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Collapse the five web-vitals trackers into a shared helper #120

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Collapse the five web-vitals trackers into a shared helper #120

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154 changes: 73 additions & 81 deletions src/javascript/log.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@ import {onCLS, onFCP, onINP, onLCP, onTTFB} from 'web-vitals/attribution';
import {Logger} from './Logger.ts';
import {uuid} from './utils/uuid.ts';

import type {MetricWithAttribution, ReportOpts} from 'web-vitals/attribution';
import type {Params} from './Logger.ts';

/**
Expand Down Expand Up @@ -145,99 +146,90 @@ const trackUnhandledErrors = () => {
removeEventListener('unhandledrejection', self.__e);
};

const trackCLS = async () => {
onCLS(
(metric) => {
log.event(metric.name, {
value: metric.delta,
metric_rating: metric.rating,
metric_value: metric.value,
debug_target: metric.attribution.largestShiftTarget
? metric.attribution.largestShiftTarget
: '(not set)',
event_id: metric.id,
});
},
{reportAllChanges: true},
);
/**
* Registers a web-vitals metric handler that logs an event with the common
* metric params plus any metric-specific params returned by
* `getAttributionParams`.
*/
const trackMetric = <T extends MetricWithAttribution, O extends ReportOpts>(
onFn: (onReport: (metric: T) => void, opts?: O) => void,
opts: O,
getAttributionParams: (metric: T) => Params,
) => {
onFn((metric) => {
log.event(metric.name, {
value: metric.delta,
metric_rating: metric.rating,
metric_value: metric.value,
...getAttributionParams(metric),
event_id: metric.id,
});
}, opts);
};

const trackFCP = async () => {
onFCP(
(metric) => {
log.event(metric.name, {
value: metric.delta,
metric_rating: metric.rating,
metric_value: metric.value,
original_page_path: originalPathname,
debug_ttfb: metric.attribution.timeToFirstByte,
debug_fb2fcp: metric.attribution.firstByteToFCP,
event_id: metric.id,
});
},
{reportAllChanges: true},
);
const trackCLS = () => {
trackMetric(onCLS, {reportAllChanges: true}, (metric) => ({
debug_target: metric.attribution.largestShiftTarget
? metric.attribution.largestShiftTarget
: '(not set)',
}));
};

const trackINP = async () => {
onINP(
(metric) => {
log.event(metric.name, {
value: metric.delta,
metric_rating: metric.rating,
metric_value: metric.value,
debug_target: metric.attribution.interactionTarget || '(not set)',
debug_type: metric.attribution.interactionType,
debug_time: metric.attribution.interactionTime,
debug_delay: metric.attribution.inputDelay,
debug_processing: metric.attribution.processingDuration,
debug_presentation: metric.attribution.presentationDelay,
event_id: metric.id,
});
},
const trackFCP = () => {
trackMetric(onFCP, {reportAllChanges: true}, (metric) => ({
original_page_path: originalPathname,
debug_ttfb: metric.attribution.timeToFirstByte,
debug_fb2fcp: metric.attribution.firstByteToFCP,
}));
};

const trackINP = () => {
trackMetric(
onINP,
{durationThreshold: 16, reportAllChanges: true},
(metric) => ({
debug_target: metric.attribution.interactionTarget || '(not set)',
debug_type: metric.attribution.interactionType,
debug_time: metric.attribution.interactionTime,
debug_delay: metric.attribution.inputDelay,
debug_processing: metric.attribution.processingDuration,
debug_presentation: metric.attribution.presentationDelay,
}),
);
};

const trackLCP = async () => {
onLCP(
(metric) => {
let dynamicFetchPriority: string | undefined;
const trackLCP = () => {
trackMetric(onLCP, {reportAllChanges: true}, (metric) => {
let dynamicFetchPriority: string | undefined;

// If the LCP element is an image, send a hint for the next visitor.
const {target, lcpEntry} = metric.attribution;
// If the LCP element is an image, send a hint for the next visitor.
const {target, lcpEntry} = metric.attribution;

if (lcpEntry?.url && lcpEntry.element?.tagName.toLowerCase() === 'img') {
const elementWithPriority = document.querySelector('[fetchpriority]');
if (elementWithPriority) {
dynamicFetchPriority =
elementWithPriority === lcpEntry.element ? 'hit' : 'miss';
}
navigator.sendBeacon(
'/hint',
JSON.stringify({
path: originalPathname,
selector: target,
}),
);
if (lcpEntry?.url && lcpEntry.element?.tagName.toLowerCase() === 'img') {
const elementWithPriority = document.querySelector('[fetchpriority]');
if (elementWithPriority) {
dynamicFetchPriority =
elementWithPriority === lcpEntry.element ? 'hit' : 'miss';
}
navigator.sendBeacon(
'/hint',
JSON.stringify({
path: originalPathname,
selector: target,
}),
);
}

log.event(metric.name, {
value: metric.delta,
metric_rating: metric.rating,
metric_value: metric.value,
debug_target: target || '(not set)',
debug_url: metric.attribution.url,
debug_dfp: dynamicFetchPriority,
debug_ttfb: metric.attribution.timeToFirstByte,
debug_rld: metric.attribution.resourceLoadDelay,
debug_rlt: metric.attribution.resourceLoadDuration,
debug_erd: metric.attribution.elementRenderDelay,
event_id: metric.id,
});
},
{reportAllChanges: true},
);
return {
debug_target: target || '(not set)',
debug_url: metric.attribution.url,
debug_dfp: dynamicFetchPriority,
debug_ttfb: metric.attribution.timeToFirstByte,
debug_rld: metric.attribution.resourceLoadDelay,
debug_rlt: metric.attribution.resourceLoadDuration,
debug_erd: metric.attribution.elementRenderDelay,
};
});
};

const trackTTFB = () => {
Expand Down