How to properly protect against xss?

Question

JavaScript

Good afternoon. I read a lot of articles about protection against xss, but specific cases are considered everywhere, there is no fundamental article that describes absolutely all the possibilities for an attack. The situation looks like everyone knows how to write a defense, but no one shares)
Give a link to such an article if I'm wrong :)
Thank you

Answer 1

There is no universal tablet. There are general principles that are usually shown in the examples that you criticize.
To put it bluntly: filter and check data you don't trust.
Further, only particulars and examples, but you don’t like them.

Answer 2

Look how it's done in good frameworks. You pass input data through validators, output data through a purifier, queries to the database through prepared.

Answer 3

Use HTTP security headers
https://kostikov.co/post/zagolovki-http-i-bezopasn...