Adding HTTP method to ResourceTiming API structure

[sohomdatta1]

The ResourceTiming API structure doesn't currently give us insight into what HTTP method was used to fetch a specific resource and/or make a API call. It would be great if the HTTP method used to make a specific HTTP request could be added to the ResourceTiming structure.

The major usecase where I see this getting used (and from where this idea came from) is to debug cases where a POST request would have additional latency/overhead over a GET request or vice-versa.

[yoavweiss]

^^ @nicjansma

[clelland]

Let's add this to the agenda for the WG for discussion this week

[nicjansma]

Yes this seems very useful for being able to segment the performance of URLs that are used with different methods. REST APIs come to mind here.

[nicjansma]

For posterity, we had discussed this on the April 13th, 2023 W3C WebPerf Working Group call.

Notes @ https://docs.google.com/document/d/1fIgfd7ONz-sES55qRFHQI_eQUnynnyX2Asrs-cwAQ_Q/edit#heading=h.nuc3bt9j96hk

Summary:

• Useful to know whether a HTTP request was a GET/POST/etc from ResourceTiming, as they may have different performance characteristics
• Question if this would be covered by CORS, or would need another opt-in
• Next steps: Getting a security review from security folks at each vendor