Visx

visx

Use this skill when work touches Airbnb visx (@visx/*) — low-level React visualization primitives, @visx/xychart, interaction packages, specialized layouts, or v3→v4 migration.

Treat 4.0.0 as the published stable line (React 18/19). Prefer package-root imports, gallery sandboxes at the installed tag, and GitHub/visx.airbnb.tech over stale deep-import snippets. Mark 4.1 packages (@visx/theme, @visx/a11y, @visx/chart, @visx/kernel, registry) as not installable until they appear on npm.

Workflow

1. Confirm the local surface before changing code:
   • All @visx/* versions aligned on the same major (prefer ^4.0.0); do not mix v3 and v4.
   • React peers ^18 || ^19 (and matching @types/react / @types/react-dom when using TypeScript).
   • Whether the task is XYChart, primitive composition, or a specialized layout (geo/hierarchy/network/stats/…).
   • Animation peers: @react-spring/web only when importing Animated* from @visx/xychart or @visx/react-spring.
2. Refresh package evidence and docs URLs from source-map.md.
3. For install strategy, mental model, scales, shapes, curves, glyphs, markers, text, defs (clip/pattern/gradient), and @visx/vendor, use setup-core.md.
4. For axes, grids, legends, annotations, threshold bands, and theming/a11y (4.0 XYChart + 4.1 preview), use guides-decoration.md.
5. For ParentSize, bounds, localPoint, drag, brush, zoom, and tooltips/portals, use interaction-layout.md.
6. For stats, heatmap, hierarchy, network, sankey, chord, geo, voronoi/delaunay, wordcloud, and kernel clarifications, use specialized-viz.md.
7. For XYChart series/providers/themes, react-spring, mock-data, and the @visx/visx umbrella, use xychart-high-level.md.
8. For v3→v4 migration, decision guide, production/SSR/a11y/perf, and AI authoring traps, use production-migration.md.

Implementation Judgment

• visx is not a batteries-included charting library. Compose SVG: dimensions → scales → marks/guides → interaction. Prefer the smallest @visx/* set that answers the job.
• D3 computes; React owns the DOM. Scales and shape factories produce numbers/path d strings; components render SVG. Do not mix d3 selections/enter/exit into visx mark trees.
• Invert continuous y ranges ([innerHeight, 0]). SVG y grows downward.
• Use named package-root imports (import { Bar } from '@visx/shape'). Never deep-import @visx/*/lib/... under v4 exports.
• Prefer @visx/vendor/d3-* (or declare your own d3-*) over accidental transitive D3 imports. Do not duplicate vendor + bare d3-shape/d3-scale without intent.
• XYChart for standard cartesian line/area/bar/glyph/stack/group with shared tooltip/theme/annotations. Pass ScaleConfig objects ({ type: 'band' }), not live d3 scale instances, into xScale/yScale.
• Primitives for polar, geo, hierarchy, network, stats, custom SVG structure, or minimal bundles.
• Prefer @visx/delaunay over legacy @visx/voronoi for new Voronoi/hit-target work.
• @visx/network does not run force layout — supply x/y (e.g. via external d3-force).
• @visx/kernel is not KDE. Density → @visx/stats bins/ViolinPlot or external KDE + @visx/shape.
• Wrap responsive charts in ParentSize / useParentSize; guard width < 10 before rendering. Supply fixed sizes in tests/SSR.
• Memoize scale configs and expensive layouts against width/height/data. Treat mutable d3 scales carefully across renders.
• Unique SVG ids for gradients, patterns, markers, clipPaths, and Threshold clips — especially with multiple charts on one page.
• Keep decorative chrome (Grid*, Axis*, backgrounds) aria-hidden when adding chart semantics; use XYChart accessibilityLabel / series focus handlers on 4.0.0.

Verification

Prefer the repo's existing checks. For meaningful visx changes, include the relevant subset:

• Package/version check proving aligned @visx/*@^4 and React 18/19 peers (plus @react-spring/web when Animated* is used).
• Typecheck for accessors, ScaleInput, series Datum/dataKey, axis/grid props, and tooltip state — no deep-import types.
• Deterministic SVG assertions with fixed width/height (mock ResizeObserver when ParentSize/tooltip portal is involved).
• Interaction tests for tooltip show/hide, brush domain filter, zoom reset, and keyboard focus when those APIs change.
• Visual smoke for theme tokens, stacked/grouped bars, and annotation placement.
• Bundle/import audit when adding umbrella @visx/visx, animation, geo TopoJSON, or large hierarchy/network demos.
• Migration scan for deep imports, React 16/17 peers, missing nodeRef on withBoundingRects, and parentRef.current after useParentSize.