From d25345e39c18a344b1b8c0a44c4a11ea4cfaaa0f Mon Sep 17 00:00:00 2001
From: Francesco Novy <francesco.novy@sentry.io>
Date: Thu, 9 Jan 2025 15:11:21 +0100
Subject: [PATCH 1/7] ref(core): Ensure non-sampled spans are NonRecordingSpans

---
 .../src/tracing/browserTracingIntegration.ts  |  48 ++++-----
 .../tracing/browserTracingIntegration.test.ts | 100 +++++++++++++-----
 packages/core/src/tracing/trace.ts            |  33 ++++--
 3 files changed, 124 insertions(+), 57 deletions(-)

diff --git a/packages/browser/src/tracing/browserTracingIntegration.ts b/packages/browser/src/tracing/browserTracingIntegration.ts
index f4ab605be9c2..2e761d263424 100644
--- a/packages/browser/src/tracing/browserTracingIntegration.ts
+++ b/packages/browser/src/tracing/browserTracingIntegration.ts
@@ -24,7 +24,6 @@ import {
   getDynamicSamplingContextFromSpan,
   getIsolationScope,
   getLocationHref,
-  getRootSpan,
   logger,
   propagationContextFromHeaders,
   registerSpanErrorInstrumentation,
@@ -276,6 +275,15 @@ export const browserTracingIntegration = ((_options: Partial<BrowserTracingOptio
         _collectWebVitals();
         addPerformanceEntries(span, { recordClsOnPageloadSpan: !enableStandaloneClsSpans });
         setActiveIdleSpan(client, undefined);
+
+        // Ensure that DSC is updated with possibly final transaction etc.
+        const scope = getCurrentScope();
+        const oldPropagationContext = scope.getPropagationContext();
+
+        scope.setPropagationContext({
+          ...oldPropagationContext,
+          dsc: getDynamicSamplingContextFromSpan(span),
+        });
       },
     });
     setActiveIdleSpan(client, idleSpan);
@@ -293,6 +301,21 @@ export const browserTracingIntegration = ((_options: Partial<BrowserTracingOptio
 
       emitFinish();
     }
+
+    // A trace should to stay the consistent over the entire time span of one route.
+    // Therefore, when the initial pageload or navigation root span ends, we update the
+    // scope's propagation context to keep span-specific attributes like the `sampled` decision and
+    // the dynamic sampling context valid, even after the root span has ended.
+    // This ensures that the trace data is consistent for the entire duration of the route.
+    const scope = getCurrentScope();
+    const oldPropagationContext = scope.getPropagationContext();
+
+    scope.setPropagationContext({
+      ...oldPropagationContext,
+      traceId: idleSpan.spanContext().traceId,
+      sampled: spanIsSampled(idleSpan),
+      dsc: getDynamicSamplingContextFromSpan(idleSpan),
+    });
   }
 
   return {
@@ -341,27 +364,6 @@ export const browserTracingIntegration = ((_options: Partial<BrowserTracingOptio
         });
       });
 
-      // A trace should to stay the consistent over the entire time span of one route.
-      // Therefore, when the initial pageload or navigation root span ends, we update the
-      // scope's propagation context to keep span-specific attributes like the `sampled` decision and
-      // the dynamic sampling context valid, even after the root span has ended.
-      // This ensures that the trace data is consistent for the entire duration of the route.
-      client.on('spanEnd', span => {
-        const op = spanToJSON(span).op;
-        if (span !== getRootSpan(span) || (op !== 'navigation' && op !== 'pageload')) {
-          return;
-        }
-
-        const scope = getCurrentScope();
-        const oldPropagationContext = scope.getPropagationContext();
-
-        scope.setPropagationContext({
-          ...oldPropagationContext,
-          sampled: oldPropagationContext.sampled !== undefined ? oldPropagationContext.sampled : spanIsSampled(span),
-          dsc: oldPropagationContext.dsc || getDynamicSamplingContextFromSpan(span),
-        });
-      });
-
       if (WINDOW.location) {
         if (instrumentPageLoad) {
           startBrowserTracingPageLoadSpan(client, {
@@ -453,10 +455,8 @@ export function startBrowserTracingPageLoadSpan(
  */
 export function startBrowserTracingNavigationSpan(client: Client, spanOptions: StartSpanOptions): Span | undefined {
   getIsolationScope().setPropagationContext({ traceId: generateTraceId() });
-  getCurrentScope().setPropagationContext({ traceId: generateTraceId() });
 
   client.emit('startNavigationSpan', spanOptions);
-
   getCurrentScope().setTransactionName(spanOptions.name);
 
   return getActiveIdleSpan(client);
diff --git a/packages/browser/test/tracing/browserTracingIntegration.test.ts b/packages/browser/test/tracing/browserTracingIntegration.test.ts
index 3e9d2354a532..11495eae8ae1 100644
--- a/packages/browser/test/tracing/browserTracingIntegration.test.ts
+++ b/packages/browser/test/tracing/browserTracingIntegration.test.ts
@@ -20,15 +20,18 @@ import {
   SEMANTIC_ATTRIBUTE_SENTRY_ORIGIN,
   SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE,
   SEMANTIC_ATTRIBUTE_SENTRY_SOURCE,
+  SentryNonRecordingSpan,
   TRACING_DEFAULTS,
   getActiveSpan,
   getCurrentScope,
   getDynamicSamplingContextFromSpan,
   getIsolationScope,
+  getTraceData,
   setCurrentClient,
   spanIsSampled,
   spanToJSON,
   startInactiveSpan,
+  updateSpanName,
 } from '@sentry/core';
 import type { Span, StartSpanOptions } from '@sentry/core';
 import { JSDOM } from 'jsdom';
@@ -265,6 +268,10 @@ describe('browserTracingIntegration', () => {
 
       expect(span).toBeDefined();
       expect(spanIsSampled(span!)).toBe(false);
+
+      // Ensure getTraceData is correct in this case
+      const traceData = getTraceData();
+      expect(traceData['sentry-trace']).toEqual(`${span?.spanContext().traceId}-${span?.spanContext().spanId}-0`);
     });
 
     it('works with integration setup', () => {
@@ -365,7 +372,7 @@ describe('browserTracingIntegration', () => {
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          tracesSampleRate: 0,
+          tracesSampleRate: 1,
           integrations: [
             browserTracingIntegration({
               instrumentPageLoad: false,
@@ -378,9 +385,7 @@ describe('browserTracingIntegration', () => {
       setCurrentClient(client);
       client.init();
 
-      startBrowserTracingPageLoadSpan(client, { name: 'test span' });
-
-      const pageloadSpan = getActiveSpan();
+      const pageloadSpan = startBrowserTracingPageLoadSpan(client, { name: 'test span' });
 
       expect(spanToJSON(pageloadSpan!).op).toBe('test op');
     });
@@ -408,7 +413,7 @@ describe('browserTracingIntegration', () => {
 
     const client = new BrowserClient(
       getDefaultBrowserClientOptions({
-        tracesSampleRate: 0,
+        tracesSampleRate: 1,
         integrations: [
           browserTracingIntegration({
             instrumentPageLoad: false,
@@ -458,6 +463,10 @@ describe('browserTracingIntegration', () => {
 
       expect(span).toBeDefined();
       expect(spanIsSampled(span!)).toBe(false);
+
+      // Ensure getTraceData is correct in this case
+      const traceData = getTraceData();
+      expect(traceData['sentry-trace']).toEqual(`${span?.spanContext().traceId}-${span?.spanContext().spanId}-0`);
     });
 
     it('works with integration setup', () => {
@@ -562,7 +571,7 @@ describe('browserTracingIntegration', () => {
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          tracesSampleRate: 0,
+          tracesSampleRate: 1,
           integrations: [
             browserTracingIntegration({
               instrumentPageLoad: false,
@@ -575,9 +584,7 @@ describe('browserTracingIntegration', () => {
       setCurrentClient(client);
       client.init();
 
-      startBrowserTracingNavigationSpan(client, { name: 'test span' });
-
-      const navigationSpan = getActiveSpan();
+      const navigationSpan = startBrowserTracingNavigationSpan(client, { name: 'test span' });
 
       expect(spanToJSON(navigationSpan!).op).toBe('test op');
     });
@@ -590,7 +597,7 @@ describe('browserTracingIntegration', () => {
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          tracesSampleRate: 0,
+          tracesSampleRate: 1,
           integrations: [
             browserTracingIntegration({
               instrumentPageLoad: false,
@@ -628,7 +635,7 @@ describe('browserTracingIntegration', () => {
     it("updates the scopes' propagationContexts on a navigation", () => {
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          integrations: [browserTracingIntegration()],
+          integrations: [browserTracingIntegration({ instrumentPageLoad: false })],
         }),
       );
       setCurrentClient(client);
@@ -637,7 +644,8 @@ describe('browserTracingIntegration', () => {
       const oldIsolationScopePropCtx = getIsolationScope().getPropagationContext();
       const oldCurrentScopePropCtx = getCurrentScope().getPropagationContext();
 
-      startBrowserTracingNavigationSpan(client, { name: 'test navigation span' });
+      const span = startBrowserTracingNavigationSpan(client, { name: 'test navigation span' });
+      const traceId = span!.spanContext().traceId;
 
       const newIsolationScopePropCtx = getIsolationScope().getPropagationContext();
       const newCurrentScopePropCtx = getCurrentScope().getPropagationContext();
@@ -649,7 +657,14 @@ describe('browserTracingIntegration', () => {
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
       });
       expect(newCurrentScopePropCtx).toEqual({
-        traceId: expect.stringMatching(/[a-f0-9]{32}/),
+        traceId,
+        sampled: false,
+        dsc: {
+          environment: 'production',
+          public_key: 'examplePublicKey',
+          sample_rate: '0',
+          trace_id: traceId,
+        },
       });
       expect(newIsolationScopePropCtx).toEqual({
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
@@ -657,6 +672,22 @@ describe('browserTracingIntegration', () => {
 
       expect(newIsolationScopePropCtx.traceId).not.toEqual(oldIsolationScopePropCtx.traceId);
       expect(newCurrentScopePropCtx.traceId).not.toEqual(oldCurrentScopePropCtx.traceId);
+
+      const span2 = startBrowserTracingNavigationSpan(client, { name: 'test navigation span 2' });
+      const traceId2 = span2!.spanContext().traceId;
+      expect(traceId2).not.toEqual(traceId);
+
+      const newCurrentScopePropCtx2 = getCurrentScope().getPropagationContext();
+      expect(newCurrentScopePropCtx2).toEqual({
+        traceId: traceId2,
+        sampled: false,
+        dsc: {
+          environment: 'production',
+          public_key: 'examplePublicKey',
+          sample_rate: '0',
+          trace_id: traceId2,
+        },
+      });
     });
 
     it("saves the span's positive sampling decision and its DSC on the propagationContext when the span finishes", () => {
@@ -677,8 +708,18 @@ describe('browserTracingIntegration', () => {
       const propCtxBeforeEnd = getCurrentScope().getPropagationContext();
       expect(propCtxBeforeEnd).toStrictEqual({
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
+        sampled: true,
+        dsc: {
+          environment: 'production',
+          public_key: 'examplePublicKey',
+          sample_rate: '1',
+          sampled: 'true',
+          transaction: 'mySpan',
+          trace_id: propCtxBeforeEnd.traceId,
+        },
       });
 
+      updateSpanName(navigationSpan!, 'mySpan2');
       navigationSpan!.end();
 
       const propCtxAfterEnd = getCurrentScope().getPropagationContext();
@@ -690,7 +731,7 @@ describe('browserTracingIntegration', () => {
           public_key: 'examplePublicKey',
           sample_rate: '1',
           sampled: 'true',
-          transaction: 'mySpan',
+          transaction: 'mySpan2',
           trace_id: propCtxBeforeEnd.traceId,
         },
       });
@@ -714,6 +755,15 @@ describe('browserTracingIntegration', () => {
       const propCtxBeforeEnd = getCurrentScope().getPropagationContext();
       expect(propCtxBeforeEnd).toStrictEqual({
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
+        sampled: false,
+        dsc: {
+          environment: 'production',
+          public_key: 'examplePublicKey',
+          sample_rate: '0',
+          sampled: 'false',
+          transaction: 'mySpan',
+          trace_id: propCtxBeforeEnd.traceId,
+        },
       });
 
       navigationSpan!.end();
@@ -758,11 +808,8 @@ describe('browserTracingIntegration', () => {
       const dynamicSamplingContext = getDynamicSamplingContextFromSpan(idleSpan!);
       const propagationContext = getCurrentScope().getPropagationContext();
 
-      // Span is correct
-      expect(spanToJSON(idleSpan).op).toBe('pageload');
-      expect(spanToJSON(idleSpan).trace_id).toEqual('12312012123120121231201212312012');
-      expect(spanToJSON(idleSpan).parent_span_id).toEqual('1121201211212012');
-      expect(spanIsSampled(idleSpan)).toBe(false);
+      // Span is non-recording
+      expect(idleSpan instanceof SentryNonRecordingSpan).toBe(true);
 
       expect(dynamicSamplingContext).toBeDefined();
       expect(dynamicSamplingContext).toStrictEqual({ release: '2.1.14' });
@@ -770,6 +817,10 @@ describe('browserTracingIntegration', () => {
       // Propagation context keeps the meta tag trace data for later events on the same route to add them to the trace
       expect(propagationContext.traceId).toEqual('12312012123120121231201212312012');
       expect(propagationContext.parentSpanId).toEqual('1121201211212012');
+
+      // Ensure getTraceData is correct in this case
+      const traceData = getTraceData();
+      expect(traceData['sentry-trace']).toMatch(/12312012123120121231201212312012-[a-f0-9]{16}-0/);
     });
 
     it('puts frozen Dynamic Sampling Context on pageload span if sentry-trace data and only 3rd party baggage is present', () => {
@@ -795,11 +846,8 @@ describe('browserTracingIntegration', () => {
       const dynamicSamplingContext = getDynamicSamplingContextFromSpan(idleSpan);
       const propagationContext = getCurrentScope().getPropagationContext();
 
-      // Span is correct
-      expect(spanToJSON(idleSpan).op).toBe('pageload');
-      expect(spanToJSON(idleSpan).trace_id).toEqual('12312012123120121231201212312012');
-      expect(spanToJSON(idleSpan).parent_span_id).toEqual('1121201211212012');
-      expect(spanIsSampled(idleSpan)).toBe(false);
+      // Span is NonRecordingSpan
+      expect(idleSpan instanceof SentryNonRecordingSpan).toBe(true);
 
       expect(dynamicSamplingContext).toBeDefined();
       expect(dynamicSamplingContext).toStrictEqual({});
@@ -807,6 +855,10 @@ describe('browserTracingIntegration', () => {
       // Propagation context keeps the meta tag trace data for later events on the same route to add them to the trace
       expect(propagationContext.traceId).toEqual('12312012123120121231201212312012');
       expect(propagationContext.parentSpanId).toEqual('1121201211212012');
+
+      // Ensure getTraceData is correct in this case
+      const traceData = getTraceData();
+      expect(traceData['sentry-trace']).toMatch(/12312012123120121231201212312012-[a-f0-9]{16}-0/);
     });
 
     it('ignores the meta tag data for navigation spans', () => {
diff --git a/packages/core/src/tracing/trace.ts b/packages/core/src/tracing/trace.ts
index 28b9654d5266..d75c15ee1b77 100644
--- a/packages/core/src/tracing/trace.ts
+++ b/packages/core/src/tracing/trace.ts
@@ -391,7 +391,11 @@ function getAcs(): AsyncContextStrategy {
   return getAsyncContextStrategy(carrier);
 }
 
-function _startRootSpan(spanArguments: SentrySpanArguments, scope: Scope, parentSampled?: boolean): SentrySpan {
+function _startRootSpan(
+  spanArguments: SentrySpanArguments,
+  scope: Scope,
+  parentSampled?: boolean,
+): SentrySpan | SentryNonRecordingSpan {
   const client = getClient();
   const options: Partial<ClientOptions> = client?.getOptions() || {};
 
@@ -408,14 +412,25 @@ function _startRootSpan(spanArguments: SentrySpanArguments, scope: Scope, parent
         },
       });
 
-  const rootSpan = new SentrySpan({
-    ...spanArguments,
-    attributes: {
-      [SEMANTIC_ATTRIBUTE_SENTRY_SOURCE]: 'custom',
-      ...spanArguments.attributes,
-    },
-    sampled,
-  });
+  const rootSpan = sampled
+    ? new SentrySpan({
+        ...spanArguments,
+        attributes: {
+          [SEMANTIC_ATTRIBUTE_SENTRY_SOURCE]: 'custom',
+          ...spanArguments.attributes,
+        },
+        sampled,
+      })
+    : new SentryNonRecordingSpan({ traceId: spanArguments.traceId });
+
+  if (!sampled) {
+    const dsc = {
+      sample_rate: sampleRate !== undefined ? `${sampleRate}` : undefined,
+      transaction: name,
+      ...getDynamicSamplingContextFromSpan(rootSpan),
+    } satisfies Partial<DynamicSamplingContext>;
+    freezeDscOnSpan(rootSpan, dsc);
+  }
 
   if (!sampled && client) {
     DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');

From 85b92cde55a69119017f94e4f318d7447d1f0b48 Mon Sep 17 00:00:00 2001
From: Francesco Novy <francesco.novy@sentry.io>
Date: Fri, 10 Jan 2025 10:52:29 +0100
Subject: [PATCH 2/7] revert tests

---
 .../tracing/browserTracingIntegration.test.ts | 100 +++++-------------
 1 file changed, 24 insertions(+), 76 deletions(-)

diff --git a/packages/browser/test/tracing/browserTracingIntegration.test.ts b/packages/browser/test/tracing/browserTracingIntegration.test.ts
index 11495eae8ae1..3e9d2354a532 100644
--- a/packages/browser/test/tracing/browserTracingIntegration.test.ts
+++ b/packages/browser/test/tracing/browserTracingIntegration.test.ts
@@ -20,18 +20,15 @@ import {
   SEMANTIC_ATTRIBUTE_SENTRY_ORIGIN,
   SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE,
   SEMANTIC_ATTRIBUTE_SENTRY_SOURCE,
-  SentryNonRecordingSpan,
   TRACING_DEFAULTS,
   getActiveSpan,
   getCurrentScope,
   getDynamicSamplingContextFromSpan,
   getIsolationScope,
-  getTraceData,
   setCurrentClient,
   spanIsSampled,
   spanToJSON,
   startInactiveSpan,
-  updateSpanName,
 } from '@sentry/core';
 import type { Span, StartSpanOptions } from '@sentry/core';
 import { JSDOM } from 'jsdom';
@@ -268,10 +265,6 @@ describe('browserTracingIntegration', () => {
 
       expect(span).toBeDefined();
       expect(spanIsSampled(span!)).toBe(false);
-
-      // Ensure getTraceData is correct in this case
-      const traceData = getTraceData();
-      expect(traceData['sentry-trace']).toEqual(`${span?.spanContext().traceId}-${span?.spanContext().spanId}-0`);
     });
 
     it('works with integration setup', () => {
@@ -372,7 +365,7 @@ describe('browserTracingIntegration', () => {
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          tracesSampleRate: 1,
+          tracesSampleRate: 0,
           integrations: [
             browserTracingIntegration({
               instrumentPageLoad: false,
@@ -385,7 +378,9 @@ describe('browserTracingIntegration', () => {
       setCurrentClient(client);
       client.init();
 
-      const pageloadSpan = startBrowserTracingPageLoadSpan(client, { name: 'test span' });
+      startBrowserTracingPageLoadSpan(client, { name: 'test span' });
+
+      const pageloadSpan = getActiveSpan();
 
       expect(spanToJSON(pageloadSpan!).op).toBe('test op');
     });
@@ -413,7 +408,7 @@ describe('browserTracingIntegration', () => {
 
     const client = new BrowserClient(
       getDefaultBrowserClientOptions({
-        tracesSampleRate: 1,
+        tracesSampleRate: 0,
         integrations: [
           browserTracingIntegration({
             instrumentPageLoad: false,
@@ -463,10 +458,6 @@ describe('browserTracingIntegration', () => {
 
       expect(span).toBeDefined();
       expect(spanIsSampled(span!)).toBe(false);
-
-      // Ensure getTraceData is correct in this case
-      const traceData = getTraceData();
-      expect(traceData['sentry-trace']).toEqual(`${span?.spanContext().traceId}-${span?.spanContext().spanId}-0`);
     });
 
     it('works with integration setup', () => {
@@ -571,7 +562,7 @@ describe('browserTracingIntegration', () => {
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          tracesSampleRate: 1,
+          tracesSampleRate: 0,
           integrations: [
             browserTracingIntegration({
               instrumentPageLoad: false,
@@ -584,7 +575,9 @@ describe('browserTracingIntegration', () => {
       setCurrentClient(client);
       client.init();
 
-      const navigationSpan = startBrowserTracingNavigationSpan(client, { name: 'test span' });
+      startBrowserTracingNavigationSpan(client, { name: 'test span' });
+
+      const navigationSpan = getActiveSpan();
 
       expect(spanToJSON(navigationSpan!).op).toBe('test op');
     });
@@ -597,7 +590,7 @@ describe('browserTracingIntegration', () => {
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          tracesSampleRate: 1,
+          tracesSampleRate: 0,
           integrations: [
             browserTracingIntegration({
               instrumentPageLoad: false,
@@ -635,7 +628,7 @@ describe('browserTracingIntegration', () => {
     it("updates the scopes' propagationContexts on a navigation", () => {
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          integrations: [browserTracingIntegration({ instrumentPageLoad: false })],
+          integrations: [browserTracingIntegration()],
         }),
       );
       setCurrentClient(client);
@@ -644,8 +637,7 @@ describe('browserTracingIntegration', () => {
       const oldIsolationScopePropCtx = getIsolationScope().getPropagationContext();
       const oldCurrentScopePropCtx = getCurrentScope().getPropagationContext();
 
-      const span = startBrowserTracingNavigationSpan(client, { name: 'test navigation span' });
-      const traceId = span!.spanContext().traceId;
+      startBrowserTracingNavigationSpan(client, { name: 'test navigation span' });
 
       const newIsolationScopePropCtx = getIsolationScope().getPropagationContext();
       const newCurrentScopePropCtx = getCurrentScope().getPropagationContext();
@@ -657,14 +649,7 @@ describe('browserTracingIntegration', () => {
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
       });
       expect(newCurrentScopePropCtx).toEqual({
-        traceId,
-        sampled: false,
-        dsc: {
-          environment: 'production',
-          public_key: 'examplePublicKey',
-          sample_rate: '0',
-          trace_id: traceId,
-        },
+        traceId: expect.stringMatching(/[a-f0-9]{32}/),
       });
       expect(newIsolationScopePropCtx).toEqual({
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
@@ -672,22 +657,6 @@ describe('browserTracingIntegration', () => {
 
       expect(newIsolationScopePropCtx.traceId).not.toEqual(oldIsolationScopePropCtx.traceId);
       expect(newCurrentScopePropCtx.traceId).not.toEqual(oldCurrentScopePropCtx.traceId);
-
-      const span2 = startBrowserTracingNavigationSpan(client, { name: 'test navigation span 2' });
-      const traceId2 = span2!.spanContext().traceId;
-      expect(traceId2).not.toEqual(traceId);
-
-      const newCurrentScopePropCtx2 = getCurrentScope().getPropagationContext();
-      expect(newCurrentScopePropCtx2).toEqual({
-        traceId: traceId2,
-        sampled: false,
-        dsc: {
-          environment: 'production',
-          public_key: 'examplePublicKey',
-          sample_rate: '0',
-          trace_id: traceId2,
-        },
-      });
     });
 
     it("saves the span's positive sampling decision and its DSC on the propagationContext when the span finishes", () => {
@@ -708,18 +677,8 @@ describe('browserTracingIntegration', () => {
       const propCtxBeforeEnd = getCurrentScope().getPropagationContext();
       expect(propCtxBeforeEnd).toStrictEqual({
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
-        sampled: true,
-        dsc: {
-          environment: 'production',
-          public_key: 'examplePublicKey',
-          sample_rate: '1',
-          sampled: 'true',
-          transaction: 'mySpan',
-          trace_id: propCtxBeforeEnd.traceId,
-        },
       });
 
-      updateSpanName(navigationSpan!, 'mySpan2');
       navigationSpan!.end();
 
       const propCtxAfterEnd = getCurrentScope().getPropagationContext();
@@ -731,7 +690,7 @@ describe('browserTracingIntegration', () => {
           public_key: 'examplePublicKey',
           sample_rate: '1',
           sampled: 'true',
-          transaction: 'mySpan2',
+          transaction: 'mySpan',
           trace_id: propCtxBeforeEnd.traceId,
         },
       });
@@ -755,15 +714,6 @@ describe('browserTracingIntegration', () => {
       const propCtxBeforeEnd = getCurrentScope().getPropagationContext();
       expect(propCtxBeforeEnd).toStrictEqual({
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
-        sampled: false,
-        dsc: {
-          environment: 'production',
-          public_key: 'examplePublicKey',
-          sample_rate: '0',
-          sampled: 'false',
-          transaction: 'mySpan',
-          trace_id: propCtxBeforeEnd.traceId,
-        },
       });
 
       navigationSpan!.end();
@@ -808,8 +758,11 @@ describe('browserTracingIntegration', () => {
       const dynamicSamplingContext = getDynamicSamplingContextFromSpan(idleSpan!);
       const propagationContext = getCurrentScope().getPropagationContext();
 
-      // Span is non-recording
-      expect(idleSpan instanceof SentryNonRecordingSpan).toBe(true);
+      // Span is correct
+      expect(spanToJSON(idleSpan).op).toBe('pageload');
+      expect(spanToJSON(idleSpan).trace_id).toEqual('12312012123120121231201212312012');
+      expect(spanToJSON(idleSpan).parent_span_id).toEqual('1121201211212012');
+      expect(spanIsSampled(idleSpan)).toBe(false);
 
       expect(dynamicSamplingContext).toBeDefined();
       expect(dynamicSamplingContext).toStrictEqual({ release: '2.1.14' });
@@ -817,10 +770,6 @@ describe('browserTracingIntegration', () => {
       // Propagation context keeps the meta tag trace data for later events on the same route to add them to the trace
       expect(propagationContext.traceId).toEqual('12312012123120121231201212312012');
       expect(propagationContext.parentSpanId).toEqual('1121201211212012');
-
-      // Ensure getTraceData is correct in this case
-      const traceData = getTraceData();
-      expect(traceData['sentry-trace']).toMatch(/12312012123120121231201212312012-[a-f0-9]{16}-0/);
     });
 
     it('puts frozen Dynamic Sampling Context on pageload span if sentry-trace data and only 3rd party baggage is present', () => {
@@ -846,8 +795,11 @@ describe('browserTracingIntegration', () => {
       const dynamicSamplingContext = getDynamicSamplingContextFromSpan(idleSpan);
       const propagationContext = getCurrentScope().getPropagationContext();
 
-      // Span is NonRecordingSpan
-      expect(idleSpan instanceof SentryNonRecordingSpan).toBe(true);
+      // Span is correct
+      expect(spanToJSON(idleSpan).op).toBe('pageload');
+      expect(spanToJSON(idleSpan).trace_id).toEqual('12312012123120121231201212312012');
+      expect(spanToJSON(idleSpan).parent_span_id).toEqual('1121201211212012');
+      expect(spanIsSampled(idleSpan)).toBe(false);
 
       expect(dynamicSamplingContext).toBeDefined();
       expect(dynamicSamplingContext).toStrictEqual({});
@@ -855,10 +807,6 @@ describe('browserTracingIntegration', () => {
       // Propagation context keeps the meta tag trace data for later events on the same route to add them to the trace
       expect(propagationContext.traceId).toEqual('12312012123120121231201212312012');
       expect(propagationContext.parentSpanId).toEqual('1121201211212012');
-
-      // Ensure getTraceData is correct in this case
-      const traceData = getTraceData();
-      expect(traceData['sentry-trace']).toMatch(/12312012123120121231201212312012-[a-f0-9]{16}-0/);
     });
 
     it('ignores the meta tag data for navigation spans', () => {

From afc1878e7e0c26af5cc1e4e2bc54da2683427670 Mon Sep 17 00:00:00 2001
From: Francesco Novy <francesco.novy@sentry.io>
Date: Fri, 10 Jan 2025 10:56:39 +0100
Subject: [PATCH 3/7] do not set on span start??

---
 .../src/tracing/browserTracingIntegration.ts    | 17 ++---------------
 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/packages/browser/src/tracing/browserTracingIntegration.ts b/packages/browser/src/tracing/browserTracingIntegration.ts
index 2e761d263424..bbe0706c6959 100644
--- a/packages/browser/src/tracing/browserTracingIntegration.ts
+++ b/packages/browser/src/tracing/browserTracingIntegration.ts
@@ -282,6 +282,8 @@ export const browserTracingIntegration = ((_options: Partial<BrowserTracingOptio
 
         scope.setPropagationContext({
           ...oldPropagationContext,
+          traceId: idleSpan.spanContext().traceId,
+          sampled: spanIsSampled(idleSpan),
           dsc: getDynamicSamplingContextFromSpan(span),
         });
       },
@@ -301,21 +303,6 @@ export const browserTracingIntegration = ((_options: Partial<BrowserTracingOptio
 
       emitFinish();
     }
-
-    // A trace should to stay the consistent over the entire time span of one route.
-    // Therefore, when the initial pageload or navigation root span ends, we update the
-    // scope's propagation context to keep span-specific attributes like the `sampled` decision and
-    // the dynamic sampling context valid, even after the root span has ended.
-    // This ensures that the trace data is consistent for the entire duration of the route.
-    const scope = getCurrentScope();
-    const oldPropagationContext = scope.getPropagationContext();
-
-    scope.setPropagationContext({
-      ...oldPropagationContext,
-      traceId: idleSpan.spanContext().traceId,
-      sampled: spanIsSampled(idleSpan),
-      dsc: getDynamicSamplingContextFromSpan(idleSpan),
-    });
   }
 
   return {

From 67c175e82ca481105039db4501a199dc1c9ced62 Mon Sep 17 00:00:00 2001
From: Francesco Novy <francesco.novy@sentry.io>
Date: Fri, 10 Jan 2025 10:58:16 +0100
Subject: [PATCH 4/7] WIP changed tests

---
 .../tracing/browserTracingIntegration.test.ts | 73 +++++++++++++------
 1 file changed, 50 insertions(+), 23 deletions(-)

diff --git a/packages/browser/test/tracing/browserTracingIntegration.test.ts b/packages/browser/test/tracing/browserTracingIntegration.test.ts
index 3e9d2354a532..ba840f535a00 100644
--- a/packages/browser/test/tracing/browserTracingIntegration.test.ts
+++ b/packages/browser/test/tracing/browserTracingIntegration.test.ts
@@ -20,15 +20,18 @@ import {
   SEMANTIC_ATTRIBUTE_SENTRY_ORIGIN,
   SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE,
   SEMANTIC_ATTRIBUTE_SENTRY_SOURCE,
+  SentryNonRecordingSpan,
   TRACING_DEFAULTS,
   getActiveSpan,
   getCurrentScope,
   getDynamicSamplingContextFromSpan,
   getIsolationScope,
+  getTraceData,
   setCurrentClient,
   spanIsSampled,
   spanToJSON,
   startInactiveSpan,
+  updateSpanName,
 } from '@sentry/core';
 import type { Span, StartSpanOptions } from '@sentry/core';
 import { JSDOM } from 'jsdom';
@@ -265,6 +268,10 @@ describe('browserTracingIntegration', () => {
 
       expect(span).toBeDefined();
       expect(spanIsSampled(span!)).toBe(false);
+
+      // Ensure getTraceData is correct in this case
+      const traceData = getTraceData();
+      expect(traceData['sentry-trace']).toEqual(`${span?.spanContext().traceId}-${span?.spanContext().spanId}-0`);
     });
 
     it('works with integration setup', () => {
@@ -365,7 +372,7 @@ describe('browserTracingIntegration', () => {
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          tracesSampleRate: 0,
+          tracesSampleRate: 1,
           integrations: [
             browserTracingIntegration({
               instrumentPageLoad: false,
@@ -378,9 +385,7 @@ describe('browserTracingIntegration', () => {
       setCurrentClient(client);
       client.init();
 
-      startBrowserTracingPageLoadSpan(client, { name: 'test span' });
-
-      const pageloadSpan = getActiveSpan();
+      const pageloadSpan = startBrowserTracingPageLoadSpan(client, { name: 'test span' });
 
       expect(spanToJSON(pageloadSpan!).op).toBe('test op');
     });
@@ -408,7 +413,7 @@ describe('browserTracingIntegration', () => {
 
     const client = new BrowserClient(
       getDefaultBrowserClientOptions({
-        tracesSampleRate: 0,
+        tracesSampleRate: 1,
         integrations: [
           browserTracingIntegration({
             instrumentPageLoad: false,
@@ -458,6 +463,10 @@ describe('browserTracingIntegration', () => {
 
       expect(span).toBeDefined();
       expect(spanIsSampled(span!)).toBe(false);
+
+      // Ensure getTraceData is correct in this case
+      const traceData = getTraceData();
+      expect(traceData['sentry-trace']).toEqual(`${span?.spanContext().traceId}-${span?.spanContext().spanId}-0`);
     });
 
     it('works with integration setup', () => {
@@ -562,7 +571,7 @@ describe('browserTracingIntegration', () => {
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          tracesSampleRate: 0,
+          tracesSampleRate: 1,
           integrations: [
             browserTracingIntegration({
               instrumentPageLoad: false,
@@ -575,9 +584,7 @@ describe('browserTracingIntegration', () => {
       setCurrentClient(client);
       client.init();
 
-      startBrowserTracingNavigationSpan(client, { name: 'test span' });
-
-      const navigationSpan = getActiveSpan();
+      const navigationSpan = startBrowserTracingNavigationSpan(client, { name: 'test span' });
 
       expect(spanToJSON(navigationSpan!).op).toBe('test op');
     });
@@ -590,7 +597,7 @@ describe('browserTracingIntegration', () => {
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          tracesSampleRate: 0,
+          tracesSampleRate: 1,
           integrations: [
             browserTracingIntegration({
               instrumentPageLoad: false,
@@ -628,7 +635,7 @@ describe('browserTracingIntegration', () => {
     it("updates the scopes' propagationContexts on a navigation", () => {
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
-          integrations: [browserTracingIntegration()],
+          integrations: [browserTracingIntegration({ instrumentPageLoad: false })],
         }),
       );
       setCurrentClient(client);
@@ -637,7 +644,8 @@ describe('browserTracingIntegration', () => {
       const oldIsolationScopePropCtx = getIsolationScope().getPropagationContext();
       const oldCurrentScopePropCtx = getCurrentScope().getPropagationContext();
 
-      startBrowserTracingNavigationSpan(client, { name: 'test navigation span' });
+      const span = startBrowserTracingNavigationSpan(client, { name: 'test navigation span' });
+      const traceId = span!.spanContext().traceId;
 
       const newIsolationScopePropCtx = getIsolationScope().getPropagationContext();
       const newCurrentScopePropCtx = getCurrentScope().getPropagationContext();
@@ -657,6 +665,22 @@ describe('browserTracingIntegration', () => {
 
       expect(newIsolationScopePropCtx.traceId).not.toEqual(oldIsolationScopePropCtx.traceId);
       expect(newCurrentScopePropCtx.traceId).not.toEqual(oldCurrentScopePropCtx.traceId);
+
+      const span2 = startBrowserTracingNavigationSpan(client, { name: 'test navigation span 2' });
+      const traceId2 = span2!.spanContext().traceId;
+      expect(traceId2).not.toEqual(traceId);
+
+      const newCurrentScopePropCtx2 = getCurrentScope().getPropagationContext();
+      expect(newCurrentScopePropCtx2).toEqual({
+        traceId: traceId2,
+        sampled: false,
+        dsc: {
+          environment: 'production',
+          public_key: 'examplePublicKey',
+          sample_rate: '0',
+          trace_id: traceId2,
+        },
+      });
     });
 
     it("saves the span's positive sampling decision and its DSC on the propagationContext when the span finishes", () => {
@@ -679,6 +703,7 @@ describe('browserTracingIntegration', () => {
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
       });
 
+      updateSpanName(navigationSpan!, 'mySpan2');
       navigationSpan!.end();
 
       const propCtxAfterEnd = getCurrentScope().getPropagationContext();
@@ -690,7 +715,7 @@ describe('browserTracingIntegration', () => {
           public_key: 'examplePublicKey',
           sample_rate: '1',
           sampled: 'true',
-          transaction: 'mySpan',
+          transaction: 'mySpan2',
           trace_id: propCtxBeforeEnd.traceId,
         },
       });
@@ -758,11 +783,8 @@ describe('browserTracingIntegration', () => {
       const dynamicSamplingContext = getDynamicSamplingContextFromSpan(idleSpan!);
       const propagationContext = getCurrentScope().getPropagationContext();
 
-      // Span is correct
-      expect(spanToJSON(idleSpan).op).toBe('pageload');
-      expect(spanToJSON(idleSpan).trace_id).toEqual('12312012123120121231201212312012');
-      expect(spanToJSON(idleSpan).parent_span_id).toEqual('1121201211212012');
-      expect(spanIsSampled(idleSpan)).toBe(false);
+      // Span is non-recording
+      expect(idleSpan instanceof SentryNonRecordingSpan).toBe(true);
 
       expect(dynamicSamplingContext).toBeDefined();
       expect(dynamicSamplingContext).toStrictEqual({ release: '2.1.14' });
@@ -770,6 +792,10 @@ describe('browserTracingIntegration', () => {
       // Propagation context keeps the meta tag trace data for later events on the same route to add them to the trace
       expect(propagationContext.traceId).toEqual('12312012123120121231201212312012');
       expect(propagationContext.parentSpanId).toEqual('1121201211212012');
+
+      // Ensure getTraceData is correct in this case
+      const traceData = getTraceData();
+      expect(traceData['sentry-trace']).toMatch(/12312012123120121231201212312012-[a-f0-9]{16}-0/);
     });
 
     it('puts frozen Dynamic Sampling Context on pageload span if sentry-trace data and only 3rd party baggage is present', () => {
@@ -795,11 +821,8 @@ describe('browserTracingIntegration', () => {
       const dynamicSamplingContext = getDynamicSamplingContextFromSpan(idleSpan);
       const propagationContext = getCurrentScope().getPropagationContext();
 
-      // Span is correct
-      expect(spanToJSON(idleSpan).op).toBe('pageload');
-      expect(spanToJSON(idleSpan).trace_id).toEqual('12312012123120121231201212312012');
-      expect(spanToJSON(idleSpan).parent_span_id).toEqual('1121201211212012');
-      expect(spanIsSampled(idleSpan)).toBe(false);
+      // Span is NonRecordingSpan
+      expect(idleSpan instanceof SentryNonRecordingSpan).toBe(true);
 
       expect(dynamicSamplingContext).toBeDefined();
       expect(dynamicSamplingContext).toStrictEqual({});
@@ -807,6 +830,10 @@ describe('browserTracingIntegration', () => {
       // Propagation context keeps the meta tag trace data for later events on the same route to add them to the trace
       expect(propagationContext.traceId).toEqual('12312012123120121231201212312012');
       expect(propagationContext.parentSpanId).toEqual('1121201211212012');
+
+      // Ensure getTraceData is correct in this case
+      const traceData = getTraceData();
+      expect(traceData['sentry-trace']).toMatch(/12312012123120121231201212312012-[a-f0-9]{16}-0/);
     });
 
     it('ignores the meta tag data for navigation spans', () => {

From a3322370fdc38a419636ef1543ef40a5a8778621 Mon Sep 17 00:00:00 2001
From: Francesco Novy <francesco.novy@sentry.io>
Date: Fri, 10 Jan 2025 11:24:49 +0100
Subject: [PATCH 5/7] fixes

---
 .../src/tracing/browserTracingIntegration.ts  |  19 +++-
 .../tracing/browserTracingIntegration.test.ts |  12 ++
 packages/core/src/tracing/idleSpan.ts         | 106 +++++++++---------
 3 files changed, 85 insertions(+), 52 deletions(-)

diff --git a/packages/browser/src/tracing/browserTracingIntegration.ts b/packages/browser/src/tracing/browserTracingIntegration.ts
index bbe0706c6959..ebd143bc877d 100644
--- a/packages/browser/src/tracing/browserTracingIntegration.ts
+++ b/packages/browser/src/tracing/browserTracingIntegration.ts
@@ -9,7 +9,8 @@ import {
   startTrackingLongTasks,
   startTrackingWebVitals,
 } from '@sentry-internal/browser-utils';
-import type { Client, IntegrationFn, Span, StartSpanOptions, TransactionSource } from '@sentry/core';
+import type { Client, IntegrationFn, Span, StartSpanOptions, TransactionSource} from '@sentry/core';
+import { dropUndefinedKeys } from '@sentry/core';
 import {
   GLOBAL_OBJ,
   SEMANTIC_ATTRIBUTE_SENTRY_IDLE_SPAN_FINISH_REASON,
@@ -303,6 +304,22 @@ export const browserTracingIntegration = ((_options: Partial<BrowserTracingOptio
 
       emitFinish();
     }
+
+    // A trace should to stay the consistent over the entire time span of one route.
+    // Therefore, we update the traceId/sampled properties on the propagation context.
+    // The DSC is only set once the span has ended
+    const scope = getCurrentScope();
+    const oldPropagationContext = scope.getPropagationContext();
+
+    scope.setPropagationContext(
+      dropUndefinedKeys({
+        ...oldPropagationContext,
+        traceId: idleSpan.spanContext().traceId,
+        sampled: spanIsSampled(idleSpan),
+        // Reset the DSC, it should be read from the span while it is active
+        dsc: undefined,
+      }),
+    );
   }
 
   return {
diff --git a/packages/browser/test/tracing/browserTracingIntegration.test.ts b/packages/browser/test/tracing/browserTracingIntegration.test.ts
index ba840f535a00..4ca1f785a895 100644
--- a/packages/browser/test/tracing/browserTracingIntegration.test.ts
+++ b/packages/browser/test/tracing/browserTracingIntegration.test.ts
@@ -658,6 +658,7 @@ describe('browserTracingIntegration', () => {
       });
       expect(newCurrentScopePropCtx).toEqual({
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
+        sampled: false,
       });
       expect(newIsolationScopePropCtx).toEqual({
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
@@ -674,10 +675,19 @@ describe('browserTracingIntegration', () => {
       expect(newCurrentScopePropCtx2).toEqual({
         traceId: traceId2,
         sampled: false,
+      });
+
+      span2?.end();
+
+      const newCurrentScopePropCtx2After = getCurrentScope().getPropagationContext();
+      expect(newCurrentScopePropCtx2After).toEqual({
+        traceId: traceId2,
+        sampled: false,
         dsc: {
           environment: 'production',
           public_key: 'examplePublicKey',
           sample_rate: '0',
+          sampled: 'false',
           trace_id: traceId2,
         },
       });
@@ -701,6 +711,7 @@ describe('browserTracingIntegration', () => {
       const propCtxBeforeEnd = getCurrentScope().getPropagationContext();
       expect(propCtxBeforeEnd).toStrictEqual({
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
+        sampled: true,
       });
 
       updateSpanName(navigationSpan!, 'mySpan2');
@@ -739,6 +750,7 @@ describe('browserTracingIntegration', () => {
       const propCtxBeforeEnd = getCurrentScope().getPropagationContext();
       expect(propCtxBeforeEnd).toStrictEqual({
         traceId: expect.stringMatching(/[a-f0-9]{32}/),
+        sampled: false,
       });
 
       navigationSpan!.end();
diff --git a/packages/core/src/tracing/idleSpan.ts b/packages/core/src/tracing/idleSpan.ts
index 41e336677d2b..a9eab29786d0 100644
--- a/packages/core/src/tracing/idleSpan.ts
+++ b/packages/core/src/tracing/idleSpan.ts
@@ -109,6 +109,59 @@ export function startIdleSpan(startSpanOptions: StartSpanOptions, options: Parti
 
   const client = getClient();
 
+  function patchSpanEnd(span: Span): void {
+    // We patch span.end to ensure we can run some things before the span is ended
+    // eslint-disable-next-line @typescript-eslint/unbound-method
+    span.end = new Proxy(span.end, {
+      apply(target, thisArg, args: Parameters<Span['end']>) {
+        if (beforeSpanEnd) {
+          beforeSpanEnd(span);
+        }
+
+        // If the span is non-recording, nothing more to do here...
+        // This is the case if tracing is enabled but this specific span was not sampled
+        if (thisArg instanceof SentryNonRecordingSpan) {
+          return;
+        }
+
+        // Just ensuring that this keeps working, even if we ever have more arguments here
+        const [definedEndTimestamp, ...rest] = args;
+        const timestamp = definedEndTimestamp || timestampInSeconds();
+        const spanEndTimestamp = spanTimeInputToSeconds(timestamp);
+
+        // Ensure we end with the last span timestamp, if possible
+        const spans = getSpanDescendants(span).filter(child => child !== span);
+
+        // If we have no spans, we just end, nothing else to do here
+        if (!spans.length) {
+          onIdleSpanEnded(spanEndTimestamp);
+          return Reflect.apply(target, thisArg, [spanEndTimestamp, ...rest]);
+        }
+
+        const childEndTimestamps = spans
+          .map(span => spanToJSON(span).timestamp)
+          .filter(timestamp => !!timestamp) as number[];
+        const latestSpanEndTimestamp = childEndTimestamps.length ? Math.max(...childEndTimestamps) : undefined;
+
+        // In reality this should always exist here, but type-wise it may be undefined...
+        const spanStartTimestamp = spanToJSON(span).start_timestamp;
+
+        // The final endTimestamp should:
+        // * Never be before the span start timestamp
+        // * Be the latestSpanEndTimestamp, if there is one, and it is smaller than the passed span end timestamp
+        // * Otherwise be the passed end timestamp
+        // Final timestamp can never be after finalTimeout
+        const endTimestamp = Math.min(
+          spanStartTimestamp ? spanStartTimestamp + finalTimeout / 1000 : Infinity,
+          Math.max(spanStartTimestamp || -Infinity, Math.min(spanEndTimestamp, latestSpanEndTimestamp || Infinity)),
+        );
+
+        onIdleSpanEnded(endTimestamp);
+        return Reflect.apply(target, thisArg, [endTimestamp, ...rest]);
+      },
+    });
+  }
+
   if (!client || !hasTracingEnabled()) {
     const span = new SentryNonRecordingSpan();
 
@@ -118,7 +171,7 @@ export function startIdleSpan(startSpanOptions: StartSpanOptions, options: Parti
       ...getDynamicSamplingContextFromSpan(span),
     } satisfies Partial<DynamicSamplingContext>;
     freezeDscOnSpan(span, dsc);
-
+    patchSpanEnd(span);
     return span;
   }
 
@@ -126,56 +179,7 @@ export function startIdleSpan(startSpanOptions: StartSpanOptions, options: Parti
   const previousActiveSpan = getActiveSpan();
   const span = _startIdleSpan(startSpanOptions);
 
-  // We patch span.end to ensure we can run some things before the span is ended
-  // eslint-disable-next-line @typescript-eslint/unbound-method
-  span.end = new Proxy(span.end, {
-    apply(target, thisArg, args: Parameters<Span['end']>) {
-      if (beforeSpanEnd) {
-        beforeSpanEnd(span);
-      }
-
-      // If the span is non-recording, nothing more to do here...
-      // This is the case if tracing is enabled but this specific span was not sampled
-      if (thisArg instanceof SentryNonRecordingSpan) {
-        return;
-      }
-
-      // Just ensuring that this keeps working, even if we ever have more arguments here
-      const [definedEndTimestamp, ...rest] = args;
-      const timestamp = definedEndTimestamp || timestampInSeconds();
-      const spanEndTimestamp = spanTimeInputToSeconds(timestamp);
-
-      // Ensure we end with the last span timestamp, if possible
-      const spans = getSpanDescendants(span).filter(child => child !== span);
-
-      // If we have no spans, we just end, nothing else to do here
-      if (!spans.length) {
-        onIdleSpanEnded(spanEndTimestamp);
-        return Reflect.apply(target, thisArg, [spanEndTimestamp, ...rest]);
-      }
-
-      const childEndTimestamps = spans
-        .map(span => spanToJSON(span).timestamp)
-        .filter(timestamp => !!timestamp) as number[];
-      const latestSpanEndTimestamp = childEndTimestamps.length ? Math.max(...childEndTimestamps) : undefined;
-
-      // In reality this should always exist here, but type-wise it may be undefined...
-      const spanStartTimestamp = spanToJSON(span).start_timestamp;
-
-      // The final endTimestamp should:
-      // * Never be before the span start timestamp
-      // * Be the latestSpanEndTimestamp, if there is one, and it is smaller than the passed span end timestamp
-      // * Otherwise be the passed end timestamp
-      // Final timestamp can never be after finalTimeout
-      const endTimestamp = Math.min(
-        spanStartTimestamp ? spanStartTimestamp + finalTimeout / 1000 : Infinity,
-        Math.max(spanStartTimestamp || -Infinity, Math.min(spanEndTimestamp, latestSpanEndTimestamp || Infinity)),
-      );
-
-      onIdleSpanEnded(endTimestamp);
-      return Reflect.apply(target, thisArg, [endTimestamp, ...rest]);
-    },
-  });
+  patchSpanEnd(span);
 
   /**
    * Cancels the existing idle timeout, if there is one.

From 373ff2c0be3d9993496a00426747f622efd9d25d Mon Sep 17 00:00:00 2001
From: Francesco Novy <francesco.novy@sentry.io>
Date: Fri, 10 Jan 2025 11:39:09 +0100
Subject: [PATCH 6/7] fix linting

---
 packages/browser/src/tracing/browserTracingIntegration.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/browser/src/tracing/browserTracingIntegration.ts b/packages/browser/src/tracing/browserTracingIntegration.ts
index ebd143bc877d..ab9489b2d314 100644
--- a/packages/browser/src/tracing/browserTracingIntegration.ts
+++ b/packages/browser/src/tracing/browserTracingIntegration.ts
@@ -9,7 +9,7 @@ import {
   startTrackingLongTasks,
   startTrackingWebVitals,
 } from '@sentry-internal/browser-utils';
-import type { Client, IntegrationFn, Span, StartSpanOptions, TransactionSource} from '@sentry/core';
+import type { Client, IntegrationFn, Span, StartSpanOptions, TransactionSource } from '@sentry/core';
 import { dropUndefinedKeys } from '@sentry/core';
 import {
   GLOBAL_OBJ,

From 6bac717f342c2cf4e43fb7c6efd5d83e7751f1e8 Mon Sep 17 00:00:00 2001
From: Francesco Novy <francesco.novy@sentry.io>
Date: Fri, 10 Jan 2025 12:40:40 +0100
Subject: [PATCH 7/7] fix it

---
 packages/browser/src/tracing/browserTracingIntegration.ts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/packages/browser/src/tracing/browserTracingIntegration.ts b/packages/browser/src/tracing/browserTracingIntegration.ts
index ab9489b2d314..2b4af867acc1 100644
--- a/packages/browser/src/tracing/browserTracingIntegration.ts
+++ b/packages/browser/src/tracing/browserTracingIntegration.ts
@@ -458,7 +458,9 @@ export function startBrowserTracingPageLoadSpan(
  * This will only do something if a browser tracing integration has been setup.
  */
 export function startBrowserTracingNavigationSpan(client: Client, spanOptions: StartSpanOptions): Span | undefined {
+  // Reset this to ensure we start a new trace, instead of continuing the last pageload/navigation trace
   getIsolationScope().setPropagationContext({ traceId: generateTraceId() });
+  getCurrentScope().setPropagationContext({ traceId: generateTraceId() });
 
   client.emit('startNavigationSpan', spanOptions);
   getCurrentScope().setTransactionName(spanOptions.name);