add beforeSendTransaction option

Author: lobsterkatie

packages/core/src/baseclient.ts

@@ -613,13 +613,17 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
    * @returns A SyncPromise that resolves with the event or rejects in case event was/will not be send.
    */
   protected _processEvent(event: Event, hint: EventHint, scope?: Scope): PromiseLike<Event> {
-    const { beforeSend, sampleRate } = this.getOptions();
+    const options = this.getOptions();
+    const { sampleRate } = options;
 
     if (!this._isEnabled()) {
       return rejectedSyncPromise(new SentryError('SDK not enabled, will not capture event.', 'log'));
     }
 
     const isTransaction = event.type === 'transaction';
+    const beforeSendProcessorName = isTransaction ? 'beforeSendTransaction' : 'beforeSend';
+    const beforeSendProcessor = options[beforeSendProcessorName];
+
     // 1.0 === 100% events are sent
     // 0.0 === 0% events are sent
     // Sampling for transaction happens somewhere else
@@ -641,17 +645,17 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
         }
 
         const isInternalException = hint.data && (hint.data as { __sentry__: boolean }).__sentry__ === true;
-        if (isInternalException || isTransaction || !beforeSend) {
+        if (isInternalException || !beforeSendProcessor) {
           return prepared;
         }
 
-        const beforeSendResult = beforeSend(prepared, hint);
-        return _ensureBeforeSendRv(beforeSendResult);
+        const beforeSendResult = beforeSendProcessor(prepared, hint);
+        return _ensureBeforeSendRv(beforeSendResult, beforeSendProcessorName);
       })
       .then(processedEvent => {
         if (processedEvent === null) {
           this.recordDroppedEvent('before_send', event.type || 'error');
-          throw new SentryError('`beforeSend` returned `null`, will not send event.', 'log');
+          throw new SentryError(`\`${beforeSendProcessorName}\` returned \`null\`, will not send event.`, 'log');
         }
 
         const session = scope && scope.getSession();
@@ -764,10 +768,13 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
 }
 
 /**
- * Verifies that return value of configured `beforeSend` is of expected type.
+ * Verifies that return value of configured `beforeSend` or `beforeSendTransaction` is of expected type.
  */
-function _ensureBeforeSendRv(rv: PromiseLike<Event | null> | Event | null): PromiseLike<Event | null> | Event | null {
-  const nullErr = '`beforeSend` method has to return `null` or a valid event.';
+function _ensureBeforeSendRv(
+  rv: PromiseLike<Event | null> | Event | null,
+  beforeSendProcessorName: string,
+): PromiseLike<Event | null> | Event | null {
+  const nullErr = `\`${beforeSendProcessorName}\` must return \`null\` or a valid event.`;
   if (isThenable(rv)) {
     return rv.then(
       event => {
@@ -777,7 +784,7 @@ function _ensureBeforeSendRv(rv: PromiseLike<Event | null> | Event | null): Prom
         return event;
       },
       e => {
-        throw new SentryError(`beforeSend rejected with ${e}`);
+        throw new SentryError(`${beforeSendProcessorName} rejected with ${e}`);
       },
     );
   } else if (!(isPlainObject(rv) || rv === null)) {

packages/types/src/options.ts

@@ -195,19 +195,31 @@ export interface ClientOptions<TO extends BaseTransportOptions = BaseTransportOp
   tracesSampler?: (samplingContext: SamplingContext) => number | boolean;
 
   /**
-   * A callback invoked during event submission, allowing to optionally modify
-   * the event before it is sent to Sentry.
+   * An event-processing callback for error and message events, guaranteed to be invoked after all other event
+   * processors, which allows an event to be modified or dropped.
    *
-   * Note that you must return a valid event from this callback. If you do not
-   * wish to modify the event, simply return it at the end.
-   * Returning null will cause the event to be dropped.
+   * Note that you must return a valid event from this callback. If you do not wish to modify the event, simply return
+   * it at the end. Returning `null` will cause the event to be dropped.
    *
    * @param event The error or message event generated by the SDK.
-   * @param hint May contain additional information about the original exception.
+   * @param hint Event metadata useful for processing.
    * @returns A new event that will be sent | null.
    */
   beforeSend?: (event: Event, hint: EventHint) => PromiseLike<Event | null> | Event | null;
 
+  /**
+   * An event-processing callback for error and message events, guaranteed to be invoked after all other event
+   * processors, which allows an event to be modified or dropped.
+   *
+   * Note that you must return a valid event from this callback. If you do not wish to modify the event, simply return
+   * it at the end. Returning `null` will cause the event to be dropped.
+   *
+   * @param event The error or message event generated by the SDK.
+   * @param hint Event metadata useful for processing.
+   * @returns A new event that will be sent | null.
+   */
+  beforeSendTransaction?: (event: Event, hint: EventHint) => PromiseLike<Event | null> | Event | null;
+
   /**
    * A callback invoked when adding a breadcrumb, allowing to optionally modify
    * it before adding it to future events.