feat(core): Add new transports to base backend

Adds new transports to base backend in core. For now, they are gated
behind `options._experiments.newTransport = true`.

The next step is to add new transports for fetch, xhr (browser) as well
as http, https (node).

Author: AbhiPrasad

packages/core/src/basebackend.ts

@@ -1,6 +1,9 @@
 import { Event, EventHint, Options, Session, Severity, Transport } from '@sentry/types';
 import { isDebugBuild, logger, SentryError } from '@sentry/utils';
 
+import { initAPIDetails } from './api';
+import { createEventEnvelope, createSessionEnvelope } from './request';
+import { NewTransport } from './transports/base';
 import { NoopTransport } from './transports/noop';
 
 /**
@@ -63,6 +66,9 @@ export abstract class BaseBackend<O extends Options> implements Backend {
   /** Cached transport used internally. */
   protected _transport: Transport;
 
+  /** New v7 Transport that is initialized alongside the old one */
+  protected _newTransport?: NewTransport;
+
   /** Creates a new backend instance. */
   public constructor(options: O) {
     this._options = options;
@@ -91,9 +97,23 @@ export abstract class BaseBackend<O extends Options> implements Backend {
    * @inheritDoc
    */
   public sendEvent(event: Event): void {
-    void this._transport.sendEvent(event).then(null, reason => {
-      isDebugBuild() && logger.error('Error while sending event:', reason);
-    });
+    // TODO(v7): Remove the if-else
+    if (
+      this._newTransport &&
+      this._options.dsn &&
+      this._options._experiments &&
+      this._options._experiments.newTransport
+    ) {
+      const api = initAPIDetails(this._options.dsn, this._options._metadata, this._options.tunnel);
+      const env = createEventEnvelope(event, api);
+      void this._newTransport.send(env).then(null, reason => {
+        isDebugBuild() && logger.error('Error while sending event:', reason);
+      });
+    } else {
+      void this._transport.sendEvent(event).then(null, reason => {
+        isDebugBuild() && logger.error('Error while sending event:', reason);
+      });
+    }
   }
 
   /**
@@ -105,9 +125,23 @@ export abstract class BaseBackend<O extends Options> implements Backend {
       return;
     }
 
-    void this._transport.sendSession(session).then(null, reason => {
-      isDebugBuild() && logger.error('Error while sending session:', reason);
-    });
+    // TODO(v7): Remove the if-else
+    if (
+      this._newTransport &&
+      this._options.dsn &&
+      this._options._experiments &&
+      this._options._experiments.newTransport
+    ) {
+      const api = initAPIDetails(this._options.dsn, this._options._metadata, this._options.tunnel);
+      const [env] = createSessionEnvelope(session, api);
+      void this._newTransport.send(env).then(null, reason => {
+        isDebugBuild() && logger.error('Error while sending session:', reason);
+      });
+    } else {
+      void this._transport.sendSession(session).then(null, reason => {
+        isDebugBuild() && logger.error('Error while sending session:', reason);
+      });
+    }
   }
 
   /**
@@ -123,4 +157,6 @@ export abstract class BaseBackend<O extends Options> implements Backend {
   protected _setupTransport(): Transport {
     return new NoopTransport();
   }
+
+  protected abstract _setupNewTransport(): NewTransport;
 }

packages/core/src/request.ts

@@ -39,8 +39,11 @@ function enhanceEventWithSdkInfo(event: Event, sdkInfo?: SdkInfo): Event {
   return event;
 }
 
-/** Creates a SentryRequest from a Session. */
-export function sessionToSentryRequest(session: Session | SessionAggregates, api: APIDetails): SentryRequest {
+/** Creates an envelope from a Session */
+export function createSessionEnvelope(
+  session: Session | SessionAggregates,
+  api: APIDetails,
+): [SessionEnvelope, SentryRequestType] {
   const sdkInfo = getSdkMetadataForEnvelopeHeader(api);
   const envelopeHeaders = {
     sent_at: new Date().toISOString(),
@@ -54,13 +57,47 @@ export function sessionToSentryRequest(session: Session | SessionAggregates, api
   // TODO (v7) Have to cast type because envelope items do not accept a `SentryRequestType`
   const envelopeItem = [{ type } as { type: 'session' | 'sessions' }, session] as SessionItem;
   const envelope = createEnvelope<SessionEnvelope>(envelopeHeaders, [envelopeItem]);
+
+  return [envelope, type];
+}
+
+/** Creates a SentryRequest from a Session. */
+export function sessionToSentryRequest(session: Session | SessionAggregates, api: APIDetails): SentryRequest {
+  const [envelope, type] = createSessionEnvelope(session, api);
   return {
     body: serializeEnvelope(envelope),
     type,
     url: getEnvelopeEndpointWithUrlEncodedAuth(api.dsn, api.tunnel),
   };
 }
 
+/**
+ * Create an Envelope from an event. Note that this is duplicated from below,
+ * but on purpose as this will be refactored in v7.
+ */
+export function createEventEnvelope(event: Event, api: APIDetails): EventEnvelope {
+  const sdkInfo = getSdkMetadataForEnvelopeHeader(api);
+  const eventType = event.type || 'event';
+
+  const { transactionSampling } = event.sdkProcessingMetadata || {};
+  const { method: samplingMethod, rate: sampleRate } = transactionSampling || {};
+
+  const envelopeHeaders = {
+    event_id: event.event_id as string,
+    sent_at: new Date().toISOString(),
+    ...(sdkInfo && { sdk: sdkInfo }),
+    ...(!!api.tunnel && { dsn: dsnToString(api.dsn) }),
+  };
+  const eventItem: EventItem = [
+    {
+      type: eventType,
+      sample_rates: [{ id: samplingMethod, rate: sampleRate }],
+    },
+    event,
+  ];
+  return createEnvelope<EventEnvelope>(envelopeHeaders, [eventItem]);
+}
+
 /** Creates a SentryRequest from an event. */
 export function eventToSentryRequest(event: Event, api: APIDetails): SentryRequest {
   const sdkInfo = getSdkMetadataForEnvelopeHeader(api);

packages/core/src/transports/base.ts

@@ -79,10 +79,6 @@ export interface NodeTransportOptions extends BaseTransportOptions {
 }
 
 export interface NewTransport {
-  // If `$` is set, we know that this is a new transport.
-  // TODO(v7): Remove this as we will no longer have split between
-  // old and new transports.
-  $: boolean;
   send(request: Envelope): PromiseLike<TransportResponse>;
   flush(timeout?: number): PromiseLike<boolean>;
 }
@@ -143,7 +139,6 @@ export function createTransport(
   }
 
   return {
-    $: true,
     send,
     flush,
   };

packages/core/test/lib/transports/base.test.ts

@@ -20,11 +20,6 @@ const TRANSACTION_ENVELOPE = createEnvelope<EventEnvelope>(
 );
 
 describe('createTransport', () => {
-  it('has $ property', () => {
-    const transport = createTransport({}, _ => resolvedSyncPromise({ statusCode: 200 }));
-    expect(transport.$).toBeDefined();
-  });
-
   it('flushes the buffer', async () => {
     const mockBuffer: PromiseBuffer<TransportResponse> = {
       $: [],