This repo contains an express app that simulates impact of SameSite cookie attribute on various scenarios involving iframing content.
In order to use this, you need to add the following lines to your hosts file
127.0.0.1 org.fakemaps.fakegis.com
127.0.0.1 www.fakegis.com
127.0.0.1 site-org.fakehub.fakegis.com
127.0.0.1 fake.customdomain.com
Run npm start, and then open http://site-org.fakehub.fakegis.com:3000 in Chrome.
If you want to explore how this will work when Chrome 80 lands, and starts treating all cookies without a SameSite attribute as SameSite=Lax, then enable the "SameSite by default cookies" flag, availabe at chrome://flags/