Reviewing Animations
Review motion in the requested scope against a high craft bar. Follow the user's requested review scope and output format; for a mixed review, apply this method to the motion portion and use the appropriate method for the remaining code.
Review method
- Identify affected interactions, target platform, input modes, motion primitives, and existing product tokens. Inspect surrounding lifecycle code as needed.
- Trace entry, exit, cancellation, reversal, repeated input, and cleanup. Check accessibility equivalents and whether motion delays functional input.
- Observe the interaction when tools and runtime are available. Profile suspected rendering problems under representative load. Code inspection can prove a stale callback or missing cancellation path; it cannot establish subjective feel or actual dropped frames on its own.
- Report the smallest useful findings with location, trigger, impact, evidence, and a concrete correction. Do not manufacture findings to earn an approval verdict.
Standards with context
- Purpose and frequency: repeated actions should remain ready for immediate input. Keyboard-triggered motion is not automatically a defect.
- Response and timing: judge first feedback, readiness, and settling separately. Roughly 300 ms is a useful tuning reference for small UI, not a universal ceiling. Built-in easing, accelerating exits, and symmetric timings can be appropriate.
- Spatial coherence: scaling anchored overlays should communicate their source.
Centered modals, fades, deliberate morphs, and icon effects have different needs;
neither pure fade nor
scale(0)is automatically a violation. - Interruptibility: prove that reversal starts from a coherent visible state and that completion callbacks cannot corrupt newer state. Judge behavior rather than banning keyframes or assuming every spring preserves velocity.
- Rendering: prefer transform and opacity where they preserve intended behavior. Layout animation, clipping, blur, and library shorthand properties are investigation leads, not proof of poor performance. Check the installed version and target.
- Accessibility: honor the relevant platform's reduced-motion setting while keeping state changes, focus, and functionality intact. Static transitions are valid. Check touch, hover, and keyboard access where the changed interaction uses them.
- Cohesion: compare with surrounding product behavior. Blur, bounce, stagger, asymmetric timing, and custom curves are optional design choices.
CSS properties, browser compositing, media queries, and Pointer Events apply to web implementations. Do not apply them directly to React Native, Reanimated, or SwiftUI; inspect that platform's drivers, gesture lifecycle, and accessibility APIs instead.
References
STANDARDS.md routes to shared references by topic. Read only the reference needed for the interaction or finding. Tuning values support reasoning; they are not external requirements or substitutes for observed evidence.
Report and verdict
Separate these categories, omitting empty ones:
- Defects: reproducible or code-provable failures, with severity proportional to user impact. Include file/line, trigger, evidence, and a targeted fix.
- Design preferences: alternatives that may improve feel or consistency; explain the tradeoff without treating a house-style preference as a blocking bug.
- Needs visual verification: an unresolved concern with a specific scenario and check. State which environment or observation is missing.
Lead with material findings and end with a scoped conclusion: block for established material defects; approve when the inspected scope has no material findings; use a qualified conclusion when essential visual or device evidence is unavailable. State what was verified and what was not. Do not claim runtime verification from source inspection or require a findings table when prose is clearer.
Choose remedies by the demonstrated problem: remove unnecessary delay, reduce motion, correct lifecycle or origin, improve rendering, or add missing accessibility handling. Treat accessibility defects according to impact, not as final cosmetic polish. Do not add effects or rewrite unrelated components during a review unless the user also requested implementation.