Function resolveRowTrendPoints

resolveRowTrendPoints(
    product: Product,
    displayedVariants: readonly Variant[],
    history: ReadonlyMap<string, PriceHistoryEntry>,
): undefined | readonly PricePoint[]

Resolve the price series a results-table row should graph, shared by the collapsed trend column and the expanded detail panel so the two never diverge. A flattened variant row (identified by its stamped Product.priceSeriesKey) graphs its own variant series; any other row graphs the mean of its displayed variants (see buildAggregateSeries), falling back to the base product series. Returns undefined when there aren't two points to draw a line.

Parameters

product: Product
The row's product.
displayedVariants: readonly Variant[]
The variants shown for this row (already deduped by resolveDisplayedVariants); ignored for a flattened variant row.
history: ReadonlyMap<string, PriceHistoryEntry>
Recorded series keyed by series id (from getProductPriceHistory or a bulk preload).

Returns undefined | readonly PricePoint[]

The points to graph, or undefined when there's no drawable trend.

Example

const points = resolveRowTrendPoints(product, displayedVariants, history);
if (points) render(<PriceSparkline points={points} />);

Source

export function resolveRowTrendPoints(
  product: Product,
  displayedVariants: readonly Variant[],
  history: ReadonlyMap<string, PriceHistoryEntry>,
): readonly PricePoint[] | undefined {
  if (product.priceSeriesKey !== undefined) {
    const points = history.get(product.priceSeriesKey)?.points;
    return points !== undefined && points.length >= 2 ? points : undefined;
  }

  const productKey = productSeriesKey(product);
  const seriesFor = (variant: Variant): PriceHistoryEntry | undefined => {
    const key = variant === product ? productKey : variantSeriesKey(product, variant);
    return key !== undefined ? history.get(key) : undefined;
  };
  const displayedSeries = displayedVariants
    .map(seriesFor)
    .filter((series): series is PriceHistoryEntry => series !== undefined);
  const basePoints = productKey !== undefined ? history.get(productKey)?.points : undefined;
  const aggregate = displayedSeries.length > 0 ? buildAggregateSeries(displayedSeries) : basePoints;
  return aggregate !== undefined && aggregate.length >= 2 ? aggregate : undefined;
}