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- import { initMetric } from './lib/initMetric.js';
- import { observe } from './lib/observe.js';
- import { onHidden } from './lib/onHidden.js';
- import { onBFCacheRestore } from './lib/onBFCacheRestore.js';
- import { bindReporter } from './lib/bindReporter.js';
- export const getCLS = (onReport, reportAllChanges) => {
- let metric = initMetric('CLS', 0);
- let report;
- const entryHandler = (entry) => {
-
- if (!entry.hadRecentInput) {
- metric.value += entry.value;
- metric.entries.push(entry);
- report();
- }
- };
- const po = observe('layout-shift', entryHandler);
- if (po) {
- report = bindReporter(onReport, metric, reportAllChanges);
- onHidden(() => {
- po.takeRecords().map(entryHandler);
- report();
- });
- onBFCacheRestore(() => {
- metric = initMetric('CLS', 0);
- report = bindReporter(onReport, metric, reportAllChanges);
- });
- }
- };
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