fix(browser): Ensure standalone CLS and LCP spans have traceId of pageload span

dev-packages/browser-integration-tests/suites/tracing/metrics/web-vitals-cls-standalone-spans/test.ts

@@ -348,10 +348,10 @@ sentryTest(
 sentryTest('sends CLS of the initial page when soft-navigating to a new page', async ({ getLocalTestUrl, page }) => {
   const url = await getLocalTestUrl({ testDir: __dirname });
 
-  const eventData = await getFirstSentryEnvelopeRequest<SentryEvent>(page, url);
+  const pageloadEventData = await getFirstSentryEnvelopeRequest<SentryEvent>(page, url);
 
-  expect(eventData.type).toBe('transaction');
-  expect(eventData.contexts?.trace?.op).toBe('pageload');
+  expect(pageloadEventData.type).toBe('transaction');
+  expect(pageloadEventData.contexts?.trace?.op).toBe('pageload');
 
   const spanEnvelopePromise = getMultipleSentryEnvelopeRequests<SpanEnvelope>(
     page,
@@ -364,12 +364,16 @@ sentryTest('sends CLS of the initial page when soft-navigating to a new page', a
 
   await page.goto(`${url}#soft-navigation`);
 
+  const pageloadTraceId = pageloadEventData.contexts?.trace?.trace_id;
+  expect(pageloadTraceId).toMatch(/[a-f0-9]{32}/);
+
   const spanEnvelope = (await spanEnvelopePromise)[0];
   const spanEnvelopeItem = spanEnvelope[1][0][1];
   // Flakey value dependent on timings -> we check for a range
   expect(spanEnvelopeItem.measurements?.cls?.value).toBeGreaterThan(0.05);
   expect(spanEnvelopeItem.measurements?.cls?.value).toBeLessThan(0.15);
-  expect(spanEnvelopeItem.data?.['sentry.pageload.span_id']).toMatch(/[a-f0-9]{16}/);
+  expect(spanEnvelopeItem.data?.['sentry.pageload.span_id']).toBe(pageloadEventData.contexts?.trace?.span_id);
+  expect(spanEnvelopeItem.trace_id).toEqual(pageloadTraceId);
 });
 
 sentryTest("doesn't send further CLS after the first navigation", async ({ getLocalTestUrl, page }) => {

dev-packages/browser-integration-tests/suites/tracing/metrics/web-vitals-lcp-standalone-spans/test.ts

@@ -3,10 +3,12 @@ import { expect } from '@playwright/test';
 import type { Event as SentryEvent, EventEnvelope, SpanEnvelope } from '@sentry/core';
 import { sentryTest } from '../../../../utils/fixtures';
 import {
+  envelopeRequestParser,
   getFirstSentryEnvelopeRequest,
   getMultipleSentryEnvelopeRequests,
   properFullEnvelopeRequestParser,
   shouldSkipTracingTest,
+  waitForTransactionRequest,
 } from '../../../../utils/helpers';
 
 sentryTest.beforeEach(async ({ browserName, page }) => {
@@ -31,6 +33,8 @@ sentryTest('captures LCP vital as a standalone span', async ({ getLocalTestUrl,
     properFullEnvelopeRequestParser,
   );
 
+  const pageloadEnvelopePromise = waitForTransactionRequest(page, e => e.contexts?.trace?.op === 'pageload');
+
   page.route('**', route => route.continue());
   page.route('**/my/image.png', async (route: Route) => {
     return route.fulfill({
@@ -47,10 +51,14 @@ sentryTest('captures LCP vital as a standalone span', async ({ getLocalTestUrl,
   await hidePage(page);
 
   const spanEnvelope = (await spanEnvelopePromise)[0];
+  const pageloadTransactionEvent = envelopeRequestParser(await pageloadEnvelopePromise);
 
   const spanEnvelopeHeaders = spanEnvelope[0];
   const spanEnvelopeItem = spanEnvelope[1][0][1];
 
+  const pageloadTraceId = pageloadTransactionEvent.contexts?.trace?.trace_id;
+  expect(pageloadTraceId).toMatch(/[a-f0-9]{32}/);
+
   expect(spanEnvelopeItem).toEqual({
     data: {
       'sentry.exclusive_time': 0,
@@ -80,7 +88,7 @@ sentryTest('captures LCP vital as a standalone span', async ({ getLocalTestUrl,
     segment_id: expect.stringMatching(/[a-f0-9]{16}/),
     start_timestamp: expect.any(Number),
     timestamp: spanEnvelopeItem.start_timestamp, // LCP is a point-in-time metric
-    trace_id: expect.stringMatching(/[a-f0-9]{32}/),
+    trace_id: pageloadTraceId,
   });
 
   // LCP value should be greater than 0
@@ -95,7 +103,6 @@ sentryTest('captures LCP vital as a standalone span', async ({ getLocalTestUrl,
       sampled: 'true',
       trace_id: spanEnvelopeItem.trace_id,
       sample_rand: expect.any(String),
-      // no transaction, because span source is URL
     },
   });
 });
@@ -152,10 +159,10 @@ sentryTest('sends LCP of the initial page when soft-navigating to a new page', a
 
   const url = await getLocalTestUrl({ testDir: __dirname });
 
-  const eventData = await getFirstSentryEnvelopeRequest<SentryEvent>(page, url);
+  const pageloadEventData = await getFirstSentryEnvelopeRequest<SentryEvent>(page, url);
 
-  expect(eventData.type).toBe('transaction');
-  expect(eventData.contexts?.trace?.op).toBe('pageload');
+  expect(pageloadEventData.type).toBe('transaction');
+  expect(pageloadEventData.contexts?.trace?.op).toBe('pageload');
 
   const spanEnvelopePromise = getMultipleSentryEnvelopeRequests<SpanEnvelope>(
     page,
@@ -173,7 +180,8 @@ sentryTest('sends LCP of the initial page when soft-navigating to a new page', a
   const spanEnvelopeItem = spanEnvelope[1][0][1];
 
   expect(spanEnvelopeItem.measurements?.lcp?.value).toBeGreaterThan(0);
-  expect(spanEnvelopeItem.data?.['sentry.pageload.span_id']).toMatch(/[a-f0-9]{16}/);
+  expect(spanEnvelopeItem.data?.['sentry.pageload.span_id']).toBe(pageloadEventData.contexts?.trace?.span_id);
+  expect(spanEnvelopeItem.trace_id).toBe(pageloadEventData.contexts?.trace?.trace_id);
 });
 
 sentryTest("doesn't send further LCP after the first navigation", async ({ getLocalTestUrl, page }) => {

packages/browser-utils/src/metrics/cls.ts

@@ -72,7 +72,7 @@ export function trackClsAsStandaloneSpan(): void {
       return;
     }
 
-    const unsubscribeStartNavigation = client.on('startNavigationSpan', (_, options) => {
+    const unsubscribeStartNavigation = client.on('beforeStartNavigationSpan', (_, options) => {
       // we only want to collect LCP if we actually navigate. Redirects should be ignored.
       if (!options?.isRedirect) {
         _collectClsOnce();

packages/browser-utils/src/metrics/lcp.ts

@@ -72,7 +72,7 @@ export function trackLcpAsStandaloneSpan(): void {
       return;
     }
 
-    const unsubscribeStartNavigation = client.on('startNavigationSpan', (_, options) => {
+    const unsubscribeStartNavigation = client.on('beforeStartNavigationSpan', (_, options) => {
       // we only want to collect LCP if we actually navigate. Redirects should be ignored.
       if (!options?.isRedirect) {
         _collectLcpOnce();