Mismatched type for Prebid Server

Type of issue

Bug / question

Description

Configuration for Rubicon is correct as client-side request (well, it's working), but once prebidServer is enabled - I'm getting errors on parameter types. Suspecting something is wrong with type conversion. Plus, debug / error message is unhelpful :(

Steps to reproduce

Configuration (sample):

pbjs.setConfig({
    bidderTimeout: PREBID_TIMEOUT,
    enableSendAllBids: true,
    s2sConfig: {
        accountId: 'e7445f8d-ee19-4a94-a234-a271cb3e6bc0',
        enabled: true,
        bidders: ['facebook', 'pulsepoint', 'rubicon'],
        timeout: PREBID_TIMEOUT
    } 
});

pbjs.addAdUnits([{
    code: "div-gpt-ad-1418309082456-0",
    sizes: [
        [728, 90],
        [970, 250]
    ],
    bids: [{
        bidder: "rubicon",
        params: {
            accountId: "14346",
            siteId: "154972",
            zoneId: "738672",
            sizes: "[2,57]"
        }
    }]
}]);

Result with ?pbjs_debug=true - no call is made:

MESSAGE: CALLING S2S HEADER BIDDERS ==== facebook,pulsepoint,rubicon
MESSAGE: Mismatched type for Prebid Server : rubicon : accountId. Required Type:function () { [native code] }
MESSAGE: Mismatched type for Prebid Server : rubicon : siteId. Required Type:function () { [native code] }
MESSAGE: Mismatched type for Prebid Server : rubicon : zoneId. Required Type:function () { [native code] }

Test page

Expected results

Rubicon bidding is done in server side.

Actual results

Rubicon adapter rejects bid as invalid - parameters are mismatched - therefore bid is not called.

Platform details

prebid.js build 0.32.0 +Rubicon adapter +PrebidServer adapter

Other information

https://github.com/prebid/prebid-server/issues/182#issuecomment-341414895

prebid / Prebid.js