DEV: Make `screen-track` a regular service (#14983)

app/assets/javascripts/application.js

@@ -74,7 +74,6 @@
 //= require ./discourse/app/lib/link-mentions
 //= require ./discourse/app/components/site-header
 //= require ./discourse/app/components/d-editor
-//= require ./discourse/app/lib/screen-track
 //= require ./discourse/app/routes/discourse
 //= require ./discourse/app/routes/build-topic-route
 //= require ./discourse/app/routes/restricted-user

app/assets/javascripts/discourse/app/pre-initializers/inject-discourse-objects.js

@@ -5,7 +5,6 @@ import PrivateMessageTopicTrackingState from "discourse/models/private-message-t
 import DiscourseLocation from "discourse/lib/discourse-location";
 import KeyValueStore from "discourse/lib/key-value-store";
 import MessageBus from "message-bus-client";
-import ScreenTrack from "discourse/lib/screen-track";
 import SearchService from "discourse/services/search";
 import Session from "discourse/models/session";
 import Site from "discourse/models/site";
@@ -69,16 +68,6 @@ export default {
     const session = Session.current();
     app.register("session:main", session, { instantiate: false });
 
-    // TODO: Automatically register this service
-    const screenTrack = new ScreenTrack(
-      topicTrackingState,
-      siteSettings,
-      session,
-      currentUser,
-      container.lookup("service:app-events")
-    );
-    app.register("service:screen-track", screenTrack, { instantiate: false });
-
     app.register("location:discourse-location", DiscourseLocation);
 
     const keyValueStore = new KeyValueStore("discourse_");
@@ -87,7 +76,6 @@ export default {
 
     ALL_TARGETS.forEach((t) => {
       app.inject(t, "appEvents", "service:app-events");
-      app.inject(t, "topicTrackingState", "topic-tracking-state:main");
       app.inject(t, "pmTopicTrackingState", "pm-topic-tracking-state:main");
       app.inject(t, "store", "service:store");
       app.inject(t, "site", "site:main");
@@ -99,10 +87,11 @@ export default {
       app.inject(t, "session", "session:main");
       app.inject(t, "messageBus", "message-bus:main");
       app.inject(t, "siteSettings", "site-settings:main");
+      app.inject(t, "topicTrackingState", "topic-tracking-state:main");
     });
 
     if (currentUser) {
-      ["component", "route", "controller", "service"].forEach((t) => {
+      ["controller", "component", "route", "service"].forEach((t) => {
         app.inject(t, "currentUser", "current-user:main");
       });
     }

app/assets/javascripts/discourse/app/services/screen-track.js

@@ -1,3 +1,4 @@
+import Service, { inject as service } from "@ember/service";
 import { ajax } from "discourse/lib/ajax";
 import { bind } from "discourse-common/utils/decorators";
 import { isTesting } from "discourse-common/config/environment";
@@ -10,21 +11,24 @@ const ANON_MAX_TOPIC_IDS = 5;
 const AJAX_FAILURE_DELAYS = [5000, 10000, 20000, 40000];
 const ALLOWED_AJAX_FAILURES = [405, 429, 500, 501, 502, 503, 504];
 
-export default class {
-  constructor(
-    topicTrackingState,
-    siteSettings,
-    session,
-    currentUser,
-    appEvents
-  ) {
-    this.topicTrackingState = topicTrackingState;
-    this.siteSettings = siteSettings;
-    this.session = session;
-    this.currentUser = currentUser;
-    this.appEvents = appEvents;
+export default class ScreenTrack extends Service {
+  @service appEvents;
+
+  _consolidatedTimings = [];
+  _lastTick = null;
+  _lastScrolled = null;
+  _lastFlush = 0;
+  _timings = {};
+  _totalTimings = {};
+  _topicTime = 0;
+  _onscreen = [];
+  _readOnscreen = [];
+  _readPosts = {};
+  _inProgress = false;
+
+  constructor() {
+    super(...arguments);
     this.reset();
-    this._consolidatedTimings = [];
   }
 
   start(topicId, topicController) {

app/assets/javascripts/discourse/tests/unit/controllers/topic-test.js

@@ -17,11 +17,10 @@ function topicWithStream(streamDetails) {
 
 discourseModule("Unit | Controller | topic", function (hooks) {
   hooks.beforeEach(function () {
-    this.registry.register("service:screen-track", {}, { instantiate: false });
     this.registry.injection("controller", "appEvents", "service:app-events");
   });
+
   hooks.afterEach(function () {
-    this.registry.unregister("service:screen-track");
     this.registry.unregister("current-user:main");
     let topic = this.container.lookup("controller:topic");
     topic.setProperties({

app/assets/javascripts/discourse/tests/unit/services/screen-track-test.js

@@ -1,9 +1,9 @@
-import { module, test } from "qunit";
-import ScreenTrack from "discourse/lib/screen-track";
+import { discourseModule } from "discourse/tests/helpers/qunit-helpers";
+import { test } from "qunit";
 
-module("Unit | Utility | screen-track", function () {
+discourseModule("Unit | Service | screen-track", function () {
   test("consolidateTimings", function (assert) {
-    const tracker = new ScreenTrack();
+    const tracker = this.container.lookup("service:screen-track");
 
     tracker.consolidateTimings({ 1: 10, 2: 5 }, 10, 1);
     tracker.consolidateTimings({ 1: 5, 3: 1 }, 3, 1);