Access to ID of the auction won by cached bid in BID_WON event

[msmeza]

Type of issue

Feature request

Description

As far as I can see, there's no direct way of finding the ID of an auction won by a cached bid through BID_WON events; the bids included in the events only contain the ID of their original auctions.

Ideally, we'd like to be able to find the ID of the auction won by a cached bid directly from the data included in a BID_WON event, to be able to map them using only the data received from our analytics adapter.

Other information

I searched the list of issues and I do not believe that this has been brought up before, though I did find an issue where there's a mention of multiple winning bids with the same auction ID coming from an analytics adapter, which can happen when cached bids win auctions (#6411). However, this issue seems to be more about finding the actual winner of an auction ID with multiple winners, rather than identifying the auction IDs of auctions won by cached bids.

We believe that being able to map winning cached bids with the auctions that they actually won would be useful for others as well. For example, if I understood the code correclty, Magnite seems to have a function to try and do that in their analytics adapter (getRenderingIds).

I'm sure there are better ways to achieve our goal, but I submitted a PR with a way of doing it to help with the discussion (#10541).