[Tracks] Annotate rnPerfIssue for Cascading Updates in DEV #34961
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Summary: Introduces the concept of **Performance Issues**, an experimental performance signals concept for React Native. **Design** Performance Issues are an **experimental** user space API via the User Timings [`devtools` object](https://developer.chrome.com/docs/devtools/performance/extension#devtools_object). ``` performance.measure({ start, end, detail: { devtools: { ... rnIssueLevel: 'info' | 'warning' | 'error' } } }); ``` When `rnIssueLevel` is present, we eagerly report an the event over CDP, regardless of an active performance trace, via the `"__react_native_perf_issues_reporter"` runtime binding. **This diff** - Adds a `perfIssuesEnabled` feature flag. - Initial implementation of the above API. - Initially reports a "Cascading Render" issue, aligning 1:1 with the corresponding React performance track event (note: to be added in the React codebase, see facebook/react#34961). This feature is gated by the `perfMonitorV2Enabled` feature flag. Changelog: [Internal] Differential Revision: D85448200
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| name: 'React: Cascading Update', | ||
| severity: 'warning', | ||
| description: | ||
| 'A cascading update is a update that is triggered by a previous update. This can lead to performance issues and should be avoided.', |
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@hoxyq Let me know what you think about this description and if we can improve it (as you wrote the docs!)
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Summary:
Introduces the concept of **Performance Issues**, an experimental performance signals concept for React Native.
**Design**
Performance Issues are an **experimental** user space API via the User Timings `detail` object.
```
performance.measure({
start,
end,
detail: {
devtools: {
...
},
rnPerfIssue: {
name: 'React: Cascading Update',
severity: 'warning', // 'info' | 'warning' | 'error',
description:
'A cascading update is a update that is triggered by a previous update. This can lead to performance issues and should be avoided.',
learnMoreUrl:
'https://react.dev/reference/dev-tools/react-performance-tracks#cascading-updates',
}
}
});
```
When `rnPerfIssue` is present, we eagerly report an the event over CDP, regardless of an active performance trace, via the `"__react_native_perf_issues_reporter"` runtime binding.
**This diff**
- Adds a `perfIssuesEnabled` feature flag.
- Initial implementation of the above API.
- Initially reports a "Cascading Render" issue, aligning 1:1 with the corresponding React performance track event (note: to be added in the React codebase, see facebook/react#34961).
This feature is gated by the `perfMonitorV2Enabled` feature flag.
Changelog: [Internal]
Differential Revision: D85448200
huntie
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Oct 28, 2025
…ate payload structure for Performance Issues (facebook#54265) Summary: Pull Request resolved: facebook#54265 Introduces the concept of **Performance Issues**, an experimental performance signals concept for React Native. **Design** Performance Issues are an **experimental** user space API via the User Timings `detail` object. ``` performance.measure({ start, end, detail: { devtools: { ... }, rnPerfIssue: { name: 'React: Cascading Update', severity: 'warning', // 'info' | 'warning' | 'error', description: 'A cascading update is a update that is triggered by a previous update. This can lead to performance issues and should be avoided.', learnMoreUrl: 'https://react.dev/reference/dev-tools/react-performance-tracks#cascading-updates', } } }); ``` When `rnPerfIssue` is present, we eagerly report an the event over CDP, regardless of an active performance trace, via the `"__react_native_perf_issues_reporter"` runtime binding. **This diff** - Adds a `perfIssuesEnabled` feature flag. - Initial implementation of the above API. - Initially reports a "Cascading Render" issue, aligning 1:1 with the corresponding React performance track event (note: to be added in the React codebase, see facebook/react#34961). This feature is gated by the `perfMonitorV2Enabled` feature flag. Changelog: [Internal] Differential Revision: D85448200
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Summary
Updates
ReactFiberPerformanceTrack.jsto report a React Native Performance Issue (rnPerfIssue, see facebook/react-native#54265) when emitting a Cascading Update trace event when__DEV__is set.How did you test this change?
Tested end to end with the experiment in React Native. [Meta only]: See test plan of D85448199.