Component | RadialBar: Add barMinAngle config property

[rokotyan]

f5#863

Bars representing tiny values collapse into an invisible hairline: a value of 0.05% of the max is 0.4px of arc, which the browser paints as nothing. barMinAngle gives every bar a floor on its angular extent, the same idea as barMinHeight1Px in StackedBar, but expressed as an angle.

barMinAngle

• Radians, defaults to 0.01 — about one pixel wide on a ring of a 100 pixel radius, so small values stay perceptible out of the box. Set it to 0 to get the old behavior back, or raise it to make them prominent.
• Clamped to the length of angleRange — a value larger than the range simply fills it (last panel above).
• Applied along the sweep direction — reversed ranges, e.g. [0, -2 * Math.PI], keep rendering counter-clockwise.
• The floor only ever grows a bar: bars whose natural sweep is already wider are untouched.

Because the minimum is an angle, the same setting is thinner on inner rings (1.19px on the outermost ring vs 0.66px on the fourth, at the default). A pixel-exact floor would need a per-ring minWidthPx / outerRadius; happy to switch if that reads better.

0 vs missing data

The value accessor result used to be coerced with ?? 0, so a missing value and a real 0 were indistinguishable, and both drew nothing. They're now separate cases:

• 0 is a value — it gets barMinAngle and shows up as a small tick, so an empty metric is visibly empty rather than absent.
• null / undefined / non-finite is missing data — the arc stays collapsed and hidden, leaving only the background track.

RadialBarArcDatum.value is number | null accordingly, which is visible to tooltips and event handlers.

While wiring this up I also made the default id accessor null-safe: with gaps in the data the record itself can be null (data={[0.5, null, 0.2]}), which used to throw Cannot read properties of null (reading 'id') on the data join.

Docs

Included

• Core — barMinAngle config property, missing-value handling, null-safe default id accessor.
• Angular — the new @Input(). Hand-written to match the generated style: pnpm generate currently rewrites every component's imports into internal @/* alias paths, which don't resolve in that package (fallout from the alias migration, worth a separate fix). React / Vue / Svelte / Solid are generic over the config interface and need no change.
• Dev examples — Radial Bar Min Angle with the cases in the screenshot above.
• Docs — a Minimum Bar Angle section with a live slider, plus the 0-vs-missing distinction.

Verification

Measured the rendered bar bounding boxes in the dev app (rings of a ~107px radius, trackWidth: 14):

barMinAngle	tiny value (0.05%)	0 value	null value
0	0.38px	hidden	hidden
0.01 (default)	1.19px	0.66px	hidden
0.2	22.55px	11.98px	hidden

Also checked the docs demo across slider positions, half and reversed angle ranges, padAngle interplay, and clamping. tsc --noEmit and eslint are clean; both core commits compile in isolation.