import { Metrics, PerformanceMetricsItemQueryResponse } from 'calypso/data/site-profiler/types'; import { Valuation } from '../types/performance-metrics'; export const getMetricsNames = ( translate: ( text: string ) => string ) => ( { fcp: { name: translate( 'First Contentful Paint' ) }, lcp: { name: translate( 'Largest Contentful Paint' ) }, cls: { name: translate( 'Cumulative Layout Shift' ) }, inp: { name: translate( 'Interaction to Next Paint' ) }, ttfb: { name: translate( 'Time to First Byte' ) }, tbt: { name: translate( 'Total Blocking Time' ) }, overall: { name: translate( 'Performance Score' ) }, } ); export const getMetricValuations = ( translate: ( text: string ) => string ) => ( { fcp: { good: translate( 'Your site‘s First Contentful Paint is excellent' ), needsImprovement: translate( 'Your site‘s First Contentful Paint needs improvement' ), bad: translate( 'Your site‘s First Contentful Paint is poor' ), heading: translate( 'What is First Contentful Paint?' ), aka: translate( '(FCP)' ), explanation: translate( 'First Contentful Paint reflects the time it takes to display the first text or image to visitors. The best sites load in under 1.8 seconds.' ), docsUrl: 'https://developer.wordpress.com/docs/site-performance/speed-test/#first-contentful-paint-fcp-', }, lcp: { good: translate( 'Your site‘s Largest Contentful Paint is excellent' ), needsImprovement: translate( 'Your site‘s Largest Contentful Paint needs improvement' ), bad: translate( 'Your site‘s Largest Contentful Paint is poor' ), heading: translate( 'What is Largest Contentful Paint?' ), aka: translate( '(LCP)' ), explanation: translate( 'Largest Contentful Paint measures the time it takes for the largest visible element (like an image or text block) on a page to load. The best sites load in under 2.5 seconds.' ), docsUrl: 'https://developer.wordpress.com/docs/site-performance/speed-test/#largest-contentful-paint-lcp-', }, cls: { good: translate( 'Your site‘s Cumulative Layout Shift is excellent' ), needsImprovement: translate( 'Your site‘s Cumulative Layout Shift needs improvement' ), bad: translate( 'Your site‘s Cumulative Layout Shift is poor' ), heading: translate( 'What is Cumulative Layout Shift?' ), aka: translate( '(CLS)' ), explanation: translate( 'Cumulative Layout Shift is assessed by measuring how often content moves unexpectedly during loading. The best sites have a score of 0.1 or lower.' ), docsUrl: 'https://developer.wordpress.com/docs/site-performance/speed-test/#cumulative-layout-shift-cls-', }, inp: { good: translate( 'Your site‘s Interaction to Next Paint is excellent' ), needsImprovement: translate( 'Your site‘s Interaction to Next Paint needs improvement' ), bad: translate( 'Your site‘s Interaction to Next Paint is poor' ), heading: translate( 'What is Interaction to Next Paint?' ), aka: translate( '(INP)' ), explanation: translate( 'Interaction to Next Paint measures the overall responsiveness of a webpage by evaluating how quickly it reacts to user interactions. A good score is 200 milliseconds or less, indicating that the page responds swiftly to user inputs.' ), docsUrl: 'https://developer.wordpress.com/docs/site-performance/speed-test/#interaction-to-next-paint-inp-', }, ttfb: { good: translate( 'Your site‘s Time to First Byte is excellent' ), needsImprovement: translate( 'Your site‘s Time to First Byte needs improvement' ), bad: translate( 'Your site‘s Time to First Byte is poor' ), heading: translate( 'What is Time to First Byte?' ), aka: translate( '(TTFB)' ), explanation: translate( 'Time to First Byte reflects the time taken for a user‘s browser to receive the first byte of data from the server after making a request. The best sites load around 800 milliseconds or less.' ), docsUrl: 'https://developer.wordpress.com/docs/site-performance/speed-test/#time-to-first-byte-ttfb-', }, tbt: { good: translate( 'Your site‘s Total Blocking Time is excellent' ), needsImprovement: translate( 'Your site‘s Total Blocking Time needs improvement' ), bad: translate( 'Your site‘s Total Blocking Time is poor' ), heading: translate( 'What is Total Blocking Time?' ), aka: translate( '(TBT)' ), explanation: translate( 'Total Blocking Time measures the total amount of time that a page is blocked from responding to user input, such as mouse clicks, screen taps, or keyboard presses. The best sites have a wait time of less than 200 milliseconds.' ), docsUrl: 'https://developer.wordpress.com/docs/site-performance/speed-test/#total-blocking-time-tbt-', }, overall: { good: translate( 'Your site‘s Performance Score is excellent' ), needsImprovement: translate( 'Your site‘s Performance Score needs improvement' ), bad: translate( 'Your site‘s Performance Score is poor' ), heading: translate( 'What is Performance Score?' ), aka: translate( '(PS)' ), explanation: translate( 'The performance score is a combined representation of your site‘s individual speed metrics.' ), docsUrl: 'https://developer.wordpress.com/docs/site-performance/speed-test/#performance-score', }, } ); // bad values are only needed as a maximum value on the scales export const metricsThresholds = { lcp: { good: 2500, needsImprovement: 4000, bad: 6000, }, cls: { good: 0.1, needsImprovement: 0.25, bad: 0.4, }, fcp: { good: 1800, needsImprovement: 3000, bad: 5000, }, ttfb: { good: 800, needsImprovement: 1800, bad: 3000, }, inp: { good: 200, needsImprovement: 500, bad: 1000, }, tbt: { good: 200, needsImprovement: 600, bad: 1000, }, overall: { good: 100, needsImprovement: 89, bad: 49, }, }; export const getPerformanceStatus = ( value: number ) => { if ( value <= 49 ) { return 'bad'; } else if ( value > 49 && value < 90 ) { return 'needsImprovement'; } return 'good'; }; export const mapThresholdsToStatus = ( metric: Metrics, value: number ): Valuation => { const { good, needsImprovement } = metricsThresholds[ metric ]; if ( metric === 'overall' ) { return getPerformanceStatus( value ); } if ( value <= good ) { return 'good'; } if ( value <= needsImprovement ) { return 'needsImprovement'; } return 'bad'; }; export const max2Decimals = ( val: number ) => +Number( val ).toFixed( 2 ); export const displayValue = ( metric: Metrics, value: number ): string => { if ( value === null || value === undefined ) { return ''; } if ( [ 'lcp', 'fcp', 'ttfb', 'inp', 'fid', 'tbt' ].includes( metric ) ) { return `${ max2Decimals( value / 1000 ) }s`; } return `${ max2Decimals( value ) }`; }; export const filterRecommendations = ( selectedFilter: string, audit?: PerformanceMetricsItemQueryResponse ) => { return ( selectedFilter === 'all' || audit?.metricSavings?.hasOwnProperty( selectedFilter.toUpperCase() ) ); }; export const highImpactAudits = [ 'render-blocking-resources', 'uses-responsive-images', 'uses-optimized-images', 'offscreen-images', 'server-response-time', 'mainthread-work-breakdown', 'largest-contentful-paint-element', ];