Skip non-interaction event entries when computing INP#2456
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soulgalore merged 1 commit intomainfrom May 4, 2026
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The two INP scripts (interactionToNextPaint.js and interactionToNextPaintInfo.js) walk the buffered `event` and `first-input` PerformanceObserver records, but unlike web-vitals' upstream `lib/interactions.ts` they don't filter to entries with `interactionId > 0`. The browser only assigns a non-zero interactionId to events that are part of a discrete user interaction (a click's pointerdown/up, keydown/up, etc.); a bare `pointerover` from a stationary OS cursor that happens to be over content as it paints gets `interactionId === 0`. Without that guard automated runs regularly report INP from the cursor passing under freshly-rendered content during navigation. The hover entries land under `longestInteractionMap[0]`, are treated as a single "interaction" with ever-growing latency, and when no real user interaction happens during the iteration that synthetic value is what gets returned. The DevTools-trace variant of this code (`lib/chrome/webdriver/devtools/inp.js`) already has the `entry.interactionId > 0` guard, so the rest of the codebase already treats it as the right shape. Add `if (!entry.interactionId) continue;` at the top of the processing loop in both scripts to match web-vitals. Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com> Change-Id: Ia574f1d734f9b7d5b5b32174c580c9effd43f629
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The two INP scripts (interactionToNextPaint.js and interactionToNextPaintInfo.js) walk the buffered
eventandfirst-inputPerformanceObserver records, but unlike web-vitals' upstreamlib/interactions.tsthey don't filter to entries withinteractionId > 0. The browser only assigns a non-zero interactionId to events that are part of a discrete user interaction (a click's pointerdown/up, keydown/up, etc.); a barepointeroverfrom a stationary OS cursor that happens to be over content as it paints getsinteractionId === 0.Without that guard automated runs regularly report INP from the cursor passing under freshly-rendered content during navigation. The hover entries land under
longestInteractionMap[0], are treated as a single "interaction" with ever-growing latency, and when no real user interaction happens during the iteration that synthetic value is what gets returned. The DevTools-trace variant of this code (lib/chrome/webdriver/devtools/inp.js) already has theentry.interactionId > 0guard, so the rest of the codebase already treats it as the right shape.Add
if (!entry.interactionId) continue;at the top of the processing loop in both scripts to match web-vitals.Change-Id: Ia574f1d734f9b7d5b5b32174c580c9effd43f629