multipleResolves event emitted for Promise.race()

[mcollina]

For 'multipleResolves' to be useful in debugging scenarios, we should treat it as an error-like condition. However, Promise.race() implementation triggers it:

process.on('multipleResolves', function () {
  console.log('multipleResolves', arguments)
  // currently prints:
  // multipleResolves [Arguments] { '0': 'resolve', '1': Promise { 'a' }, '2': 'b' }
})

Promise.race([Promise.resolve('a'), Promise.resolve('b')])

I would recommend we change Promise.race()  implementation in V8 to only call resolve once. Would it be something that could be landed in V8?

cc @benjamingr @BridgeAR @bmeurer @nodejs/v8 @nodejs/promises-debugging

Originally reported as mcollina/make-promises-safe#12.

• Version: 10.13.0
• Platform: all
• Subsystem: Promise

[bmeurer]

This seems like a duplicate of #24321

[devsnek]

race/all only calling resolve/reject once would be visible to someone doing Promise.race.call(notPromise) (and break the spec)

[devsnek]

Duplicate of #24321