overwrite transaction value after running addRequestDataToEvent

Author: lobsterkatie

packages/integrations/src/requestdata.ts

@@ -1,8 +1,12 @@
 // TODO (v8 or v9): Whenever this becomes a default integration for `@sentry/browser`, move this to `@sentry/core`. For
 // now, we leave it in `@sentry/integrations` so that it doesn't contribute bytes to our CDN bundles.
 
-import { EventProcessor, Hub, Integration } from '@sentry/types';
-import { addRequestDataToEvent as utilsAddRequestDataToEvent, AddRequestDataToEventOptions } from '@sentry/utils';
+import { EventProcessor, Hub, Integration, Transaction } from '@sentry/types';
+import {
+  addRequestDataToEvent as utilsAddRequestDataToEvent,
+  AddRequestDataToEventOptions,
+  extractPathForTransaction,
+} from '@sentry/utils';
 
 type RequestDataOptions = {
   /**
@@ -46,9 +50,14 @@ export class RequestData implements Integration {
    * @inheritDoc
    */
   public setupOnce(addGlobalEventProcessor: (eventProcessor: EventProcessor) => void, getCurrentHub: () => Hub): void {
-    const { include, _addReqDataCallback = utilsAddRequestDataToEvent } = this._options;
+    // Note: In the long run, most of the logic here should probably move into the request data utility functions. For
+    // the moment it lives here, though, until https://github.com/getsentry/sentry-javascript/issues/5718 is addressed.
+    // (TL;DR: Those functions touch many parts of the repo in many different ways, and need to be clened up. Once
+    // that's happened, it will be easier to add this logic in without worrying about unexpected side effects.)
 
     addGlobalEventProcessor(event => {
+      const { include = {}, _addReqDataCallback = utilsAddRequestDataToEvent } = this._options;
+
       const self = getCurrentHub().getIntegration(RequestData);
       const req = event.sdkProcessingMetadata && event.sdkProcessingMetadata.request;
 
@@ -58,7 +67,35 @@ export class RequestData implements Integration {
         return event;
       }
 
-      return _addReqDataCallback(event, req, { include });
+      const processedEvent = _addReqDataCallback(event, req, { include });
+
+      // In the cases where we either don't care about `transaction` value or already have the best data available, we're
+      // done
+      if (include.transaction === false || event.type === 'transaction' || include.transaction === 'handler') {
+        return processedEvent;
+      }
+
+      // In all other cases, use the request's associated transaction (if any) to overwrite the event's `transaction`
+      // value with a higher-quality one
+      const reqWithTransaction = req as { __sentry_transaction?: Transaction };
+      const transaction = reqWithTransaction.__sentry_transaction;
+      if (transaction) {
+        // TODO (v8): Remove the nextjs check and just always include the method for nextjs events. (Doing so is breaking
+        // because changing the names of transactions in Sentry has the potential to break things like alert rules.)
+        const shouldIncludeMethodInTransactionName =
+          event.sdk?.name === '@sentry/nextjs' ? transaction.name.startsWith('/api') : include.transaction !== 'path';
+
+        const [transactionValue] = extractPathForTransaction(req, {
+          path: true,
+          method: shouldIncludeMethodInTransactionName,
+          customRoute: transaction.name,
+        });
+        processedEvent.transaction = transactionValue;
+        // TODO: Find out if `source` is a thing it makes sense to add to error events
+        // processedEvent.transaction_info = { ...processedEvent.transaction_info, source };
+      }
+
+      return processedEvent;
     });
   }
 }