Badge updates do not trigger excessive background CPU usage

Badge update calls fired on every high-frequency browser event — webRequest.onCompleted, tabs.onUpdated, or sub-5-second polling — create continuous background CPU load even when the user is doing nothing extension-related. ISO 25010:2011 performance-efficiency.resource-utilisation treats unnecessary background CPU consumption as a defect. On laptops, this translates directly to battery drain; on lower-end hardware it causes system-wide slowdown. Chrome surfaces extensions that abuse background resources in its Task Manager, leading to removal.

Debounce badge updates so high-frequency trigger events coalesce into at most one update per 500ms, and skip the setBadgeText call entirely when the value has not changed.

let currentBadgeText = '';
let badgeUpdateTimer = null;

function scheduleBadgeUpdate() {
  clearTimeout(badgeUpdateTimer);
  badgeUpdateTimer = setTimeout(async () => {
    const count = await computeCount();
    const newText = count > 0 ? String(count) : '';
    if (newText !== currentBadgeText) {
      currentBadgeText = newText;
      chrome.action.setBadgeText({ text: newText });
    }
  }, 500);
}

For polling patterns, use chrome.alarms with a minimum 30-second interval and add idle detection via chrome.idle to pause updates when the system is idle.

• ID: extension-ux-performance.badge-notifications.badge-cpu-usage

• Severity: medium

• What to look for: Examine how frequently the badge is updated. Look for patterns that update the badge on very high-frequency events: every webRequest event, every onMessage, every tabs.onUpdated, or on a very short polling interval (under 5 seconds). Each chrome.action.setBadgeText call has overhead. Check for redundant badge updates — setting the badge to the same value it already has. Count all instances found and enumerate each.

• Pass criteria: Badge updates are infrequent relative to their trigger events. High-frequency events are debounced before triggering badge updates. No unnecessary updates when the value has not changed. Polling intervals for badge-relevant data are reasonable (30 seconds or more). At least 1 implementation must be confirmed.

• Fail criteria: Badge update logic fires on every high-frequency event without debouncing. Badge is updated with the same value it already has (no change check before calling setBadgeText). Polling interval for badge data is shorter than 5 seconds with no idle detection.

• Skip (N/A) when: The extension does not use the badge API.

• Detail on fail: Describe the frequency issue. Example: "setBadgeText called on every chrome.webRequest.onCompleted event — fires 50-200 times per minute during normal browsing" or "Background polls for badge data every 2 seconds with no idle detection or caching."

• Remediation: Debounce badge updates and skip redundant calls:

  let currentBadgeText = '';
  let badgeUpdateTimer = null;
  
  function scheduleBadgeUpdate() {
    clearTimeout(badgeUpdateTimer);
    badgeUpdateTimer = setTimeout(async () => {
      const count = await computeCount();
      const newText = count > 0 ? String(count) : '';
      if (newText !== currentBadgeText) {
        currentBadgeText = newText;
        chrome.action.setBadgeText({ text: newText });
      }
    }, 500);  // Debounce: update at most every 500ms
  }