20 lines
1.1 KiB
TypeScript
20 lines
1.1 KiB
TypeScript
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import { MetricRatingThresholds, ReportOpts, TTFBMetric } from './types.js';
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/** Thresholds for TTFB. See https://web.dev/articles/ttfb#what_is_a_good_ttfb_score */
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export declare const TTFBThresholds: MetricRatingThresholds;
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/**
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* Calculates the [TTFB](https://web.dev/articles/ttfb) value for the
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* current page and calls the `callback` function once the page has loaded,
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* along with the relevant `navigation` performance entry used to determine the
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* value. The reported value is a `DOMHighResTimeStamp`.
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*
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* Note, this function waits until after the page is loaded to call `callback`
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* in order to ensure all properties of the `navigation` entry are populated.
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* This is useful if you want to report on other metrics exposed by the
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* [Navigation Timing API](https://w3c.github.io/navigation-timing/). For
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* example, the TTFB metric starts from the page's [time
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* origin](https://www.w3.org/TR/hr-time-2/#sec-time-origin), which means it
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* includes time spent on DNS lookup, connection negotiation, network latency,
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* and server processing time.
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*/
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export declare const onTTFB: (onReport: (metric: TTFBMetric) => void, opts?: ReportOpts) => void;
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