react-doctor/js-batch-dom-css

Batch DOM/CSS reads and writes: interleaving them inside a loop causes layout thrashing. Read first, then write

Validation prompt

Confirm the detector match and collect the required evidence before deciding whether an edit is warranted.

The rule fires when two or more adjacent ExpressionStatements each assign to a .style.<prop> chain (e.g. el.style.color = '...'; el.style.fontSize = '...';). It does not actually detect interleaved read/write layout thrashing: just adjacent style writes. False positive if the writes target different elements or are intentionally split around conditional logic that has to sit between them.

Evidence boundary

The diagnostic proves only that the detector’s modeled source pattern matched. It does not prove runtime impact, product intent, rendered failure, or that one remediation is correct.

Establish the environment, repository policy, exceptions, and required rendered or runtime evidence before deciding the occurrence.

Record one outcome:

• Confirmed failure: The required evidence establishes the violation.
• Rejected: A documented exception or false-positive predicate applies.
• Needs evidence: Named evidence can still be collected.
• Unavailable: Required evidence cannot be collected in this run.
• Waived with evidence: An authorized, scoped exception applies to an established failure.
• Observation: The review records an optional tradeoff without claiming a defect.

A waiver records its scope, authority, evidence, and review condition. It is not a pass or false positive.

Default severity is registry metadata. Use the occurrence’s JSON severity after repository configuration when ordering real findings.

Fix prompt

Apply this candidate correction only after the required evidence confirms the risk.

Batch into a single write: el.style.cssText = 'color: red; font-size: 12px' or el.setAttribute('style', '...'). Better, define a class in CSS and toggle with el.classList.add('active') to keep styling out of JS. If inside a loop with reads, do all reads first then all writes in a second pass to avoid forced synchronous layout. https://web.dev/articles/avoid-large-complex-layouts-and-layout-thrashing

Repository-wide copy prompt

Use this repository-wide prompt only after validating each occurrence. For one occurrence, use the guidance above.