adjust getNavigationEntry, undo test "fix"

Author: Lms24

dev-packages/browser-integration-tests/suites/tracing/metrics/web-vitals-ttfb/test.ts

@@ -19,6 +19,7 @@ sentryTest('should capture TTFB vital.', async ({ getLocalTestUrl, page }) => {
   const responseStart = await page.evaluate("performance.getEntriesByType('navigation')[0].responseStart;");
   if (responseStart !== 0) {
     expect(eventData.measurements?.ttfb?.value).toBeDefined();
-    expect(eventData.measurements?.['ttfb.requestTime']?.value).toBeDefined();
   }
+
+  expect(eventData.measurements?.['ttfb.requestTime']?.value).toBeDefined();
 });

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

@@ -415,7 +415,7 @@ export function _addMeasureSpans(
   duration: number,
   timeOrigin: number,
 ): number {
-  const navEntry = getNavigationEntry();
+  const navEntry = getNavigationEntry(false);
   const requestTime = msToSec(navEntry ? navEntry.requestStart : 0);
   // Because performance.measure accepts arbitrary timestamps it can produce
   // spans that happen before the browser even makes a request for the page.
@@ -666,7 +666,7 @@ function setResourceEntrySizeData(
  * ttfb information is added via vendored web vitals library.
  */
 function _addTtfbRequestTimeToMeasurements(_measurements: Measurements): void {
-  const navEntry = getNavigationEntry();
+  const navEntry = getNavigationEntry(false);
   if (!navEntry) {
     return;
   }

packages/browser-utils/src/metrics/web-vitals/lib/getNavigationEntry.ts

@@ -16,18 +16,24 @@
 
 import { WINDOW } from '../../../types';
 
-export const getNavigationEntry = (): PerformanceNavigationTiming | void => {
+// sentry-specific change:
+// add optional param to not check for responseStart (see comment below)
+export const getNavigationEntry = (checkResponseStart = true): PerformanceNavigationTiming | void => {
   const navigationEntry =
     WINDOW.performance && WINDOW.performance.getEntriesByType && WINDOW.performance.getEntriesByType('navigation')[0];
-
   // Check to ensure the `responseStart` property is present and valid.
   // In some cases no value is reported by the browser (for
   // privacy/security reasons), and in other cases (bugs) the value is
   // negative or is larger than the current page time. Ignore these cases:
   // https://github.com/GoogleChrome/web-vitals/issues/137
   // https://github.com/GoogleChrome/web-vitals/issues/162
   // https://github.com/GoogleChrome/web-vitals/issues/275
-  if (navigationEntry && navigationEntry.responseStart > 0 && navigationEntry.responseStart < performance.now()) {
+  if (
+    // sentry-specific change:
+    // We don't want to check for responseStart for our own use of `getNavigationEntry`
+    !checkResponseStart ||
+    (navigationEntry && navigationEntry.responseStart > 0 && navigationEntry.responseStart < performance.now())
+  ) {
     return navigationEntry;
   }
 };