1 files changed, 16 insertions, 0 deletions
diff --git a/ext/js/extension/web-extension.js b/ext/js/extension/web-extension.js
index 2aafbe92..bdc9b1b3 100644
--- a/ext/js/extension/web-extension.js
+++ b/ext/js/extension/web-extension.js
@@ -26,6 +26,13 @@ export class WebExtension extends EventDispatcher {
         super();
         /** @type {boolean} */
         this._unloaded = false;
+        /** @type {?string} */
+        this._extensionBaseUrl = null;
+        try {
+            this._extensionBaseUrl = this.getUrl('/');
+        } catch (e) {
+            // NOP
+        }
     }
 
     /** @type {boolean} */
@@ -105,4 +112,13 @@ export class WebExtension extends EventDispatcher {
         this._unloaded = true;
         this.trigger('unloaded', {});
     }
+
+    /**
+     * Checks whether or not a URL is an extension URL.
+     * @param {string} url The URL to check.
+     * @returns {boolean} `true` if the URL is an extension URL, `false` otherwise.
+     */
+    isExtensionUrl(url) {
+        return this._extensionBaseUrl !== null && url.startsWith(this._extensionBaseUrl);
+    }
 }