JS errors not appearing in Sentry dashboard

[mmmoussa]

What React Native libraries do you use?

React Navigation, Hermes

Are you using sentry.io or on-premise?

sentry.io (SaS)

@sentry/react-native SDK Version

6.1.0

How does your development environment look like?

System:
OS: macOS 14.1.2
CPU: (10) arm64 Apple M1 Pro
Memory: 109.95 MB / 32.00 GB
Shell:
version: "5.9"
path: /bin/zsh
Binaries:
Node:
version: 20.10.0
path: ~/.n/bin/node
Yarn:
version: 3.6.4
path: ~/.yarn/bin/yarn
npm:
version: 10.2.3
path: ~/.n/bin/npm
Watchman: Not Found
Managers:
CocoaPods:
version: 1.15.2
path: /opt/homebrew/bin/pod
SDKs:
iOS SDK:
Platforms:
- DriverKit 23.0
- iOS 17.0
- macOS 14.0
- tvOS 17.0
- watchOS 10.0
Android SDK:
API Levels:
- "28"
- "30"
- "31"
- "32"
- "33"
- "34"
Build Tools:
- 30.0.2
- 30.0.3
- 31.0.0
- 32.0.0
- 32.1.0
- 33.0.0
- 33.0.0
- 33.0.1
- 34.0.0
- 35.0.0
System Images:
- android-26 | Google APIs ARM 64 v8a
- android-28 | ARM 64 v8a
- android-28 | Google APIs ARM 64 v8a
- android-28 | Google ARM64-V8a Play ARM 64 v8a
- android-29 | Google APIs ARM 64 v8a
- android-30 | Google APIs ARM 64 v8a
- android-31 | ARM 64 v8a
- android-31 | Google APIs ARM 64 v8a
- android-31 | Google Play ARM 64 v8a
- android-32 | Google APIs ARM 64 v8a
- android-32 | Google Play ARM 64 v8a
- android-33 | Google APIs ARM 64 v8a
- android-33 | Google Play ARM 64 v8a
- android-34 | Google Play ARM 64 v8a
Android NDK: 27.0.11902837-beta2
IDEs:
Android Studio: 2023.2 AI-232.10300.40.2321.11567975
Xcode:
version: 15.0.1/15A507
path: /usr/bin/xcodebuild
Languages:
Java:
version: 17.0.9
path: /usr/bin/javac
Ruby:
version: 3.3.5
path: /Users/mmmoussa/.rbenv/shims/ruby
npmPackages:
"@react-native-community/cli":
installed: 15.0.0
wanted: latest
react:
installed: 18.3.1
wanted: 18.3.1
react-native:
installed: 0.75.4
wanted: 0.75.4
react-native-macos: Not Found
npmGlobalPackages:
"react-native": Not Found
Android:
hermesEnabled: true
newArchEnabled: false
iOS:
hermesEnabled: true
newArchEnabled: false

Sentry.init()

Sentry.init({
  dsn: SENTRY_DSN,
  debug: true,
  enabled: true,
})

Steps to Reproduce

1. Build Android or iOS build as either debug or release build
2. Add the following buttons to a screen in the app:

<Button title="Test JS Crash" onPress={() => {throw new Error('Test Sentry JS Crash Capturing')}} />
<Button title="Test Sentry captureException" onPress={() => {Sentry.captureException(new Error('Test Sentry captureException'))}} />
<Button title="Test Sentry native crash" onPress={() => {Sentry.nativeCrash()}} />

3. Try pressing each of the buttons

Expected Result

All three buttons should lead to issues appearing in Sentry.

Actual Result

Only the third button (native crash) is reported in the Sentry dashboard, the other two are not.

For additional context:

• We have been using Sentry for years, and this seems to have only become an issue within the last few months though we're having trouble pinpointing exactly when it started
• Recently we increased our sampling rate from 1% to 100%. We observed an issue that seems related to this report through the Stats page of the Sentry dashboard. With 1% sampling rate we used to have most events being discarded as client discards under the sampling rate reason, and then a small amount being dropped due to network error and cache overflow. Now at 100% sampling rate, we see a similar amount of client discards, but they're all due to the other reasons, primarily being network error, cache overflow, event processor, and queue overflow. Only around 1% of errors are being accepted.
• With our latest production releases, we do see a couple js errors reported for those releases, but they are incredibly rare compared with the native errors and with the prevalence we know they should have

[mmmoussa]

We managed to track down the cause of this issue. This is the offending commit: getsentry/sentry-javascript@e128936#diff-f1d46a8517e17eef8c9e3dbb4dfc1524034371b35e5cbbbcae3bd6c560a62ae0R38. We are using https://github.com/mateioprea/react-native-random-values-jsi-helper to provide an implementation of Crypto.getRandomValues() however it is not meeting the spec because it does not overwrite the elements of the input array, which is necessary to accommodate the change made to Sentry's uuid4 function. As a result, all js events were being sent with the id 10000000100040008000100000000000 instead of a valid UUID.

While technically the bug here is not from the Sentry SDK, I would consider there to be several other issues with Sentry's system as a whole that this experience has uncovered:

1. Error events sent with an invalid event id are still receiving a 200 response and are not reported in the sdk as having been discarded.
2. Events with duplicate ids are likely being classified under "network error" as the discard reason even though that's not the case.
3. Sentry provides no insight into the handling and observability of duplicate event ids