fix(logs): Ensure logs can be flushed correctly

Stores the Client to LogBuffer WeakMap onto the global object so logs can be
retrieved correctly during flushing. Previously, the WeakMap reference would be
different at flush time, causing no logs to be found for any given client.

Adds an express e2e tests to ensure logs are flushed correctly.

Author: andreiborza

dev-packages/e2e-tests/test-applications/node-express/src/app.ts

@@ -13,6 +13,9 @@ Sentry.init({
   debug: !!process.env.DEBUG,
   tunnel: `http://localhost:3031/`, // proxy server
   tracesSampleRate: 1,
+  _experiments: {
+    enableLogs: true,
+  },
 });
 
 import { TRPCError, initTRPC } from '@trpc/server';
@@ -30,6 +33,11 @@ app.get('/test-success', function (req, res) {
   res.send({ version: 'v1' });
 });
 
+app.get('/test-log', function (req, res) {
+  Sentry.logger.debug('Accessed /test-log route');
+  res.send({ message: 'Log sent' });
+});
+
 app.get('/test-param/:param', function (req, res) {
   res.send({ paramWas: req.params.param });
 });

dev-packages/e2e-tests/test-applications/node-express/tests/logs.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+import { waitForEnvelopeItem } from '@sentry-internal/test-utils';
+import type { SerializedLog, SerializedLogContainer } from '@sentry/core';
+
+test('should send logs', async ({ baseURL }) => {
+  const logEnvelopePromise = waitForEnvelopeItem('node-express', envelope => {
+    return envelope[0].type === 'log' && (envelope[1] as SerializedLogContainer).items[0]?.level === 'debug';
+  });
+
+  await fetch(`${baseURL}/test-log`);
+
+  const logEnvelope = await logEnvelopePromise;
+  const log = (logEnvelope[1] as SerializedLogContainer).items[0];
+  expect(log?.level).toBe('debug');
+  expect(log?.body).toBe('Accessed /test-log route');
+});

packages/core/src/logs/exports.ts

@@ -7,12 +7,14 @@ import { _getSpanForScope } from '../utils/spanOnScope';
 import { isParameterizedString } from '../utils-hoist/is';
 import { logger } from '../utils-hoist/logger';
 import { timestampInSeconds } from '../utils-hoist/time';
+import { GLOBAL_OBJ } from '../utils-hoist/worldwide';
 import { SEVERITY_TEXT_TO_SEVERITY_NUMBER } from './constants';
 import { createLogEnvelope } from './envelope';
 
 const MAX_LOG_BUFFER_SIZE = 100;
 
-const CLIENT_TO_LOG_BUFFER_MAP = new WeakMap<Client, Array<SerializedLog>>();
+// The reference to the Client <> LogBuffer map is stored to ensure it's always the same
+GLOBAL_OBJ._sentryClientToLogBufferMap = new WeakMap<Client, Array<SerializedLog>>();
 
 /**
  * Converts a log attribute to a serialized log attribute.
@@ -149,11 +151,11 @@ export function _INTERNAL_captureLog(
     ),
   };
 
-  const logBuffer = CLIENT_TO_LOG_BUFFER_MAP.get(client);
+  const logBuffer = _INTERNAL_getLogBuffer(client);
   if (logBuffer === undefined) {
-    CLIENT_TO_LOG_BUFFER_MAP.set(client, [serializedLog]);
+    GLOBAL_OBJ._sentryClientToLogBufferMap?.set(client, [serializedLog]);
   } else {
-    CLIENT_TO_LOG_BUFFER_MAP.set(client, [...logBuffer, serializedLog]);
+    GLOBAL_OBJ._sentryClientToLogBufferMap?.set(client, [...logBuffer, serializedLog]);
     if (logBuffer.length >= MAX_LOG_BUFFER_SIZE) {
       _INTERNAL_flushLogsBuffer(client, logBuffer);
     }
@@ -181,7 +183,7 @@ export function _INTERNAL_flushLogsBuffer(client: Client, maybeLogBuffer?: Array
   const envelope = createLogEnvelope(logBuffer, clientOptions._metadata, clientOptions.tunnel, client.getDsn());
 
   // Clear the log buffer after envelopes have been constructed.
-  CLIENT_TO_LOG_BUFFER_MAP.set(client, []);
+  GLOBAL_OBJ._sentryClientToLogBufferMap?.set(client, []);
 
   client.emit('flushLogs');
 
@@ -199,5 +201,5 @@ export function _INTERNAL_flushLogsBuffer(client: Client, maybeLogBuffer?: Array
  * @returns The log buffer for the given client.
  */
 export function _INTERNAL_getLogBuffer(client: Client): Array<SerializedLog> | undefined {
-  return CLIENT_TO_LOG_BUFFER_MAP.get(client);
+  return GLOBAL_OBJ._sentryClientToLogBufferMap?.get(client);
 }

packages/core/src/utils-hoist/worldwide.ts

@@ -13,6 +13,8 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
 import type { Carrier } from '../carrier';
+import type { Client } from '../client';
+import type { SerializedLog } from '../types-hoist/log';
 import type { SdkSource } from './env';
 
 /** Internal global with common properties and Sentry extensions  */
@@ -35,6 +37,12 @@ export type InternalGlobal = {
     id?: string;
   };
   SENTRY_SDK_SOURCE?: SdkSource;
+  /**
+   * A map of Sentry clients to their log buffers.
+   *
+   * This is used to store logs that are sent to Sentry.
+   */
+  _sentryClientToLogBufferMap?: WeakMap<Client, Array<SerializedLog>>;
   /**
    * Debug IDs are indirectly injected by Sentry CLI or bundler plugins to directly reference a particular source map
    * for resolving of a source file. The injected code will place an entry into the record for each loaded bundle/JS