fix(replays): Record sentry._internal.replay_is_buffering for spans

[mjq]

The currently replay ID is stored using the sentry.replay_id attribute. This attribute is set when the current replay's recording mode is either sampled (i.e. it will be sent to Sentry) or buffer (i.e. it may be sent to Sentry, if an error occurs). Because a buffered replay might not actually be sent to Sentry, logs and metrics set an additional sentry._internal.replay_is_buffering attribute so that the product knows it can't assume the replay actually exists:

sentry-javascript/packages/core/src/logs/internal.ts

Lines 122 to 128 in 3107899

	constreplayId=replay?.getReplayId(true);
	setLogAttribute(processedLogAttributes,'sentry.replay_id',replayId);
	if(replayId&&replay?.getRecordingMode()==='buffer'){
	// We send this so we can identify cases where the replayId is attached but the replay itself might not have been sent to Sentry
	setLogAttribute(processedLogAttributes,'sentry._internal.replay_is_buffering',true);
	}

sentry-javascript/packages/core/src/metrics/internal.ts

Lines 111 to 116 in 3107899

	constreplayId=replay?.getReplayId(true);
	setMetricAttribute(processedMetricAttributes,'sentry.replay_id',replayId);
	if(replayId&&replay?.getRecordingMode()==='buffer'){
	setMetricAttribute(processedMetricAttributes,'sentry._internal.replay_is_buffering',true);
	}

Spans, however, don't currently set this attribute. For consistency, set it on spans too.

---

🤖: Used Claude Code (Opus 4.6) to generate the code, with human refactoring + careful review.

[github-actions]

size-limit report 📦

Path	Size	% Change	Change
@sentry/browser	27.2 kB	-	-
@sentry/browser - with treeshaking flags	25.65 kB	-	-
@sentry/browser (incl. Tracing)	45.25 kB	-	-
@sentry/browser (incl. Tracing + Span Streaming)	47.48 kB	-	-
@sentry/browser (incl. Tracing, Profiling)	50.24 kB	-	-
@sentry/browser (incl. Tracing, Replay)	84.87 kB	+0.04%	+26 B 🔺
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	74.44 kB	+0.04%	+28 B 🔺
@sentry/browser (incl. Tracing, Replay with Canvas)	89.58 kB	+0.03%	+26 B 🔺
@sentry/browser (incl. Tracing, Replay, Feedback)	102.2 kB	+0.03%	+26 B 🔺
@sentry/browser (incl. Feedback)	44.36 kB	-	-
@sentry/browser (incl. sendFeedback)	32.02 kB	-	-
@sentry/browser (incl. FeedbackAsync)	37.11 kB	-	-
@sentry/browser (incl. Metrics)	28.27 kB	-	-
@sentry/browser (incl. Logs)	28.51 kB	-	-
@sentry/browser (incl. Metrics & Logs)	29.22 kB	-	-
@sentry/react	29.03 kB	-	-
@sentry/react (incl. Tracing)	47.53 kB	-	-
@sentry/vue	32.22 kB	-	-
@sentry/vue (incl. Tracing)	47.17 kB	-	-
@sentry/svelte	27.23 kB	-	-
CDN Bundle	29.57 kB	-	-
CDN Bundle (incl. Tracing)	47.82 kB	-	-
CDN Bundle (incl. Logs, Metrics)	31.08 kB	-	-
CDN Bundle (incl. Tracing, Logs, Metrics)	49.06 kB	-	-
CDN Bundle (incl. Replay, Logs, Metrics)	70.36 kB	+0.04%	+28 B 🔺
CDN Bundle (incl. Tracing, Replay)	85.22 kB	+0.04%	+26 B 🔺
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)	86.39 kB	+0.04%	+31 B 🔺
CDN Bundle (incl. Tracing, Replay, Feedback)	91.08 kB	+0.03%	+26 B 🔺
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)	92.23 kB	+0.03%	+25 B 🔺
CDN Bundle - uncompressed	87.7 kB	-	-
CDN Bundle (incl. Tracing) - uncompressed	144.13 kB	-	-
CDN Bundle (incl. Logs, Metrics) - uncompressed	92.19 kB	-	-
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed	147.88 kB	-	-
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed	217 kB	+0.05%	+88 B 🔺
CDN Bundle (incl. Tracing, Replay) - uncompressed	262.99 kB	+0.04%	+88 B 🔺
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed	266.74 kB	+0.04%	+88 B 🔺
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	276.69 kB	+0.04%	+88 B 🔺
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed	280.42 kB	+0.04%	+88 B 🔺
@sentry/nextjs (client)	50.05 kB	-	-
@sentry/sveltekit (client)	45.71 kB	-	-
@sentry/core/server	75.94 kB	-	-
@sentry/core/browser	63.09 kB	-	-
@sentry/node-core	61.69 kB	-0.01%	-1 B 🔽
@sentry/node	130.4 kB	-	-
@sentry/node - without tracing	74.06 kB	+0.01%	+3 B 🔺
@sentry/aws-serverless	86.26 kB	-0.01%	-1 B 🔽
@sentry/cloudflare (withSentry) - minified	171.85 kB	-	-
@sentry/cloudflare (withSentry)	429.49 kB	-	-

View base workflow run