From a80b3ddb4a938adb4054938bb7550fecb546e2a7 Mon Sep 17 00:00:00 2001
From: Xinyi Ye <xinyi.ye@amplitude.com>
Date: Tue, 17 Dec 2024 16:19:42 -0800
Subject: [PATCH] fix: should default to empty string when document.title is
 not string

---
 .../src/page-view-tracking.ts                 | 21 ++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/packages/plugin-page-view-tracking-browser/src/page-view-tracking.ts b/packages/plugin-page-view-tracking-browser/src/page-view-tracking.ts
index a985c69a6..655f38f4f 100644
--- a/packages/plugin-page-view-tracking-browser/src/page-view-tracking.ts
+++ b/packages/plugin-page-view-tracking-browser/src/page-view-tracking.ts
@@ -34,6 +34,25 @@ export const pageViewTrackingPlugin: CreatePageViewTrackingPlugin = (options: Op
     return decodedLocationStr;
   };
 
+  /* istanbul ignore next */
+  const getDocumentTitle = () => {
+    if (typeof document === 'undefined') {
+      localConfig?.loggerProvider.warn('document is undefined. Default [Amplitude] Page Title to an empty string');
+      return '';
+    }
+
+    const title = document.title;
+    if (typeof title !== 'string') {
+      localConfig?.loggerProvider.warn(
+        // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
+        `document.title is not a string. Default [Amplitude] Page Title to an empty string. document.title: ${title}`,
+      );
+      return '';
+    }
+
+    return title;
+  };
+
   const createPageViewEvent = async (): Promise<Event> => {
     /* istanbul ignore next */
     const locationHREF = getDecodeURI((typeof location !== 'undefined' && location.href) || '');
@@ -46,7 +65,7 @@ export const pageViewTrackingPlugin: CreatePageViewTrackingPlugin = (options: Op
         '[Amplitude] Page Location': locationHREF,
         '[Amplitude] Page Path':
           /* istanbul ignore next */ (typeof location !== 'undefined' && getDecodeURI(location.pathname)) || '',
-        '[Amplitude] Page Title': /* istanbul ignore next */ (typeof document !== 'undefined' && document.title) || '',
+        '[Amplitude] Page Title': getDocumentTitle(),
         '[Amplitude] Page URL': locationHREF.split('?')[0],
       },
     };