web-vitals
Version:
Easily measure performance metrics in JavaScript
32 lines (31 loc) • 1.88 kB
TypeScript
import { INPAttributionReportOpts, INPMetricWithAttribution } from '../types.js';
/**
* Calculates the [INP](https://web.dev/articles/inp) value for the current
* page and calls the `callback` function once the value is ready, along with
* the `event` performance entries reported for that interaction. The reported
* value is a `DOMHighResTimeStamp`.
*
* A custom `durationThreshold` configuration option can optionally be passed
* to control what `event-timing` entries are considered for INP reporting. The
* default threshold is `40`, which means INP scores of less than 40 will not
* be reported. To avoid reporting no interactions in these cases, the library
* will fall back to the input delay of the first interaction. Note that this
* will not affect your 75th percentile INP value unless that value is also
* less than 40 (well below the recommended
* [good](https://web.dev/articles/inp#what_is_a_good_inp_score) threshold).
*
* If the `reportAllChanges` configuration option is set to `true`, the
* `callback` function will be called as soon as the value is initially
* determined as well as any time the value changes throughout the page
* lifespan.
*
* _**Important:** INP should be continually monitored for changes throughout
* the entire lifespan of a page—including if the user returns to the page after
* it has been hidden/backgrounded. However, since browsers often [will not fire
* additional callbacks once the user has backgrounded a
* page](https://developer.chrome.com/blog/page-lifecycle-api/#advice-hidden),
* `callback` is always called when the page's visibility state changes to
* hidden. As a result, the `callback` function might be called multiple times
* during the same page load._
*/
export declare const onINP: (onReport: (metric: INPMetricWithAttribution) => void, opts?: INPAttributionReportOpts) => void;