Function formatChange

src/lib/format.ts:12–23

(delta: number | null)

}

export function formatChange(delta: number | null): {
  text: string;
  cls: "up" | "down" | "neutral";
} {
  if (delta === null || delta === undefined || isNaN(delta))
    return { text: "—", cls: "neutral" };
  const sign = delta >= 0 ? "+" : "";
  return {
    text: `${sign}${(delta * 100).toFixed(1)}%`,
    cls: delta > 0.001 ? "up" : delta < -0.001 ? "down" : "neutral",
  };
}