From 1c529e9d186e6e0b169ca224d506146577c75651 Mon Sep 17 00:00:00 2001
From: Kev <fisherk.work@gmail.com>
Date: Thu, 29 May 2025 12:44:53 -0400
Subject: [PATCH] feat(ourlogs): Add replay id to logs when available

Logs can't lookup replays via traces since traces may be sampled whereas logs are (currently) unsampled, with their own traceids.
---
 packages/core/src/logs/exports.ts           |  8 ++++
 packages/core/test/lib/logs/exports.test.ts | 45 +++++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/packages/core/src/logs/exports.ts b/packages/core/src/logs/exports.ts
index 9a738d503a80..6a356af53678 100644
--- a/packages/core/src/logs/exports.ts
+++ b/packages/core/src/logs/exports.ts
@@ -10,6 +10,7 @@ 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';
+import { Integration } from '../types-hoist/integration';
 
 const MAX_LOG_BUFFER_SIZE = 100;
 
@@ -111,6 +112,9 @@ export function _INTERNAL_captureLog(
     return;
   }
 
+
+  const replay = client.getIntegrationByName<Integration & { getReplayId: () => string }>('Replay');
+  const replayId = replay?.getReplayId();
   const [, traceContext] = _getTraceInfoFromScope(client, scope);
 
   const processedLogAttributes = {
@@ -125,6 +129,10 @@ export function _INTERNAL_captureLog(
     processedLogAttributes['sentry.environment'] = environment;
   }
 
+  if (replayId) {
+    processedLogAttributes['sentry.replay_id'] = replayId;
+  }
+
   const { sdk } = client.getSdkMetadata() ?? {};
   if (sdk) {
     processedLogAttributes['sentry.sdk.name'] = sdk.name;
diff --git a/packages/core/test/lib/logs/exports.test.ts b/packages/core/test/lib/logs/exports.test.ts
index 1ae570bc5968..798804e9841a 100644
--- a/packages/core/test/lib/logs/exports.test.ts
+++ b/packages/core/test/lib/logs/exports.test.ts
@@ -9,6 +9,7 @@ import {
 import type { Log } from '../../../src/types-hoist/log';
 import * as loggerModule from '../../../src/utils-hoist/logger';
 import { getDefaultTestClientOptions, TestClient } from '../../mocks/client';
+import { Replay } from '../../../../replay-internal/src/integration';
 
 const PUBLIC_DSN = 'https://username@domain/123';
 
@@ -155,6 +156,50 @@ describe('_INTERNAL_captureLog', () => {
     });
   });
 
+  it('includes replay id in log attributes when available', async () => {
+
+    let _initialized = false;
+    class TestReplayIntegration extends Replay {
+      protected get _isInitialized(): boolean {
+        return _initialized;
+      }
+      protected set _isInitialized(value: boolean) {
+        _initialized = value;
+      }
+
+      public afterAllSetup(): void {
+        // do nothing, we need to manually initialize this
+      }
+    }
+    const replayIntegration = new TestReplayIntegration();
+    const options = getDefaultTestClientOptions({
+      dsn: PUBLIC_DSN,
+      _experiments: { enableLogs: true },
+      integrations: [replayIntegration],
+    });
+
+    const client = new TestClient(options);
+
+    replayIntegration['_setup'](client as any);
+    replayIntegration['_initialize'](client as any);
+
+    const scope = new Scope();
+    scope.setPropagationContext({
+      traceId: '3d9355f71e9c444b81161599adac6e29',
+      sampleRand: 1,
+    });
+
+    _INTERNAL_captureLog({ level: 'info', message: 'test log with replay id' }, client, scope);
+
+    const logAttributes = _INTERNAL_getLogBuffer(client)?.[0]?.attributes;
+    expect(logAttributes).toEqual({
+      'sentry.replay_id': {
+        value: '123',
+        type: 'string',
+      },
+    });
+  });
+
   it('includes SDK metadata in log attributes when available', () => {
     const options = getDefaultTestClientOptions({
       dsn: PUBLIC_DSN,