AG-16874 fix EventTracker

Squashed commit of the following:

commit 3ec9b65dd598735bf695db05ecedb0f82ea68b94
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Tue Oct 11 15:17:07 2022 +0300

    no extra type definition for applyRulesCallbackListener

commit 1ea678ea52366f63ee0de086de8d40dc58dc3cc4
Merge: 94dd26b e8286b1
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Tue Oct 11 12:06:58 2022 +0300

    Merge branch 'epic/AG-3532' into fix/AG-16874

commit 94dd26b7f3be35088e4de6bbb76c17676c9d6112
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Mon Oct 10 15:46:14 2022 +0300

    remove event listener while ExtendedCss.dispose()

commit fa99b5c7d90c20b1606128adc712c966b35295fb
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Mon Oct 10 15:38:02 2022 +0300

    remove eventTracker listeners on main document observer disconnect

commit 1ca59ee9795a4a2bea6a6aa9d6278eded5c31545
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Fri Oct 7 15:33:01 2022 +0300

    remove unused private lastEvent

src/extended-css/extended-css.ts

@@ -91,6 +91,8 @@ export class ExtendedCss {
 
     private applyRulesScheduler: AsyncWrapper;
 
+    private applyRulesCallbackListener: () => void;
+
     // Instance of ExtCssDocument is needed for using selector-ast cache
     extCssDocument: ExtCssDocument;
 
@@ -128,6 +130,10 @@ export class ExtendedCss {
         if (this.context.beforeStyleApplied && typeof this.context.beforeStyleApplied !== 'function') {
             throw new Error(`Invalid configuration. Type of 'beforeStyleApplied' should be a function, received: '${typeof this.context.beforeStyleApplied}'`); // eslint-disable-line max-len
         }
+
+        this.applyRulesCallbackListener = () => {
+            applyRules(this.context);
+        };
     }
 
     /**
@@ -139,7 +145,7 @@ export class ExtendedCss {
         if (document.readyState !== 'complete') {
             document.addEventListener(
                 'DOMContentLoaded',
-                () => { applyRules(this.context); },
+                this.applyRulesCallbackListener,
                 false,
             );
         }
@@ -153,6 +159,11 @@ export class ExtendedCss {
         this.context.affectedElements.forEach((el) => {
             revertStyle(el);
         });
+        document.removeEventListener(
+            'DOMContentLoaded',
+            this.applyRulesCallbackListener,
+            false,
+        );
     }
 
     /**

src/extended-css/helpers/document-observer.ts

@@ -22,6 +22,9 @@ const observeDocument = (context: Context, callback: MainCallback): void => {
             if (eventTracker.isIgnoredEventType() && shouldIgnoreMutations(mutations)) {
                 return;
             }
+            // save instance of EventTracker to context
+            // for removing its event listeners on disconnectDocument() while mainDisconnect()
+            context.eventTracker = eventTracker;
             callback();
         }));
         context.domMutationObserver.observe(document, {
@@ -45,6 +48,8 @@ const disconnectDocument = (context: Context, callback: MainCallback): void => {
         document.removeEventListener('DOMNodeRemoved', callback, false);
         document.removeEventListener('DOMAttrModified', callback, false);
     }
+    // clean up event listeners
+    context.eventTracker?.stopTracking();
 };
 
 export const mainObserve = (context: Context, mainCallback: MainCallback): void => {

src/extended-css/helpers/event-tracker.ts

@@ -25,8 +25,6 @@ const SAFARI_PROBLEMATIC_EVENTS = ['wheel'];
 export class EventTracker {
     private trackedEvents: string[];
 
-    private lastEvent?: Event;
-
     private lastEventType?: string;
 
     private lastEventTime?: number;
@@ -42,7 +40,6 @@ export class EventTracker {
     }
 
     private trackEvent(event: Event): void {
-        this.lastEvent = event;
         this.lastEventType = event.type;
         this.lastEventTime = Date.now();
     }
@@ -64,4 +61,10 @@ export class EventTracker {
             && !!sinceLastEventTime
             && sinceLastEventTime < LAST_EVENT_TIMEOUT_MS;
     }
+
+    stopTracking(): void {
+        this.trackedEvents.forEach((eventName) => {
+            document.documentElement.removeEventListener(eventName, this.trackEvent, true);
+        });
+    }
 }

src/extended-css/helpers/types.ts

@@ -1,4 +1,5 @@
 import { CssStyleMap, ExtCssRuleData } from '../../stylesheet';
+import { EventTracker } from './event-tracker';
 import { ExtMutationObserver } from './mutation-observer';
 
 export type MainCallback = () => void;
@@ -78,6 +79,11 @@ export interface Context {
      */
     isDomObserved: boolean;
 
+    /**
+     * Instance of EventTracker for document observing
+     */
+    eventTracker?: EventTracker;
+
     /**
      * Main document mutation observer
      */