Expo Router integration improvement: Prefetch route performance measurement with automatically created spans #5606

alwx · 2026-02-02T11:00:25Z

📢 Type of change

Bugfix
New feature
Enhancement
Refactoring

📜 Description

Fixes #5423
What happens here is we create spans automatically if enablePrefetchTracking is set to true for the reactNavigationIntegration OR if the ExpoRouter is wrapped with Sentry.wrapExpoRouter() — it's done this way because there are two ways of using prefetch with ExpoRouter.

💚 How did you test it?

CI, manually

📝 Checklist

I added tests to verify changes
No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled
I updated the docs if needed.
I updated the wizard if needed.
All tests passing
No breaking changes

🔮 Next steps

…automatically created spans

github-actions · 2026-02-02T11:00:45Z

Semver Impact of This PR

⚪ None (no version bump detected)

📋 Changelog Preview

This is how your changes will appear in the changelog.
Entries from this PR are highlighted with a left border (blockquote style).

Expo Router integration improvement: Prefetch route performance measurement with automatically created spans by alwx in #5606

chore(deps): update Bundler Plugins to v4.9.0 by github-actions in #5608
e2e tests on Cirrus Labs runners by alwx in #5485
chore(deps): bump getsentry/craft from 2.20.0 to 2.20.1 by dependabot in #5603
chore(deps): bump getsentry/craft/.github/workflows/changelog-preview.yml from 2.20.0 to 2.20.1 by dependabot in #5604
chore(deps): bump github/codeql-action from 4.31.11 to 4.32.0 by dependabot in #5605
Ref: Add Claude task by lucas-zimerman in #5602
chore(deps): update JavaScript SDK to v10.38.0 by github-actions in #5596

_{🤖 This preview updates automatically when you update the PR.}

github-actions · 2026-02-02T13:40:47Z

Android (legacy) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	411.18 ms	432.30 ms	21.12 ms
Size	43.75 MiB	48.41 MiB	4.66 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`f3b058c`+dirty	501.18 ms	536.70 ms	35.52 ms
`bfe454a`+dirty	573.44 ms	579.46 ms	6.02 ms
`294387d`+dirty	424.30 ms	465.40 ms	41.10 ms
`955f2eb`+dirty	422.74 ms	410.19 ms	-12.55 ms
`3bd3f0d`+dirty	447.21 ms	472.31 ms	25.10 ms
`d081295`+dirty	408.08 ms	453.62 ms	45.54 ms
`ad27f6e`+dirty	471.44 ms	516.23 ms	44.79 ms
`07808fb`+dirty	419.10 ms	419.08 ms	-0.02 ms
`170d5ea`+dirty	407.92 ms	422.49 ms	14.57 ms
`8e653ac`+dirty	360.28 ms	372.04 ms	11.76 ms

App size

Revision	Plain	With Sentry	Diff
`f3b058c`+dirty	43.75 MiB	48.07 MiB	4.32 MiB
`bfe454a`+dirty	17.75 MiB	19.69 MiB	1.94 MiB
`294387d`+dirty	43.75 MiB	48.04 MiB	4.29 MiB
`955f2eb`+dirty	17.75 MiB	19.70 MiB	1.95 MiB
`3bd3f0d`+dirty	17.75 MiB	19.70 MiB	1.95 MiB
`d081295`+dirty	43.75 MiB	48.04 MiB	4.29 MiB
`ad27f6e`+dirty	43.75 MiB	48.07 MiB	4.32 MiB
`07808fb`+dirty	17.75 MiB	19.70 MiB	1.95 MiB
`170d5ea`+dirty	17.75 MiB	19.70 MiB	1.95 MiB
`8e653ac`+dirty	17.75 MiB	19.75 MiB	2.00 MiB

github-actions · 2026-02-02T13:46:18Z

iOS (legacy) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1214.91 ms	1219.30 ms	4.39 ms
Size	3.38 MiB	4.60 MiB	1.22 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`6bd9054`+dirty	1212.20 ms	1217.89 ms	5.70 ms
`d73150f`+dirty	1198.44 ms	1210.06 ms	11.62 ms
`d081295`+dirty	1214.40 ms	1211.27 ms	-3.13 ms
`d1fd647`+dirty	1219.35 ms	1233.18 ms	13.83 ms
`ea3e26e`+dirty	1229.13 ms	1228.46 ms	-0.67 ms
`80e4616`+dirty	1221.32 ms	1225.64 ms	4.32 ms
`955f2eb`+dirty	1235.06 ms	1253.88 ms	18.81 ms
`5ee3314`+dirty	1215.18 ms	1207.64 ms	-7.54 ms
`70250df`+dirty	1214.51 ms	1215.04 ms	0.53 ms
`664c66f`+dirty	1215.37 ms	1221.30 ms	5.92 ms

App size

Revision	Plain	With Sentry	Diff
`6bd9054`+dirty	3.41 MiB	4.67 MiB	1.25 MiB
`d73150f`+dirty	3.38 MiB	4.60 MiB	1.22 MiB
`d081295`+dirty	3.41 MiB	4.59 MiB	1.18 MiB
`d1fd647`+dirty	2.63 MiB	3.99 MiB	1.36 MiB
`ea3e26e`+dirty	3.41 MiB	4.58 MiB	1.17 MiB
`80e4616`+dirty	3.38 MiB	4.60 MiB	1.22 MiB
`955f2eb`+dirty	2.63 MiB	3.98 MiB	1.35 MiB
`5ee3314`+dirty	2.63 MiB	3.99 MiB	1.35 MiB
`70250df`+dirty	3.44 MiB	4.59 MiB	1.15 MiB
`664c66f`+dirty	3.38 MiB	4.60 MiB	1.22 MiB

github-actions · 2026-02-02T14:01:30Z

Android (new) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	399.10 ms	433.08 ms	33.98 ms
Size	43.94 MiB	49.27 MiB	5.33 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`f3b058c`+dirty	422.90 ms	468.30 ms	45.40 ms
`294387d`+dirty	359.44 ms	393.40 ms	33.97 ms
`1d62dde`+dirty	366.59 ms	408.80 ms	42.21 ms
`d081295`+dirty	416.95 ms	461.24 ms	44.29 ms
`ad27f6e`+dirty	484.67 ms	532.79 ms	48.12 ms
`1226664`+dirty	377.65 ms	453.94 ms	76.29 ms
`083f560`+dirty	383.96 ms	417.76 ms	33.80 ms
`ec14be7`+dirty	401.58 ms	475.26 ms	73.68 ms
`eb07ba3`+dirty	419.49 ms	482.12 ms	62.63 ms
`d1fd647`+dirty	374.46 ms	409.51 ms	35.05 ms

App size

Revision	Plain	With Sentry	Diff
`f3b058c`+dirty	43.94 MiB	48.90 MiB	4.96 MiB
`294387d`+dirty	43.94 MiB	48.87 MiB	4.93 MiB
`1d62dde`+dirty	7.15 MiB	8.46 MiB	1.31 MiB
`d081295`+dirty	43.94 MiB	48.87 MiB	4.93 MiB
`ad27f6e`+dirty	43.94 MiB	48.90 MiB	4.96 MiB
`1226664`+dirty	7.15 MiB	8.46 MiB	1.30 MiB
`083f560`+dirty	7.15 MiB	8.43 MiB	1.28 MiB
`ec14be7`+dirty	7.15 MiB	8.42 MiB	1.26 MiB
`eb07ba3`+dirty	7.15 MiB	8.42 MiB	1.27 MiB
`d1fd647`+dirty	7.15 MiB	8.43 MiB	1.28 MiB

antonis · 2026-02-02T16:09:36Z

@sentry review

packages/core/test/tracing/expoRouter.test.ts

packages/core/src/js/tracing/expoRouter.ts

github-actions · 2026-02-02T16:26:59Z

iOS (new) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1212.58 ms	1206.69 ms	-5.89 ms
Size	3.38 MiB	4.60 MiB	1.22 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`6bd9054`+dirty	1207.02 ms	1199.27 ms	-7.76 ms
`d73150f`+dirty	1224.52 ms	1227.17 ms	2.65 ms
`d081295`+dirty	1205.24 ms	1207.52 ms	2.28 ms
`d1fd647`+dirty	1218.16 ms	1225.82 ms	7.65 ms
`ea3e26e`+dirty	1216.61 ms	1214.15 ms	-2.47 ms
`80e4616`+dirty	1206.90 ms	1205.94 ms	-0.96 ms
`955f2eb`+dirty	1225.78 ms	1239.27 ms	13.49 ms
`5ee3314`+dirty	1234.25 ms	1235.44 ms	1.19 ms
`70250df`+dirty	1211.96 ms	1222.31 ms	10.35 ms
`664c66f`+dirty	1195.94 ms	1194.80 ms	-1.14 ms

App size

Revision	Plain	With Sentry	Diff
`6bd9054`+dirty	3.41 MiB	4.67 MiB	1.25 MiB
`d73150f`+dirty	3.38 MiB	4.60 MiB	1.22 MiB
`d081295`+dirty	3.41 MiB	4.59 MiB	1.18 MiB
`d1fd647`+dirty	3.19 MiB	4.56 MiB	1.37 MiB
`ea3e26e`+dirty	3.41 MiB	4.58 MiB	1.17 MiB
`80e4616`+dirty	3.38 MiB	4.60 MiB	1.22 MiB
`955f2eb`+dirty	3.19 MiB	4.55 MiB	1.36 MiB
`5ee3314`+dirty	3.19 MiB	4.55 MiB	1.37 MiB
`70250df`+dirty	3.44 MiB	4.59 MiB	1.15 MiB
`664c66f`+dirty	3.38 MiB	4.60 MiB	1.22 MiB

packages/core/src/js/tracing/expoRouter.ts

alwx · 2026-02-03T11:11:07Z

StartSpanOptions doesn't actually have an origin attribute but SpanAttributes has sentry.origin which is what I added and also added those to tests.
@antonis it's ready for a second look.

packages/core/src/js/tracing/reactnavigation.ts

antonis · 2026-02-03T11:23:50Z

samples/expo/app/(tabs)/index.tsx

  const { currentlyRunning } = useUpdates();
+  const rawRouter = useRouter();
+  // Wrap the router to monitor prefetch performance
+  const router = Sentry.wrapExpoRouter(rawRouter);


I'm getting an error

✖ sentry-react-native-expo-sample:fix /Users/antonis/git/sentry-react-native/samples/expo/app/(tabs)/index.tsx 18:25 error 'wrapExpoRouter' not found in imported namespace 'Sentry' import/namespace ✖ 1 problem (1 error, 0 warnings)

lucas-zimerman

The PR is looking good! thank you.!
A minor note: should we also mention this on sentry docs?

antonis

LGTM 🚀
Let's wait for the tests to get 🟢 and merge

A minor note: should we also mention this on sentry docs?

Makes sense 👍

alwx · 2026-02-03T14:01:44Z

@antonis @lucas-zimerman will do the docs change later today, no worries

Expo Router improvement: Prefetch route performance measurement with …

3bb6c56

…automatically created spans

alwx changed the title ~~WIP: Expo Router improvement: Prefetch route performance measurement with automatically created spans~~ WIP: Expo Router integration improvement: Prefetch route performance measurement with automatically created spans Feb 2, 2026

alwx added 3 commits February 2, 2026 13:59

Performance measurement for manual expo router prefetch() call

3aeecae

Changelog entry with the usage example

9999084

Fix

a2f6042

alwx changed the title ~~WIP: Expo Router integration improvement: Prefetch route performance measurement with automatically created spans~~ Expo Router integration improvement: Prefetch route performance measurement with automatically created spans Feb 2, 2026

alwx added the ready-to-merge Triggers the full CI test suite label Feb 2, 2026

alwx self-assigned this Feb 2, 2026

alwx marked this pull request as ready for review February 2, 2026 13:21

alwx requested review from antonis and lucas-zimerman as code owners February 2, 2026 13:21

Merge branch 'main' into alwx/feature/prefetch-tracking

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antonis reviewed Feb 2, 2026

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alwx added 3 commits February 3, 2026 12:00

sentry.origin added, tests adjusted

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File renamed

8fd95b7

Test fixes

534c62c

Merge branch 'main' into alwx/feature/prefetch-tracking

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Lint fix

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lucas-zimerman approved these changes Feb 3, 2026

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alwx merged commit 42a723e into main Feb 3, 2026
98 of 99 checks passed

alwx deleted the alwx/feature/prefetch-tracking branch February 3, 2026 14:01

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Expo Router integration improvement: Prefetch route performance measurement with automatically created spans #5606

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📝 Checklist

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Baseline results on branch: main

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App size

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Baseline results on branch: main

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App size

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Baseline results on branch: main

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