CROSSORIGIN, CREDENTIALS, PRIORITY and ACCEPT MIME

[giorgiopellegrino]

Dear @addyosmani @XhmikosR ,

I am submitting this pull request to address issues encountered within our Luxottica e-commerce group, where we observed inconsistent resource prefetching behavior across different browsers.

Currently, three prefetching methods are implemented:

1. viaDom – Prefetches resources without checking the Access-Control-Allow-Origin header, using the attribute crossorigin="anonymous".
2. viaXhr – Fetches resources while always validating the Access-Control-Allow-Credentials response header.
3. viaFetch – Executes a fetch request that defaults to mode: "cors" and checks Access-Control-Allow-Origin, while credentials: "include" ensures Access-Control-Allow-Credentials validation.

Additionally, I have handled resource prioritization for Safari devices, adding the priority: "low|high" property specifically for fetch requests. All parameters are set to false by default but can be adjusted as needed.

The updated method signature for prefetching is as follows:

prefetch(url, isPriority, checkAccessControlAllowOrigin, checkAccessControlAllowCredentials)

I would appreciate your review of these improvements.

Thank you,
Giorgio

c.c. @gilbertococchi

[giorgiopellegrino]

Hello @addyosmani ,

I noticed that the code in the pull request did not pass the size limit test. Could you consider increass the size limits? The increase in resource size is due to the introduction of new arguments and parameters.

Thank you,
Giorgio