Code Quiz

Measuring CLS in the Loading Pipeline

Spot the bug in a PerformanceObserver that reports Cumulative Layout Shift.

Codejavascript

let clsValue = 0;

const observer = new PerformanceObserver((list) => {
  for (const entry of list.getEntries()) {
    clsValue += entry.value;
  }
  console.log('Current CLS:', clsValue);
});

observer.observe({ type: 'layout-shift', buffered: true });

This code over-reports CLS. What is the bug and how do you fix it?

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