fix: Remove keepalive from browser

Create only one instance of transport

Author: HazAT

packages/browser/src/backend.ts

@@ -1,5 +1,5 @@
 import { Backend, logger, Options, SentryError } from '@sentry/core';
-import { SentryEvent, SentryEventHint, SentryResponse, Severity, Status } from '@sentry/types';
+import { SentryEvent, SentryEventHint, SentryResponse, Severity, Status, Transport } from '@sentry/types';
 import { isDOMError, isDOMException, isError, isErrorEvent, isPlainObject } from '@sentry/utils/is';
 import { supportsFetch } from '@sentry/utils/supports';
 import { eventFromPlainObject, eventFromStacktrace, prepareFramesForEvent } from './parsers';
@@ -37,6 +37,9 @@ export class BrowserBackend implements Backend {
   /** Creates a new browser backend instance. */
   public constructor(private readonly options: BrowserOptions = {}) {}
 
+  /** Cached transport used internally. */
+  private transport?: Transport;
+
   /**
    * @inheritDoc
    */
@@ -142,15 +145,18 @@ export class BrowserBackend implements Backend {
       return { status: Status.Skipped };
     }
 
-    const transportOptions = this.options.transportOptions ? this.options.transportOptions : { dsn: this.options.dsn };
-
-    const transport = this.options.transport
-      ? new this.options.transport({ dsn: this.options.dsn })
-      : supportsFetch()
-        ? new FetchTransport(transportOptions)
-        : new XHRTransport(transportOptions);
+    if (!this.transport) {
+      const transportOptions = this.options.transportOptions
+        ? this.options.transportOptions
+        : { dsn: this.options.dsn };
+      this.transport = this.options.transport
+        ? new this.options.transport({ dsn: this.options.dsn })
+        : supportsFetch()
+          ? new FetchTransport(transportOptions)
+          : new XHRTransport(transportOptions);
+    }
 
-    return transport.send(event);
+    return this.transport.send(event);
   }
 
   /**

packages/browser/src/transports/fetch.ts

@@ -14,7 +14,6 @@ export class FetchTransport extends BaseTransport {
   public async send(event: SentryEvent): Promise<SentryResponse> {
     const defaultOptions: RequestInit = {
       body: serialize(event),
-      keepalive: true,
       method: 'POST',
       // Despite all stars in the sky saying that Edge supports old draft syntax, aka 'never', 'always', 'origin' and 'default
       // https://caniuse.com/#feat=referrer-policy

packages/node/src/backend.ts

@@ -1,6 +1,6 @@
 import { Backend, DSN, Options, SentryError } from '@sentry/core';
 import { getCurrentHub } from '@sentry/hub';
-import { SentryEvent, SentryEventHint, SentryResponse, Severity } from '@sentry/types';
+import { SentryEvent, SentryEventHint, SentryResponse, Severity, Transport } from '@sentry/types';
 import { isError, isPlainObject } from '@sentry/utils/is';
 import { limitObjectDepthToSize, serializeKeysToEventMessage } from '@sentry/utils/object';
 import * as md5 from 'md5';
@@ -24,6 +24,9 @@ export class NodeBackend implements Backend {
   /** Creates a new Node backend instance. */
   public constructor(private readonly options: NodeOptions = {}) {}
 
+  /** Cached transport used internally. */
+  private transport?: Transport;
+
   /**
    * @inheritDoc
    */
@@ -93,15 +96,16 @@ export class NodeBackend implements Backend {
       dsn = new DSN(this.options.dsn);
     }
 
-    const transportOptions = this.options.transportOptions ? this.options.transportOptions : { dsn };
-
-    const transport = this.options.transport
-      ? new this.options.transport({ dsn })
-      : dsn.protocol === 'http'
-        ? new HTTPTransport(transportOptions)
-        : new HTTPSTransport(transportOptions);
+    if (!this.transport) {
+      const transportOptions = this.options.transportOptions ? this.options.transportOptions : { dsn };
+      this.transport = this.options.transport
+        ? new this.options.transport({ dsn })
+        : dsn.protocol === 'http'
+          ? new HTTPTransport(transportOptions)
+          : new HTTPSTransport(transportOptions);
+    }
 
-    return transport.send(event);
+    return this.transport.send(event);
   }
 
   /**