PAAPI: example page and perBuyerSignals bad key + FPD module error

[piotrj-rtbh]

Type of issue

Possibly a bug in topLevelPaapi or paapi modules.
Error in FPD module topics.

Description

The runAdAuction log contains componentAuctions with wrong perBuyerSignals key being a domain split by dot (.)
Yet another error found in the console:

ERROR: Error in FPD module topics TypeError: Cannot read properties of undefined (reading 'bidders')

Steps to reproduce

• Start local server with:

gulp serve-fast --https

• Run Chrome with flags:

--enable-features=CookieDeprecationFacilitatedTesting:label/treatment_1.2/force_eligible/true --privacy-sandbox-enrollment-overrides=https://localhost:9999

• Join interest group at https://www.optable.co/

Visit https://localhost:9999/integrationExamples/top-level-paapi/no_adserver.html

In the browser's console find runAdAuction and expand the Object's tree: componentAuctions[0].perBuyerSignals.

Test page

https://localhost:9999/integrationExamples/top-level-paapi/no_adserver.html

Expected results

perBuyerSignals: { "https://ads.optable.co": { prebid: {...}}}

No error from FPD module.

Actual results

Platform details

Prebid.js: current master branch (currently 9.2.0-pre)
Browser: Chrome Version 126.0.6478.63 (Official Build) (64-bit)
OS: Ubuntu 20.04.6 LTS
Node v18.18.2
NPM: 9.8.1

Other information

#11379
@dgirardi

[piotrj-rtbh]

@dgirardi The following line in the paapi module makes the key in perBuyerSignals be split by dot:

Prebid.js/modules/paapi.js

Line 162 in 0668544

deepSetValue(config, `perBuyerSignals.${buyer}`, setFPD(config.perBuyerSignals?.[buyer] || {}, request));