Function selectTopDimensions

packages/db/src/services/insights/utils.ts:130–151

(
  currentMap: Map<string, number>,
  baselineMap: Map<string, number>,
  maxDims: number,
)

 * @returns Array of dimension keys, ranked by greatest(current, baseline)
 */
export function selectTopDimensions(
  currentMap: Map<string, number>,
  baselineMap: Map<string, number>,
  maxDims: number,
): string[] {
  // Merge all dimensions from both maps
  const allDims = new Set<string>();
  for (const dim of currentMap.keys()) allDims.add(dim);
  for (const dim of baselineMap.keys()) allDims.add(dim);

  // Rank by greatest(current, baseline)
  const ranked = Array.from(allDims)
    .map((dim) => ({
      dim,
      maxValue: Math.max(currentMap.get(dim) ?? 0, baselineMap.get(dim) ?? 0),
    }))
    .sort((a, b) => b.maxValue - a.maxValue)
    .slice(0, maxDims)
    .map((x) => x.dim);

  return ranked;
}