3 files changed, 31 insertions, 27 deletions

diff --git a/ext/js/comm/cross-frame-api.js b/ext/js/comm/cross-frame-api.js
index 4b4e9419..33a91c89 100644
--- a/ext/js/comm/cross-frame-api.js
+++ b/ext/js/comm/cross-frame-api.js
@@ -313,6 +313,20 @@ export class CrossFrameAPI {
         this._frameId = frameId;
     }
 
+    /**
+     * @type {?number}
+     */
+    get tabId() {
+        return this._tabId;
+    }
+
+    /**
+     * @type {?number}
+     */
+    get frameId() {
+        return this._frameId;
+    }
+
     /** */
     prepare() {
         chrome.runtime.onConnect.addListener(this._onConnect.bind(this));
diff --git a/ext/js/comm/frame-ancestry-handler.js b/ext/js/comm/frame-ancestry-handler.js
index 3e58d57b..92ed3b8c 100644
--- a/ext/js/comm/frame-ancestry-handler.js
+++ b/ext/js/comm/frame-ancestry-handler.js
@@ -28,13 +28,10 @@ export class FrameAncestryHandler {
     /**
      * Creates a new instance.
      * @param {import('../comm/cross-frame-api.js').CrossFrameAPI} crossFrameApi
-     * @param {number} frameId The frame ID of the current frame the instance is instantiated in.
      */
-    constructor(crossFrameApi, frameId) {
+    constructor(crossFrameApi) {
         /** @type {import('../comm/cross-frame-api.js').CrossFrameAPI} */
         this._crossFrameApi = crossFrameApi;
-        /** @type {number} */
-        this._frameId = frameId;
         /** @type {boolean} */
         this._isPrepared = false;
         /** @type {string} */
@@ -48,14 +45,6 @@ export class FrameAncestryHandler {
     }
 
     /**
-     * Gets the frame ID that the instance is instantiated in.
-     * @type {number}
-     */
-    get frameId() {
-        return this._frameId;
-    }
-
-    /**
      * Initializes event event listening.
      */
     prepare() {
@@ -116,8 +105,9 @@ export class FrameAncestryHandler {
      */
     _getFrameAncestryInfo(timeout = 5000) {
         return new Promise((resolve, reject) => {
+            const {frameId} = this._crossFrameApi;
             const targetWindow = window.parent;
-            if (window === targetWindow) {
+            if (frameId === null || window === targetWindow) {
                 resolve([]);
                 return;
             }
@@ -141,11 +131,10 @@ export class FrameAncestryHandler {
                 if (params.nonce !== nonce) { return null; }
 
                 // Add result
-                const {frameId, more} = params;
-                results.push(frameId);
+                results.push(params.frameId);
                 nonce = generateId(16);
 
-                if (!more) {
+                if (!params.more) {
                     // Cleanup
                     cleanup();
 
@@ -167,7 +156,6 @@ export class FrameAncestryHandler {
             // Start
             this._addResponseHandler(uniqueId, onMessage);
             resetTimeout();
-            const frameId = this._frameId;
             this._requestFrameInfo(targetWindow, frameId, frameId, uniqueId, nonce);
         });
     }
@@ -208,7 +196,9 @@ export class FrameAncestryHandler {
                 return;
             }
 
-            const frameId = this._frameId;
+            const {frameId} = this._crossFrameApi;
+            if (frameId === null) { return; }
+
             const {parent} = window;
             const more = (window !== parent);
 
diff --git a/ext/js/comm/frame-offset-forwarder.js b/ext/js/comm/frame-offset-forwarder.js
index fe1ff98a..59659606 100644
--- a/ext/js/comm/frame-offset-forwarder.js
+++ b/ext/js/comm/frame-offset-forwarder.js
@@ -21,15 +21,12 @@ import {FrameAncestryHandler} from './frame-ancestry-handler.js';
 export class FrameOffsetForwarder {
     /**
      * @param {import('../comm/cross-frame-api.js').CrossFrameAPI} crossFrameApi
-     * @param {number} frameId
      */
-    constructor(crossFrameApi, frameId) {
+    constructor(crossFrameApi) {
         /** @type {import('../comm/cross-frame-api.js').CrossFrameAPI} */
         this._crossFrameApi = crossFrameApi;
-        /** @type {number} */
-        this._frameId = frameId;
         /** @type {FrameAncestryHandler} */
-        this._frameAncestryHandler = new FrameAncestryHandler(crossFrameApi, frameId);
+        this._frameAncestryHandler = new FrameAncestryHandler(crossFrameApi);
     }
 
     /**
@@ -50,15 +47,18 @@ export class FrameOffsetForwarder {
             return [0, 0];
         }
 
+        const {frameId} = this._crossFrameApi;
+        if (frameId === null) { return null; }
+
         try {
             const ancestorFrameIds = await this._frameAncestryHandler.getFrameAncestryInfo();
 
-            let childFrameId = this._frameId;
+            let childFrameId = frameId;
             /** @type {Promise<?import('frame-offset-forwarder').ChildFrameRect>[]} */
             const promises = [];
-            for (const frameId of ancestorFrameIds) {
-                promises.push(this._crossFrameApi.invoke(frameId, 'frameOffsetForwarderGetChildFrameRect', {frameId: childFrameId}));
-                childFrameId = frameId;
+            for (const ancestorFrameId of ancestorFrameIds) {
+                promises.push(this._crossFrameApi.invoke(ancestorFrameId, 'frameOffsetForwarderGetChildFrameRect', {frameId: childFrameId}));
+                childFrameId = ancestorFrameId;
             }
 
             const results = await Promise.all(promises);