fledge/tentative/resources/decision-logic.sub.py

# General decision logic script. Depending on query parameters, it can
# simulate a variety of network errors, and its scoreAd() and
# reportResult() functions can have arbitrary Javascript code injected
# in them. scoreAd() will by default return a desirability score of
# twice the bid for each ad, as long as the ad URL ends with the uuid.
def main(request, response):
    error = request.GET.first(b"error", None)

    if error == b"close-connection":
        # Close connection without writing anything, to simulate a network
        # error. The write call is needed to avoid writing the default headers.
        response.writer.write("")
        response.close_connection = True
        return

    if error == b"http-error":
        response.status = (404, b"OK")
    else:
        response.status = (200, b"OK")

    if error == b"wrong-content-type":
        response.headers.set(b"Content-Type", b"application/json")
    elif error != b"no-content-type":
        response.headers.set(b"Content-Type", b"application/javascript")

    if error == b"bad-allow-fledge":
        response.headers.set(b"Ad-Auction-Allowed", b"sometimes")
    elif error == b"fledge-not-allowed":
        response.headers.set(b"Ad-Auction-Allowed", b"false")
    elif error != b"no-allow-fledge":
        response.headers.set(b"Ad-Auction-Allowed", b"true")

    body = b''
    if error == b"no-body":
        return body
    if error != b"no-scoreAd":
        body += b"""
            // Comparison function checks if two arguments are the same.
            // Not intended for use on anything other than built-in types
            // (Arrays, objects, and primitive types).
            function deepEquals(a, b) {
              if (typeof a !== typeof b)
                return false;
              if (typeof a !== 'object' || a === null || b === null)
                return a === b;

              let aKeys = Object.keys(a);
              if (aKeys.length != Object.keys(b).length)
                return false;
              for (key in aKeys) {
                if (a.hasOwnProperty(key) != b.hasOwnProperty(key) ||
                    !deepEquals(a[key], b[key])) {
                  return false;
                }
              }
              return true;
            }

            function scoreAd(adMetadata, bid, auctionConfig, trustedScoringSignals,
                             browserSignals, directFromSellerSignals) {
              // Don't bid on interest group with the wrong uuid. This is to prevent
              // left over interest groups from other tests from affecting auction
              // results.
              if (!browserSignals.renderUrl.endsWith('uuid={{GET[uuid]}}') &&
                  !browserSignals.renderUrl.includes('uuid={{GET[uuid]}}&')) {
                return 0;
              }

              {{GET[scoreAd]}};
              return {desirability: 2 * bid, allowComponentAuction: true};
            }"""
    if error != b"no-reportResult":
        body += b"""
            function reportResult(auctionConfig, browserSignals, directFromSellerSignals) {
              {{GET[reportResult]}};
            }"""
    return body