIONS.has(name) && !INVALID_MENTIONS.has(name);
   });
 

app/assets/javascripts/discourse/app/widgets/post-links.js

@@ -1,4 +1,5 @@
 import { h } from "virtual-dom";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { iconNode } from "discourse/lib/icon-library";
 import { replaceEmoji } from "discourse/widgets/emoji";
 import { createWidget } from "discourse/widgets/widget";
@@ -41,7 +42,10 @@ export default createWidget("post-links", {
     }
 
     // only show incoming
-    const links = this.attrs.links.filter((l) => l.reflection).uniqBy("title");
+    const links = uniqueItemsFromArray(
+      this.attrs.links.filter((l) => l.reflection),
+      "title"
+    );
 
     if (links.length === 0) {
       return;

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

@@ -3,6 +3,7 @@ import { module, test } from "qunit";
 import {
   removeValueFromArray,
   removeValuesFromArray,
+  uniqueItemsFromArray,
 } from "discourse/lib/array-tools";
 
 module("Unit | Lib | array-tools", function () {
@@ -176,4 +177,206 @@ module("Unit | Lib | array-tools", function () {
       assert.deepEqual(twice, [3], "second call is a no-op");
     });
   });
+
+  module("uniqueItemsFromArray()", function () {
+    test("throws when input is not an array", function (assert) {
+      assert.throws(
+        () => uniqueItemsFromArray(null),
+        /expects an array/,
+        "null is rejected"
+      );
+      assert.throws(
+        () => uniqueItemsFromArray(undefined),
+        /expects an array/,
+        "undefined is rejected"
+      );
+      assert.throws(
+        () => uniqueItemsFromArray("not array"),
+        /expects an array/,
+        "string is rejected"
+      );
+      assert.throws(
+        () => uniqueItemsFromArray({}),
+        /expects an array/,
+        "object is rejected"
+      );
+      assert.throws(
+        () => uniqueItemsFromArray(123),
+        /expects an array/,
+        "number is rejected"
+      );
+    });
+
+    test("returns a new empty array for empty input", function (assert) {
+      const input = [];
+      const result = uniqueItemsFromArray(input);
+
+      assert.notStrictEqual(
+        result,
+        input,
+        "returns a new array instance even for empty input"
+      );
+      assert.deepEqual(result, [], "result is empty");
+    });
+
+    test("deduplicates primitives by strict equality", function (assert) {
+      const input = [1, 1, 2, 3, 2, 3, 4, 4, 4];
+      const result = uniqueItemsFromArray(input);
+
+      assert.deepEqual(result, [1, 2, 3, 4], "unique primitives retained");
+      assert.notStrictEqual(
+        result,
+        input,
+        "does not return original array reference"
+      );
+    });
+
+    test("retains first occurrence order", function (assert) {
+      const input = ["b", "a", "b", "c", "a", "d"];
+      const result = uniqueItemsFromArray(input);
+
+      assert.deepEqual(
+        result,
+        ["b", "a", "c", "d"],
+        "order corresponds to first occurrences"
+      );
+    });
+
+    test("uses identity for objects and symbols", function (assert) {
+      const a1 = { id: 1 };
+      const a2 = { id: 1 }; // different reference
+      const b = { id: 2 };
+      const s1 = Symbol("x");
+      const s2 = Symbol("x");
+
+      const input = [a1, a1, a2, b, s1, s1, s2];
+      const result = uniqueItemsFromArray(input);
+
+      assert.strictEqual(result[0], a1, "first a1 kept");
+      assert.strictEqual(result[1], a2, "distinct object with same shape kept");
+      assert.strictEqual(result[2], b, "b kept");
+      assert.strictEqual(result[3], s1, "first symbol for x is kept");
+      assert.strictEqual(result[4], s2, "second symbol for x is kept");
+
+      assert.strictEqual(
+        result.length,
+        5,
+        "duplicates by reference removed only"
+      );
+    });
+
+    test("returns TrackedArray when input is TrackedArray", function (assert) {
+      const tracked = new TrackedArray([1, 2, 2, 3, 3, 3]);
+      const result = uniqueItemsFromArray(tracked);
+
+      assert.true(result instanceof TrackedArray, "result is a TrackedArray");
+      assert.deepEqual(Array.from(result), [1, 2, 3], "deduplicated correctly");
+      assert.notStrictEqual(
+        result,
+        tracked,
+        "returns a new TrackedArray instance"
+      );
+    });
+
+    test("does not mutate the input array", function (assert) {
+      const input = [1, 1, 2];
+      const snapshot = input.slice();
+
+      const result = uniqueItemsFromArray(input);
+
+      assert.deepEqual(input, snapshot, "input remains unchanged");
+      assert.deepEqual(result, [1, 2], "result is deduplicated");
+    });
+
+    test("handles heterogeneous arrays", function (assert) {
+      const sym = Symbol("s");
+      const input = [0, false, null, undefined, "", sym, 0, false, NaN, NaN];
+
+      const result = uniqueItemsFromArray(input);
+
+      // Set treats NaN as the same value, which is desired here
+      assert.strictEqual(
+        result.length,
+        7,
+        "expected number of unique elements"
+      );
+      assert.deepEqual(
+        result.slice(0, 6),
+        [0, false, null, undefined, "", sym],
+        "first occurrences retained"
+      );
+      assert.true(Number.isNaN(result[6]), "NaN retained once");
+    });
+
+    test("treats NaN as a single unique value", function (assert) {
+      const result = uniqueItemsFromArray([NaN, NaN, 1, NaN]);
+      assert.strictEqual(result.length, 2, "NaN appears once among uniques");
+      assert.true(Number.isNaN(result[0]), "NaN present");
+    });
+
+    // selector-based behavior
+
+    test("selector: number index picks property by numeric key", function (assert) {
+      const input = [
+        ["a", 1],
+        ["a", 2],
+        ["b", 3],
+        ["b", 4],
+      ];
+      const result = uniqueItemsFromArray(input, 0);
+      assert.deepEqual(
+        result,
+        [
+          ["a", 1],
+          ["b", 3],
+        ],
+        "unique by index 0"
+      );
+    });
+
+    test("selector: string key picks shallow property", function (assert) {
+      const input = [
+        { id: 1, name: "x" },
+        { id: 1, name: "x2" },
+        { id: 2, name: "y" },
+      ];
+      const result = uniqueItemsFromArray(input, "id");
+      assert.strictEqual(result.length, 2, "two unique ids");
+      assert.deepEqual(
+        result.map((o) => o.name),
+        ["x", "y"],
+        "keeps first by id"
+      );
+    });
+
+    test("selector: dotted path uses Ember get for nested property access", function (assert) {
+      const input = [
+        { user: { id: 10 } },
+        { user: { id: 10 } },
+        { user: { id: 11 } },
+      ];
+      const result = uniqueItemsFromArray(input, "user.id");
+      assert.strictEqual(result.length, 2, "two unique nested ids");
+      assert.deepEqual(
+        result.map((o) => o.user.id),
+        [10, 11],
+        "keeps first by nested id"
+      );
+    });
+
+    test("selector: function selector determines uniqueness", function (assert) {
+      const input = [
+        { id: 1, name: "Alice" },
+        { id: 1, name: "Alice2" },
+        { id: 2, name: "Bob" },
+      ];
+      const result = uniqueItemsFromArray(input, (o) => o.id);
+      assert.strictEqual(result.length, 2, "two unique ids");
+      assert.deepEqual(
+        result.map((o) => o.name),
+        ["Alice", "Bob"],
+        "keeps first by function selector"
+      );
+    });
+  });
 });

app/assets/javascripts/select-kit/addon/components/list-setting.js

@@ -1,6 +1,7 @@
 import { computed } from "@ember/object";
 import { readOnly } from "@ember/object/computed";
 import { classNames } from "@ember-decorators/component";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { makeArray } from "discourse/lib/helpers";
 import MultiSelectComponent from "select-kit/components/multi-select";
 import {
@@ -41,7 +42,9 @@ export default class ListSetting extends MultiSelectComponent {
 
   deselect(value) {
     this.onChangeChoices &&
-      this.onChangeChoices([...new Set([value, ...makeArray(this.choices)])]);
+      this.onChangeChoices(
+        uniqueItemsFromArray([value, ...makeArray(this.choices)])
+      );
 
     super.deselect(...arguments);
   }

app/assets/javascripts/select-kit/addon/components/multi-select.gjs

@@ -5,6 +5,7 @@ import { isPresent } from "@ember/utils";
 import { classNames } from "@ember-decorators/component";
 import { and, not } from "truth-helpers";
 import componentForCollection from "discourse/helpers/component-for-collection";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { makeArray } from "discourse/lib/helpers";
 import { i18n } from "discourse-i18n";
 import SelectKitComponent, {
@@ -131,7 +132,7 @@ export default class MultiSelect extends SelectKitComponent {
       );
 
       this.selectKit.change(
-        [...new Set(newValues)],
+        uniqueItemsFromArray(newValues),
         newContent.length
           ? newContent
           : makeArray(this.defaultItem(value, value))

app/assets/javascripts/select-kit/addon/components/select-kit.js

@@ -13,6 +13,7 @@ import {
 } from "@ember-decorators/component";
 import { createPopper } from "@popperjs/core";
 import { Promise } from "rsvp";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import discourseDebounce from "discourse/lib/debounce";
 import { bind as bindDecorator } from "discourse/lib/decorators";
 import deprecated from "discourse/lib/deprecated";
@@ -729,9 +730,9 @@ export default class SelectKit extends Component {
         content = this.selectKit.modifyContent(content).filter(Boolean);
 
         if (this.selectKit.valueProperty) {
-          content = content.uniqBy(this.selectKit.valueProperty);
+          content = uniqueItemsFromArray(content, this.selectKit.valueProperty);
         } else {
-          content = content.uniq();
+          content = uniqueItemsFromArray(content);
         }
 
         if (this.selectKit.options.limitMatches) {

app/assets/javascripts/select-kit/addon/components/tag-chooser.js

@@ -1,6 +1,7 @@
 import { action, computed } from "@ember/object";
 import { service } from "@ember/service";
 import { attributeBindings, classNames } from "@ember-decorators/component";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { bind } from "discourse/lib/decorators";
 import { makeArray } from "discourse/lib/helpers";
 import MultiSelectComponent from "select-kit/components/multi-select";
@@ -67,14 +68,14 @@ export default class TagChooser extends MultiSelectComponent {
 
   @computed("tags.[]")
   get value() {
-    return makeArray(this.tags).uniq();
+    return uniqueItemsFromArray(makeArray(this.tags));
   }
 
   @computed("tags.[]")
   get content() {
-    return makeArray(this.tags)
-      .uniq()
-      .map((t) => this.defaultItem(t, t));
+    return uniqueItemsFromArray(makeArray(this.tags)).map((t) =>
+      this.defaultItem(t, t)
+    );
   }
 
   @action
@@ -112,10 +113,9 @@ export default class TagChooser extends MultiSelectComponent {
     };
 
     if (selectedTags.length || this.blockedTags.length) {
-      data.selected_tags = selectedTags
-        .concat(this.blockedTags)
-        .uniq()
-        .slice(0, 100);
+      data.selected_tags = uniqueItemsFromArray(
+        selectedTags.concat(this.blockedTags)
+      ).slice(0, 100);
     }
 
     if (!this.everyTag) {
@@ -158,6 +158,6 @@ export default class TagChooser extends MultiSelectComponent {
       results = results.sort((a, b) => a.id > b.id);
     }
 
-    return results.uniqBy("id");
+    return uniqueItemsFromArray(results, "id");
   }
 }

app/assets/javascripts/select-kit/addon/components/tag-group-chooser.js

@@ -1,6 +1,7 @@
 import { computed } from "@ember/object";
 import { service } from "@ember/service";
 import { classNames } from "@ember-decorators/component";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { bind } from "discourse/lib/decorators";
 import { makeArray } from "discourse/lib/helpers";
 import MultiSelectComponent from "select-kit/components/multi-select";
@@ -27,14 +28,14 @@ export default class TagGroupChooser extends MultiSelectComponent {
 
   @computed("tagGroups.[]")
   get value() {
-    return makeArray(this.tagGroups).uniq();
+    return uniqueItemsFromArray(makeArray(this.tagGroups));
   }
 
   @computed("tagGroups.[]")
   get content() {
-    return makeArray(this.tagGroups)
-      .uniq()
-      .map((t) => this.defaultItem(t, t));
+    return uniqueItemsFromArray(makeArray(this.tagGroups)).map((t) =>
+      this.defaultItem(t, t)
+    );
   }
 
   validateCreate(filter, content) {

plugins/chat/assets/javascripts/discourse/lib/chat-messages-manager.js

@@ -1,5 +1,6 @@
 import { cached, tracked } from "@glimmer/tracking";
 import { setOwner } from "@ember/owner";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 
 export default class ChatMessagesManager {
   @tracked messages = [];
@@ -27,10 +28,10 @@ export default class ChatMessagesManager {
   }
 
   addMessages(messages = []) {
-    this.messages = this.messages
-      .concat(messages)
-      .uniqBy("id")
-      .sort((a, b) => a.createdAt - b.createdAt);
+    this.messages = uniqueItemsFromArray(
+      this.messages.concat(messages),
+      "id"
+    ).sort((a, b) => a.createdAt - b.createdAt);
   }
 
   findMessage(messageId) {

plugins/chat/assets/javascripts/discourse/services/chat.js

@@ -5,6 +5,7 @@ import { cancel, next } from "@ember/runloop";
 import Service, { service } from "@ember/service";
 import { ajax } from "discourse/lib/ajax";
 import { popupAjaxError } from "discourse/lib/ajax-error";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { bind } from "discourse/lib/decorators";
 import deprecated from "discourse/lib/deprecated";
 import discourseLater from "discourse/lib/later";
@@ -392,10 +393,11 @@ export default class Chat extends Service {
   }
 
   upsertDmChannelForUser(channel, user) {
-    const usernames = (channel.chatable.users || [])
-      .map((item) => item.username)
-      .concat(user.username)
-      .uniq();
+    const usernames = uniqueItemsFromArray(
+      (channel.chatable.users || [])
+        .map((item) => item.username)
+        .concat(user.username)
+    );
 
     return this.upsertDmChannel({ usernames });
   }
@@ -411,8 +413,12 @@ export default class Chat extends Service {
     return ajax("/chat/api/direct-message-channels.json", {
       method: "POST",
       data: {
-        target_usernames: targets.usernames?.uniq(),
-        target_groups: targets.groups?.uniq(),
+        target_usernames: targets.usernames
+          ? uniqueItemsFromArray(targets.usernames)
+          : null,
+        target_groups: targets.groups
+          ? uniqueItemsFromArray(targets.groups)
+          : null,
         upsert: opts.upsert,
         name: opts.name,
       },
@@ -434,7 +440,7 @@ export default class Chat extends Service {
   // participant to fetch the channel for.
   getDmChannelForUsernames(usernames) {
     return ajax("/chat/direct_messages.json", {
-      data: { usernames: usernames.uniq().join(",") },
+      data: { usernames: uniqueItemsFromArray(usernames).join(",") },
     });
   }
 

plugins/discourse-ai/assets/javascripts/discourse/components/ai-split-topic-suggester.gjs

@@ -9,6 +9,7 @@ import DButton from "discourse/components/d-button";
 import categoryBadge from "discourse/helpers/category-badge";
 import { ajax } from "discourse/lib/ajax";
 import { popupAjaxError } from "discourse/lib/ajax-error";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import DMenu from "float-kit/components/d-menu";
 
 export default class AiSplitTopicSuggester extends Component {
@@ -88,10 +89,10 @@ export default class AiSplitTopicSuggester extends Component {
       if (this.args.currentValue) {
         if (Array.isArray(this.args.currentValue)) {
           const updatedTags = [...this.args.currentValue, suggestion];
-          this.args.updateAction([...new Set(updatedTags)]);
+          this.args.updateAction(uniqueItemsFromArray(updatedTags));
         } else {
           const updatedTags = [this.args.currentValue, suggestion];
-          this.args.updateAction([...new Set(updatedTags)]);
+          this.args.updateAction(uniqueItemsFromArray(updatedTags));
         }
       } else {
         if (Array.isArray(suggestion)) {

plugins/discourse-local-dates/assets/javascripts/lib/local-date-builder.js

@@ -1,3 +1,4 @@
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { renderIcon } from "discourse/lib/icon-library";
 import { i18n } from "discourse-i18n";
 import DateWithZoneHelper from "./date-with-zone-helper";
@@ -141,7 +142,7 @@ export default class LocalDateBuilder {
       });
     });
 
-    return previewedTimezones.uniqBy("timezone");
+    return uniqueItemsFromArray(previewedTimezones, "timezone");
   }
 
   _isEqualZones(timezoneA, timezoneB) {

plugins/discourse-reactions/assets/javascripts/discourse/components/discourse-reactions-counter.gjs

@@ -6,6 +6,7 @@ import { service } from "@ember/service";
 import { TrackedObject } from "@ember-compat/tracked-built-ins";
 import { and } from "truth-helpers";
 import DButton from "discourse/components/d-button";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { bind } from "discourse/lib/decorators";
 import closeOnClickOutside from "discourse/modifiers/close-on-click-outside";
 import CustomReaction from "../models/discourse-reactions-custom-reaction";
@@ -26,7 +27,7 @@ export default class DiscourseReactionsCounter extends Component {
   }
 
   reactionsChanged(data) {
-    data.reactions.uniq().forEach((reaction) => {
+    uniqueItemsFromArray(data.reactions).forEach((reaction) => {
       this.getUsers(reaction);
     });
   }

plugins/styleguide/assets/javascripts/discourse/components/styleguide-icons.gjs

@@ -2,6 +2,7 @@
 import Component from "@ember/component";
 import { classNames, tagName } from "@ember-decorators/component";
 import icon from "discourse/helpers/d-icon";
+import { uniqueItemsFromArray } from "discourse/lib/array-tools";
 import { afterRender } from "discourse/lib/decorators";
 import { REPLACEMENTS } from "discourse/lib/icon-library";
 import discourseLater from "discourse/lib/later";
@@ -22,7 +23,7 @@ export default class StyleguideIcons extends Component {
     if (symbols.length > 0) {
       let ids = Array.from(symbols).map((item) => item.id);
       ids.push(...Object.keys(REPLACEMENTS));
-      this.set("iconIds", [...new Set(ids.sort())]);
+      this.set("iconIds", uniqueItemsFromArray(ids).sort());
     } else {
       // Let's try again a short time later if there are no svgs loaded yet
       discourseLater(this, this.setIconIds, 1500);