Developing Web Application Firewall for Single Page Application?

Question

firewall

Area: information security. I am doing research on SinglePageAplication (SPA) from a security point of view to find new types of vulnerabilities for further development of Web Application Firewall (WAF).
When studying SPA, I did not notice specific threats (I read several books on their development). I am also not familiar with the development of WAF, I am going to study their approaches for classic applications first.
I ask the professional community to suggest ways of development, especially for SPA research, materials (books, articles) for further study.
ps noticed that in PHDAYS 2015 YOUNG SCHOOL one of the topics of the reports "search and bypass vulnerabilities in modern single page applications" was proposed, but did not find any results.