do not inject cosmetic rules into an assistant frame. AG-9829

AdguardTeam/AdguardBrowserExtension#1848

Squashed commit of the following:

commit 7dd337d
Author: Slava Leleka <[email protected]>
Date:   Mon Mar 25 15:50:34 2024 +0300

    packages/tswebextension/CHANGELOG.md edited online with Bitbucket

commit d572159
Author: Slava Leleka <[email protected]>
Date:   Fri Mar 22 19:19:23 2024 +0200

    decrease Assistant.FRAME_CREATION_LIMIT_MS to 100

commit 60ef472
Author: Slava Leleka <[email protected]>
Date:   Fri Mar 22 19:13:18 2024 +0200

    add url checking

commit 0f3c5c1
Author: Slava Leleka <[email protected]>
Date:   Fri Mar 22 17:50:33 2024 +0200

    make isAssistantFrame() a static method of Assistant

commit c1b3ebf
Author: Slava Leleka <[email protected]>
Date:   Fri Mar 22 16:31:08 2024 +0200

    fix setAssistantInitTimestamp()

commit bfed0f7
Author: Slava Leleka <[email protected]>
Date:   Thu Mar 21 21:25:18 2024 +0200

    do not inject cosmetic rules into an assistant frame

packages/tswebextension/CHANGELOG.md

@@ -8,6 +8,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 <!-- TODO: manually add compare links for version changes -->
 <!-- e.g. [0.1.2]: https://github.com/AdguardTeam/tsurlfilter/compare/tswebextension-v0.1.1...tswebextension-v0.1.2 -->
 
+## [1.0.17] - 2024-03-25
+
+### Fixed
+
+- Assistant iframe styles are affected by cosmetic rules specific for websites [AdguardBrowserExtension#1848].
+
+[1.0.17]: https://github.com/AdguardTeam/tsurlfilter/releases/tag/tswebextension-v1.0.17
+[AdguardBrowserExtension#1848]: https://github.com/AdguardTeam/AdguardBrowserExtension/issues/1848
+
+
 ## [1.0.16] - 2024-03-01
 
 ### Changed

packages/tswebextension/src/lib/common/app.ts

@@ -49,6 +49,8 @@ export interface AppInterface<
 
     /**
      * Launches assistant in the current tab.
+     *
+     * @param tabId Id of the tab to launch assistant in.
      */
     openAssistant: (tabId: number) => void;
 

packages/tswebextension/src/lib/mv2/background/app.ts

@@ -212,6 +212,7 @@ MessageHandlerMV2
      * @param tabId Tab id where assistant will be opened.
      */
     public async openAssistant(tabId: number): Promise<void> {
+        this.tabsApi.setAssistantInitTimestamp(tabId);
         await Assistant.openAssistant(tabId);
     }
 
@@ -221,6 +222,7 @@ MessageHandlerMV2
      * @param tabId Tab id.
      */
     public async closeAssistant(tabId: number): Promise<void> {
+        this.tabsApi.resetAssistantInitTimestamp(tabId);
         await Assistant.closeAssistant(tabId);
     }
 

packages/tswebextension/src/lib/mv2/background/assistant.ts

@@ -1,11 +1,22 @@
-import browser from 'webextension-polyfill';
+import browser, { WebNavigation } from 'webextension-polyfill';
 import { EventChannel, MessageType } from '../../common';
 import { messagesApi } from './api';
+import { MAIN_FRAME_ID, TabContext } from './tabs';
 
 /**
- * Event channel wrapper for sending messages to assistant.
+ * Event channel wrapper for sending messages to the assistant.
  */
 export class Assistant {
+    /**
+     * Maximum time delay in milliseconds between the assistant frame creation and the assistant initialization.
+     */
+    private static FRAME_CREATION_LIMIT_MS = 100;
+
+    /**
+     * Assistant frame URL.
+     */
+    private static FRAME_URL = 'about:blank';
+
     public static onCreateRule = new EventChannel<string>();
 
     /**
@@ -43,4 +54,41 @@ export class Assistant {
             type: MessageType.CloseAssistant,
         });
     }
+
+    /**
+     * Checks whether the frame is an assistant frame. Two conditions must be met:
+     * 1. The frame was created less than {@link Assistant.FRAME_CREATION_LIMIT_MS} milliseconds
+     *    after the assistant initialization.
+     * 2. The frame is a child of the main frame.
+     *
+     * @see {@link https://github.com/AdguardTeam/AdguardBrowserExtension/issues/1848}
+     *
+     * @param details Frame details of the onDomContentLoaded event.
+     * @param tabContext Tab context.
+     *
+     * @returns True if the frame is an assistant frame, false otherwise.
+     */
+    public static async isAssistantFrame(
+        details: WebNavigation.OnDOMContentLoadedDetailsType,
+        tabContext: TabContext | undefined,
+    ): Promise<boolean> {
+        if (!tabContext || !tabContext?.assistantInitTimestamp) {
+            return false;
+        }
+
+        const {
+            tabId,
+            url,
+            frameId,
+            timeStamp,
+        } = details;
+
+        const newFrameData = await browser.webNavigation.getFrame({ tabId, frameId });
+
+        const timeSinceFrameCreatedMs = timeStamp - tabContext.assistantInitTimestamp;
+
+        return timeSinceFrameCreatedMs < Assistant.FRAME_CREATION_LIMIT_MS
+            && url === Assistant.FRAME_URL
+            && newFrameData?.parentFrameId === MAIN_FRAME_ID;
+    }
 }

packages/tswebextension/src/lib/mv2/background/tabs/tab-context.ts

@@ -63,6 +63,15 @@ export class TabContext {
      */
     public isDocumentRequestCached = false;
 
+    /**
+     * Timestamp of the assistant initialization.
+     *
+     * Needed to avoid cosmetic rules injection into the assistant frame.
+     *
+     * @see {@link https://github.com/AdguardTeam/AdguardBrowserExtension/issues/1848}
+     */
+    public assistantInitTimestamp?: number | null = null;
+
     /**
      * Context constructor.
      *

packages/tswebextension/src/lib/mv2/background/tabs/tabs-api.ts

@@ -208,6 +208,38 @@ export class TabsApi {
         return this.context.get(tabId);
     }
 
+    /**
+     * Sets a current timestamp as `assistantInitTimestamp` of the tab context.
+     *
+     * Needed to determine later if a newly created frame is an assistant frame.
+     *
+     * @param tabId Tab id.
+     */
+    public setAssistantInitTimestamp(tabId: number): void {
+        const tabContext = this.context.get(tabId);
+
+        if (!tabContext) {
+            return;
+        }
+
+        tabContext.assistantInitTimestamp = Date.now();
+    }
+
+    /**
+     * Resets tab context's `assistantInitTimestamp` to null.
+     *
+     * @param tabId Tab id.
+     */
+    public resetAssistantInitTimestamp(tabId: number): void {
+        const tabContext = this.context.get(tabId);
+
+        if (!tabContext) {
+            return;
+        }
+
+        tabContext.assistantInitTimestamp = null;
+    }
+
     /**
      * Checks whether the tab with the specified ID is open in incognito mode
      * or not.

packages/tswebextension/src/lib/mv2/background/web-request-api.ts

@@ -179,6 +179,7 @@ import { logger } from '../../common/utils/logger';
 import { defaultFilteringLog, FilteringEventType } from '../../common/filtering-log';
 import { FRAME_DELETION_TIMEOUT } from '../../common/constants';
 
+import { Assistant } from './assistant';
 import { CosmeticApi } from './cosmetic-api';
 import { headersService } from './services/headers-service';
 import { paramsService } from './services/params-service';
@@ -717,7 +718,7 @@ export class WebRequestApi {
      * @see https://github.com/AdguardTeam/AdguardBrowserExtension/issues/1046
      * @param details Event details.
      */
-    private static onDomContentLoaded(details: WebNavigation.OnDOMContentLoadedDetailsType): void {
+    private static async onDomContentLoaded(details: WebNavigation.OnDOMContentLoadedDetailsType): Promise<void> {
         const {
             tabId,
             frameId,
@@ -732,6 +733,13 @@ export class WebRequestApi {
             return;
         }
 
+        const isAssistant = await Assistant.isAssistantFrame(details, tabContext);
+
+        // do not inject cosmetic rules into the assistant frame
+        if (isAssistant) {
+            return;
+        }
+
         const cosmeticResult = engineApi.matchCosmetic({
             requestUrl: mainFrameUrl,
             frameUrl: mainFrameUrl,