Drop non-video bidders from video ad units

[matthewlane]

Type of change

• Bugfix

Description of change

Ad units with mediaType: 'video' that included non-video bidders were preventing calls to all bidders in the ad unit, even if that included video bidders. This change drops non-video bidders and still calls valid video bidders rather than dropping the ad unit entirely. Works for ad units configured with mediaTypes: 'video' or 1.0-compatible meidaTypes: {video: {}}

In this example ad unit, on master appnexusAst will not get called because fakeBidder is not a video bidder, or even real for that matter. With this PR appnexusAst gets called.

pbjs.addAdUnits({
  code: '/19968336/prebid_video_adunit',
  sizes: [640,480],
  mediaType: 'video',
  // or mediaTypes: { video: {context: 'instream'} },
  bids: [

    {
      bidder: 'appnexusAst',
      params: {
        placementId: '9333431',
        video: { skippable: true, playback_method: ['auto_play_sound_off'] }
      }
    },

    {
      bidder: 'fakeBidder',
      params: { tag: 'stopHammerTime' }
    },

  ]
});

Other information

Fixes #1137

[mkendall07]

I'd prefer that we call the demand that is enabled for video instead of just dropping it completely. Is it hard to make that change?

[matthewlane]

Yeah that makes sense, I can do it. I'll update the PR to do that when either mediaType or mediaTypes is used to configure 'video'