feat(core): Send baggage in envelope header

WIP, currently a very simple and unsustainable solution that doesn't take immutability or additional data
into account

Author: Lms24

packages/core/src/baseclient.ts

@@ -618,7 +618,7 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
           throw new SentryError('`beforeSend` returned `null`, will not send event.');
         }
 
-        const session = scope && scope.getSession && scope.getSession();
+        const session = scope && scope.getSession();
         if (!isTransaction && session) {
           this._updateSessionFromEvent(session, processedEvent);
         }

packages/core/src/envelope.ts

@@ -10,7 +10,7 @@ import {
   SessionEnvelope,
   SessionItem,
 } from '@sentry/types';
-import { createEnvelope, dsnToString } from '@sentry/utils';
+import { createBaggage, createEnvelope, dsnToString, serializeBaggage } from '@sentry/utils';
 
 /** Extract sdk info from from the API metadata */
 function getSdkMetadataForEnvelopeHeader(metadata?: SdkMetadata): SdkInfo | undefined {
@@ -101,9 +101,12 @@ export function createEventEnvelope(
   // TODO: This is NOT part of the hack - DO NOT DELETE
   delete event.sdkProcessingMetadata;
 
+  const baggage = createBaggage({ environment: event.environment, release: event.release });
+
   const envelopeHeaders = {
     event_id: event.event_id as string,
     sent_at: new Date().toISOString(),
+    baggage: serializeBaggage(baggage),
     ...(sdkInfo && { sdk: sdkInfo }),
     ...(!!tunnel && { dsn: dsnToString(dsn) }),
   };

packages/types/src/envelope.ts

@@ -56,7 +56,7 @@ export type SessionItem =
   | BaseEnvelopeItem<SessionAggregatesItemHeaders, SessionAggregates>;
 export type ClientReportItem = BaseEnvelopeItem<ClientReportItemHeaders, ClientReport>;
 
-type EventEnvelopeHeaders = { event_id: string; sent_at: string };
+type EventEnvelopeHeaders = { event_id: string; sent_at: string; baggage?: string };
 type SessionEnvelopeHeaders = { sent_at: string };
 type ClientReportEnvelopeHeaders = BaseEnvelopeHeaders;
 

packages/utils/src/index.ts

@@ -23,3 +23,4 @@ export * from './env';
 export * from './envelope';
 export * from './clientreport';
 export * from './ratelimit';
+export * from './baggage';