es-module-shims makes request to browser internal data (blob:...) requiring specific CSP policy

[jean553]

By loading the library, we can see the browser making some requests to cached data stored on the browser memory: blob:https://our-domain/....

This request is made from es-module-shims.js.

We have very strict CSP policies. Is this call to cache really necessary and is there a way to disable it ?

[guybedford]

Yes, this is necessary, as that is how the polyfill operates in rewriting the specifiers using blob URLs.