cleanup helper

Author: ChristianPavilonis

crates/common/src/auction/formats.rs

@@ -16,9 +16,7 @@ use crate::auction::context::ContextValue;
 use crate::creative;
 use crate::error::TrustedServerError;
 use crate::geo::GeoInfo;
-use crate::openrtb::{
-    maybe_object_from_serializable, OpenRtbBid, OpenRtbResponse, ResponseExt, SeatBid,
-};
+use crate::openrtb::{OpenRtbBid, OpenRtbResponse, ResponseExt, SeatBid, ToExt};
 use crate::settings::Settings;
 use crate::synthetic::{generate_synthetic_id, get_or_generate_synthetic_id};
 
@@ -278,15 +276,16 @@ pub fn convert_to_openrtb_response(
     let response_body = OpenRtbResponse {
         id: auction_request.id.to_string(),
         seatbid: Some(seatbids),
-        ext: maybe_object_from_serializable(&ResponseExt {
+        ext: ResponseExt {
             orchestrator: OrchestratorExt {
                 strategy: strategy_name.to_string(),
                 providers: result.provider_responses.len(),
                 total_bids: result.total_bids(),
                 time_ms: result.total_time_ms,
                 provider_details,
             },
-        }),
+        }
+        .to_ext(),
         ..Default::default()
     };
 

crates/common/src/integrations/prebid.rs

@@ -23,8 +23,8 @@ use crate::integrations::{
     IntegrationRegistration,
 };
 use crate::openrtb::{
-    maybe_object_from_serializable, Banner, Device, Format, Geo, Imp, ImpExt, OpenRtbRequest,
-    PrebidExt, PrebidImpExt, Publisher, Regs, RequestExt, Site, TrustedServerExt, User, UserExt,
+    Banner, Device, Format, Geo, Imp, ImpExt, OpenRtbRequest, PrebidExt, PrebidImpExt, Publisher,
+    Regs, RequestExt, Site, ToExt, TrustedServerExt, User, UserExt,
 };
 use crate::request_signing::{RequestSigner, SigningParams, SIGNING_VERSION};
 use crate::settings::{IntegrationConfig, Settings};
@@ -605,9 +605,10 @@ impl PrebidAuctionProvider {
                     bidfloorcur: slot.floor_price.map(|_| "USD".to_string()),
                     secure: Some(1), // require HTTPS creatives
                     tagid: Some(slot.id.clone()),
-                    ext: maybe_object_from_serializable(&ImpExt {
+                    ext: ImpExt {
                         prebid: PrebidImpExt { bidder },
-                    }),
+                    }
+                    .to_ext(),
                     ..Default::default()
                 }
             })
@@ -626,9 +627,10 @@ impl PrebidAuctionProvider {
         let user = Some(User {
             id: Some(request.user.id.clone()),
             consent: request.user.consent.clone(),
-            ext: maybe_object_from_serializable(&UserExt {
+            ext: UserExt {
                 synthetic_fresh: Some(request.user.fresh_id.clone()),
-            }),
+            }
+            .to_ext(),
             ..Default::default()
         });
 
@@ -725,7 +727,7 @@ impl PrebidAuctionProvider {
 
         let debug_enabled = self.config.debug;
 
-        let ext = maybe_object_from_serializable(&RequestExt {
+        let ext = RequestExt {
             prebid: Some(PrebidExt {
                 debug: debug_enabled.then_some(true),
                 returnallbidstatus: debug_enabled.then_some(true),
@@ -738,7 +740,8 @@ impl PrebidAuctionProvider {
                 request_scheme: Some(request_info.scheme),
                 ts,
             }),
-        });
+        }
+        .to_ext();
 
         // Extract Referer header for site.ref
         let referer = context

crates/common/src/openrtb.rs

@@ -1,33 +1,16 @@
 use serde::Serialize;
-use serde_json::{Map, Value};
+use serde_json::Value;
 
 use crate::auction::types::OrchestratorExt;
 
-pub type Object = trusted_server_openrtb::Object;
 pub type OpenRtbRequest = trusted_server_openrtb::BidRequest;
 pub type OpenRtbResponse = trusted_server_openrtb::BidResponse;
 pub type OpenRtbBid = trusted_server_openrtb::Bid;
 
 pub use trusted_server_openrtb::{
-    Banner, Bid, BidResponse, Device, Format, Geo, Imp, Publisher, Regs, SeatBid, Site, User,
+    Banner, Bid, BidResponse, Device, Format, Geo, Imp, Publisher, Regs, SeatBid, Site, ToExt, User,
 };
 
-pub fn object_from_serializable<T: Serialize>(value: &T) -> Object {
-    match serde_json::to_value(value) {
-        Ok(Value::Object(map)) => map,
-        Ok(_) | Err(_) => Map::new(),
-    }
-}
-
-pub fn maybe_object_from_serializable<T: Serialize>(value: &T) -> Option<Object> {
-    let map = object_from_serializable(value);
-    if map.is_empty() {
-        None
-    } else {
-        Some(map)
-    }
-}
-
 // ============================================================================
 // Extension types (project-specific, not part of the OpenRTB spec)
 // ============================================================================
@@ -112,15 +95,16 @@ mod tests {
             ..Default::default()
         };
 
-        let ext = maybe_object_from_serializable(&ResponseExt {
+        let ext = ResponseExt {
             orchestrator: OrchestratorExt {
                 strategy: "parallel_only".to_string(),
                 providers: 2,
                 total_bids: 3,
                 time_ms: 12,
                 provider_details: vec![],
             },
-        });
+        }
+        .to_ext();
 
         let response = OpenRtbResponse {
             id: "auction-1".to_string(),

crates/openrtb/src/lib.rs

@@ -5,6 +5,23 @@ use serde_json::{Map, Value};
 
 pub type Object = Map<String, Value>;
 
+/// Convert a serializable struct into an `Option<Object>` suitable for an
+/// `OpenRTB` `ext` field. Returns `None` when serialization produces an empty
+/// map (i.e. all fields were skipped), so that `ext` is omitted from the JSON
+/// output rather than emitting `"ext": {}`.
+pub trait ToExt {
+    fn to_ext(&self) -> Option<Object>;
+}
+
+impl<T: Serialize> ToExt for T {
+    fn to_ext(&self) -> Option<Object> {
+        match serde_json::to_value(self) {
+            Ok(Value::Object(map)) if !map.is_empty() => Some(map),
+            _ => None,
+        }
+    }
+}
+
 #[derive(Debug, Clone, Default, Serialize, Deserialize)]
 pub struct BidRequest {
     pub id: String,