New Adapter: UNICORN

[faithnh]

Also fixed doc: prebid/prebid.github.io#2710

[SyntaxNode]

Thank you for reading the our new bidder docs.

[guscarreon]

Looks pretty good. A couple of comments before approving

[guscarreon]

Prebid server core passes a shallow copy of the openrtb.BidRequest object to the MakeRequest() function which makes pointer fields like Source to be red flags because they point to shared memory.

 14 type BidRequest struct {
 15
          .
          .
185
186     // Attribute:
187     //   source
188     // Type:
189     //   object
190     // Description:
191     //   A Sorce object (Section 3.2.2) that provides data about the
192     //   inventory source and which entity makes the final decision.
193     Source *Source `json:"source,omitempty"`
          .
          .
211 }
~/go/pkg/mod/github.com/mxm!cherry/[email protected]+incompatible/bid_request.go [RO]

Please create a new Source object copy locally and assign to the bidRequest. Notice that, depending on its initial configuration, prebid server core may or may not initialize bidRequest.Source field if it comes with a nil value (see endpoints/openrtb2/auction.go's line 311). In summary, we could do something like:

67     err := modifyImps(request, requestInfo)
68     if err != nil {
69         return nil, []error{err}
70     }
71
72 -   request.Source.Ext = setSourceExt()
   +   if request.Source != nil {
   +       modifiableSource = *request.Source
   +   } else {
   +       modifiableSource = &openrtb.Source{}
   +   }
   +   modifiableSource.Ext = setSourceExt()
   +   request.Source = modifiableSource
73
74     request.Ext, err = setExt(request)
75     if err != nil {
76         return nil, []error{err}
77     }
adapters/unicorn/unicorn.go

[faithnh]

Fixed it. Thank you so much!

c27da8b

[faithnh]

Fixed again because there is have copying source problem.

fb58a7e

[guscarreon]

The second parameter requestInfo *adapters.ExtraRequestInfo seems to not be used by this function at all. Do we need it?

[faithnh]

Certainly, requestInfo *adapters.ExtraRequestInfo is not used. Fixed it. Thank you!

c27da8b

[guscarreon]

@faithnh thank you for addressing the feedback. Your adapter looks pretty solid