It's debatable whether some of the data files needed to be version controlled.

[ttzeng]

Files checked in GitHub repositories are version controlled, but it may not be necessary to keep version history of some of database files (e.g. broken icon links, or increased BKM). The following are data files referenced by this github.io code:

• ./json/*.json
• ./files/tips/*.*

[ttzeng]

The following CORS error was shown while trying to move one JSON file as a file object on GCP storage:

Access to XMLHttpRequest at 'https://storage.cloud.google.com/ttzeng-github-io-data/tips.json' from origin 'http://127.0.0.1:5500' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.<br>
Failed to load resource: net::ERR_FAILED

[ttzeng]

After sending the request with "Access-Control-Allow-Origin : *" header, the error indicates the preflight request is not allowed:

Access to XMLHttpRequest at 'https://storage.cloud.google.com/ttzeng-github-io-data/tips.json' from origin 'http://127.0.0.1:5500' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: Redirect is not allowed for a preflight request.
GET https://storage.cloud.google.com/ttzeng-github-io-data/tips.json net::ERR_FAILED

[ttzeng]

This article articulates 3 ways to fix the CORS error.