Media type renderers

src/auction.js

@@ -512,9 +512,26 @@ function getPreparedBidForAuction({adUnitCode, bid, bidderRequest, auctionId}) {
   const bidReq = bidderRequest.bids && find(bidderRequest.bids, bid => bid.adUnitCode == adUnitCode);
   const adUnitRenderer = bidReq && bidReq.renderer;
 
-  if (adUnitRenderer && adUnitRenderer.url && !(adUnitRenderer.backupOnly && isBoolean(adUnitRenderer.backupOnly) && bid.renderer)) {
-    bidObject.renderer = Renderer.install({ url: adUnitRenderer.url });
-    bidObject.renderer.setRender(adUnitRenderer.render);
+  // a publisher can also define a renderer for a mediaType
+  const bidObjectMediaType = bidObject.mediaType;
+  const bidMediaType = bidReq &&
+        bidReq.mediaTypes &&
+        bidReq.mediaTypes[bidObjectMediaType];
+
+  var mediaTypeRenderer = bidMediaType && bidMediaType.renderer;
+
+  var renderer = null;
+
+  // the renderer for the mediaType takes precendence
+  if (mediaTypeRenderer && mediaTypeRenderer.url && mediaTypeRenderer.render) {
+    renderer = mediaTypeRenderer;
+  } else if (adUnitRenderer && adUnitRenderer.url && !(adUnitRenderer.backupOnly && isBoolean(adUnitRenderer.backupOnly) && bid.renderer)) {
+    renderer = adUnitRenderer;
+  }
+
+  if (renderer) {
+    bidObject.renderer = Renderer.install({ url: renderer.url });
+    bidObject.renderer.setRender(renderer.render);
   }
 
   // Use the config value 'mediaTypeGranularity' if it has been defined for mediaType, else use 'customPriceBucket'

src/video.js

@@ -59,7 +59,7 @@ export const checkVideoBidSetup = hook('sync', function(bid, bidRequest, videoMe
 
   // outstream bids require a renderer on the bid or pub-defined on adunit
   if (context === OUTSTREAM) {
-    return !!(bid.renderer || bidRequest.renderer);
+    return !!(bid.renderer || bidRequest.renderer || videoMediaType.renderer);
   }
 
   return true;

test/spec/auctionmanager_spec.js

@@ -763,6 +763,36 @@ describe('auctionmanager.js', function () {
         assert.equal(addedBid.renderer.url, 'renderer.js');
       });
 
+      it('installs publisher-defined renderers for a media type', function () {
+        const renderer = {
+          url: 'videoRenderer.js',
+          render: (bid) => bid
+        };
+        let myBid = mockBid();
+        let bidRequest = mockBidRequest(myBid);
+
+        bidRequest.bids[0] = {
+          ...bidRequest.bids[0],
+          mediaTypes: {
+            banner: {
+              sizes: [[300, 250], [300, 600]]
+            },
+            video: {
+              context: 'outstream',
+              renderer
+            }
+          }
+        };
+        makeRequestsStub.returns([bidRequest]);
+
+        myBid.mediaType = 'video';
+        spec.interpretResponse.returns(myBid);
+        auction.callBids();
+
+        const addedBid = auction.getBidsReceived().pop();
+        assert.equal(addedBid.renderer.url, renderer.url);
+      });
+
       it('bid for a regular unit and a video unit', function() {
         let renderer = {
           url: 'renderer.js',

test/spec/video_spec.js

@@ -71,6 +71,29 @@ describe('video.js', function () {
     expect(valid).to.equal(true);
   });
 
+  it('validates valid outstream bids with a publisher defined renderer', function () {
+    const bid = {
+      requestId: '123abc',
+    };
+    const bidRequests = [{
+      bids: [{
+        bidId: '123abc',
+        bidder: 'appnexus',
+        mediaTypes: {
+          video: {
+            context: 'outstream',
+            renderer: {
+              url: 'render.url',
+              render: () => true,
+            }
+          }
+        }
+      }]
+    }];
+    const valid = isValidVideoBid(bid, bidRequests);
+    expect(valid).to.equal(true);
+  });
+
   it('catches invalid outstream bids', function () {
     const bid = {
       requestId: '123abc'