ref(browser): Refactor sentry breadcrumb to use hook (#8892)

Noticed that this is a bit tightly coupled in the browser client, and
could be simplified by using a hook.

packages/browser/src/client.ts

@@ -15,8 +15,6 @@ import { createClientReportEnvelope, dsnToString, getSDKSource, logger } from '@
 
 import { eventFromException, eventFromMessage } from './eventbuilder';
 import { WINDOW } from './helpers';
-import type { Breadcrumbs } from './integrations';
-import { BREADCRUMB_INTEGRATION_ID } from './integrations/breadcrumbs';
 import type { BrowserTransportOptions } from './transports/types';
 import { createUserFeedbackEnvelope } from './userfeedback';
 
@@ -91,26 +89,6 @@ export class BrowserClient extends BaseClient<BrowserClientOptions> {
     return eventFromMessage(this._options.stackParser, message, level, hint, this._options.attachStacktrace);
   }
 
-  /**
-   * @inheritDoc
-   */
-  public sendEvent(event: Event, hint?: EventHint): void {
-    // We only want to add the sentry event breadcrumb when the user has the breadcrumb integration installed and
-    // activated its `sentry` option.
-    // We also do not want to use the `Breadcrumbs` class here directly, because we do not want it to be included in
-    // bundles, if it is not used by the SDK.
-    // This all sadly is a bit ugly, but we currently don't have a "pre-send" hook on the integrations so we do it this
-    // way for now.
-    const breadcrumbIntegration = this.getIntegrationById(BREADCRUMB_INTEGRATION_ID) as Breadcrumbs | undefined;
-    // We check for definedness of `addSentryBreadcrumb` in case users provided their own integration with id
-    // "Breadcrumbs" that does not have this function.
-    if (breadcrumbIntegration && breadcrumbIntegration.addSentryBreadcrumb) {
-      breadcrumbIntegration.addSentryBreadcrumb(event);
-    }
-
-    super.sendEvent(event, hint);
-  }
-
   /**
    * Sends user feedback to Sentry.
    */

packages/browser/src/integrations/breadcrumbs.ts

@@ -41,8 +41,6 @@ interface BreadcrumbsOptions {
 /** maxStringLength gets capped to prevent 100 breadcrumbs exceeding 1MB event payload size */
 const MAX_ALLOWED_STRING_LENGTH = 1024;
 
-export const BREADCRUMB_INTEGRATION_ID = 'Breadcrumbs';
-
 /**
  * Default Breadcrumbs instrumentations
  * TODO: Deprecated - with v6, this will be renamed to `Instrument`
@@ -51,7 +49,7 @@ export class Breadcrumbs implements Integration {
   /**
    * @inheritDoc
    */
-  public static id: string = BREADCRUMB_INTEGRATION_ID;
+  public static id: string = 'Breadcrumbs';
 
   /**
    * @inheritDoc
@@ -104,28 +102,30 @@ export class Breadcrumbs implements Integration {
     if (this.options.history) {
       addInstrumentationHandler('history', _historyBreadcrumb);
     }
-  }
-
-  /**
-   * Adds a breadcrumb for Sentry events or transactions if this option is enabled.
-   */
-  public addSentryBreadcrumb(event: SentryEvent): void {
     if (this.options.sentry) {
-      getCurrentHub().addBreadcrumb(
-        {
-          category: `sentry.${event.type === 'transaction' ? 'transaction' : 'event'}`,
-          event_id: event.event_id,
-          level: event.level,
-          message: getEventDescription(event),
-        },
-        {
-          event,
-        },
-      );
+      const client = getCurrentHub().getClient();
+      client && client.on && client.on('beforeSendEvent', addSentryBreadcrumb);
     }
   }
 }
 
+/**
+ * Adds a breadcrumb for Sentry events or transactions if this option is enabled.
+ */
+function addSentryBreadcrumb(event: SentryEvent): void {
+  getCurrentHub().addBreadcrumb(
+    {
+      category: `sentry.${event.type === 'transaction' ? 'transaction' : 'event'}`,
+      event_id: event.event_id,
+      level: event.level,
+      message: getEventDescription(event),
+    },
+    {
+      event,
+    },
+  );
+}
+
 /**
  * A HOC that creaes a function that creates breadcrumbs from DOM API calls.
  * This is a HOC so that we get access to dom options in the closure.

packages/core/src/baseclient.ts

@@ -322,6 +322,8 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
    * @inheritDoc
    */
   public sendEvent(event: Event, hint: EventHint = {}): void {
+    this.emit('beforeSendEvent', event, hint);
+
     if (this._dsn) {
       let env = createEventEnvelope(event, this._dsn, this._options._metadata, this._options.tunnel);
 
@@ -381,6 +383,9 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
   /** @inheritdoc */
   public on(hook: 'beforeEnvelope', callback: (envelope: Envelope) => void): void;
 
+  /** @inheritdoc */
+  public on(hook: 'beforeSendEvent', callback: (event: Event, hint?: EventHint) => void): void;
+
   /** @inheritdoc */
   public on(
     hook: 'afterSendEvent',
@@ -412,6 +417,9 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
   /** @inheritdoc */
   public emit(hook: 'beforeEnvelope', envelope: Envelope): void;
 
+  /** @inheritdoc */
+  public emit(hook: 'beforeSendEvent', event: Event, hint?: EventHint): void;
+
   /** @inheritdoc */
   public emit(hook: 'afterSendEvent', event: Event, sendResponse: TransportMakeRequestResponse | void): void;
 

packages/types/src/client.ts

@@ -176,6 +176,11 @@ export interface Client<O extends ClientOptions = ClientOptions> {
    */
   on?(hook: 'beforeEnvelope', callback: (envelope: Envelope) => void): void;
 
+  /**
+   * Register a callback for before an event is sent.
+   */
+  on?(hook: 'beforeSendEvent', callback: (event: Event, hint?: EventHint | void) => void): void;
+
   /**
    * Register a callback for when an event has been sent.
    */
@@ -212,6 +217,12 @@ export interface Client<O extends ClientOptions = ClientOptions> {
    */
   emit?(hook: 'beforeEnvelope', envelope: Envelope): void;
 
+  /*
+   * Fire a hook event before sending an event. Expects to be given an Event & EventHint as the
+   * second/third argument.
+   */
+  emit?(hook: 'beforeSendEvent', event: Event, hint?: EventHint): void;
+
   /*
    * Fire a hook event after sending an event. Expects to be given an Event as the
    * second argument.