Fix uncached video bids triggering callback early

[matthewlane]

Type of change

• Bugfix

Description of change

Fixes a bug where auctions for video bids with cache enabled would execute the prebid callback handler on the first bid response, rather than waiting for all bids to be back. Does this by marking the doneCbCallCount property of cach-enabled video bids only after they've been cached server-side, rather than immediately on bid response.

To test manually, create a test page with the following ad unit ('appnexusAst' is an alias of 'appnexus'). On master, search for auctionEnd in the dev console and notice a bidResponse comes after this event. On this fix, auctionEnd comes after all bidResponses

pbjs.setConfig({
  debug: true,
  cache: {
    url: 'https://prebid.adnxs.com/pbc/v1/cache'
  },
});

pbjs.addAdUnits({
  code: '/19968336/prebid_video_adunit',
  sizes: [[640,480]],
  mediaTypes: { video: {context: 'instream'} },
  bids: [
    {
      bidder: 'appnexusAst',
      params: {
        placementId: '9333431',
        video: { skippable: true, playback_method: ['auto_play_sound_off'] }
      }
    },
    {
      bidder: 'appnexus',
      params: {
        placementId: '9333431',
        video: { skippable: true, playback_method: ['auto_play_sound_off'] }
      }
    },
  ]
});

[mkendall07]

lgtm

[jsnellbaker]

LGTM