🐛 Y-axis minRange floor skipped for tiny nonzero spans (can freeze tab)

[itsdiay]

Summary

In computeRange (and the candle range helper), the absolute Y floor uses a falsy coalesce:

const minRange = rawRange * 0.1 || 0.4

Because || only falls through when the left side is exactly 0 / falsy, any tiny nonzero rawRange skips the 0.4 floor.

Impact

Near-flat or micro-priced series (common for low-priced tokens) produce a denormal-scale Y domain. That domain is then used by the Y-grid drawing loop (drawGrid / pickInterval). With a step size smaller than the floating-point ULP of the current value, val += fine never advances and the main thread hangs → browser “Page Unresponsive”.

Expected

• When rawRange > 0 and finite, use the relative minimum span (rawRange * k).
• Apply the absolute floor (0.4, or 0.04 in exaggerate mode) only when the span is zero / non-finite.
• Avoid forcing 0.4 for all tiny nonzero spans (that over-pads and flattens real micro volatility).

Suggested fix direction

Replace the || pattern with an explicit check, e.g.:

const relativeMin = rawRange * (exaggerate ? 0.02 : 0.1)
const absoluteFloor = exaggerate ? 0.04 : 0.4
const minRange =
  rawRange > 0 && Number.isFinite(rawRange) ? relativeMin : absoluteFloor

Apply the same change to the candle range helper that currently uses range * 0.1 || 0.4.

Related

Grid-loop hardening (guards in pickInterval / drawGrid) is a useful defense-in-depth companion, but this floor bug is the primary domain-side cause of the hang for micro ranges.

Environment

Seen with liveline@0.0.7 in a React web app plotting USD prices around 1e-4–1e-5 with small relative moves.