This commit implements the main proposal presented in
https://github.com/vercel/next.js/issues/39241
to add attribution to web vitals.
Attribution adds more specific debugging info to web vitals,
for example in the case of Cumulative Layout Shift (CLS),
we might want to know
> What's the first element that shifted when the single largest layout shift occurred?
on in the case of Largest Contentful Paint (LCP),
> What's the element corresponding to the LCP for the page?
> If it is an image, what's the URL of the image resource?
Attribution is *disabled* by default because it could potentially
generate a lot data and overwhelm the RUM backend.
It is enabled *per metric* (LCP, FCP, CLS, etc)
As part of this change, `web-vitals` has been upgraded to v3.0.0
This version contains minor bug fixes, please see changelog at
9fe3cc02c8Fixes#39241
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
## Feature
- [x] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
- [x] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [ ] Make sure the linting passes by running `pnpm lint`
- [x] The examples guidelines are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing.md#adding-examples)
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>
Sends web vitals to Vercel analytics.
My plan for the test was to assert the data sent by the client but there's a bug where it's always null when sending a blob https://github.com/microsoft/playwright/issues/6479.
When adding support for a custom web vitals reporter it will be easier to assert the values sent by the reporter.
This commit lets users measure their Interaction to Next Paint [INP](https://web.dev/inp/) web vital.
Note that the `web-vitals` package is beta to denote that INP is an experimental metric, the code is stable and v3 is backwards compatible.
`web-vitals` CHANGELOG for v3:
- [BREAKING] Report TTFB after a bfcache restore
- [BREAKING] Only include last LCP entry in metric entries
- Add support for the new INP metric
- Rename getXXX() functions to onXXX()
- Add a navigationType property to the Metric object
See https://github.com/GoogleChrome/web-vitals/blob/next/CHANGELOG.md
Upgraded `playwright-chromium` from `1.14.1` to `1.17.2` because the Events Timing API used to measure INP is only available in Chromium >= v98.
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [ ] Make sure the linting passes by running `yarn lint`
### Experimental
Introduce `next/vitals` and `useExperimentalWebVitalsReport` API which is not limited by `_app`.
`pages/index.js`
```jsx
import { useExperimentalWebVitalsReport } from 'next/vitals'
export default function Index() {
useExperimentalWebVitalsReport((metric) => {
// handle metric...
})
return 'sup'
}
```
Send can result in `false` when it did not send the result so we have to fall back in that case. Shared by @timer after my PR was landed.
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [ ] Make sure the linting passes
Also ensures that even if the navigator.sendBeacon fails the fetch fallback is used.
Fixes#23856. This is likely, as no reproduction was provided it was not possible to verify if it actually fixes the issue.
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
## Documentation / Examples
- [ ] Make sure the linting passes
This adds ncc inlining optimizations for the following dependencies:
* cacache
* schema-utils
* find-cache-dir
* mkdirp
* neo-async
* web-vitals
The slight increase in output in the reports here is due to the variation of the bundled version of web-vitals.
In addition, this moves ast-types to be a devDependencies entry instead of in dependencies as it was before https://github.com/vercel/next.js/pull/14746 as I could not see any production usage (ping @prateekbh). Happy to separate that out into a separate PR if preferred too.
This PR adjust the Web Vitals reporting to be called *after* rendering occurs. It used to work like this, but React's render method is no longer synchronous—so we have to do it in an effect.
Existing tests should cover this code path, and IMO it's unfeasible to test that it's invoked _after_ hydration.
Also removed the `&& ST` condition which is not relevant to Web Vitals.
