feat: implement home winners selection logic with fallback handling and add integration tests

src/spa/homeWinnerSelection.ts

@@ -0,0 +1,26 @@
+import { resolveCmsRelationship, type CmsRouteDoc } from '@/spa/cmsRoute'
+
+const FALLBACK_YEAR = 2025
+const FALLBACK_LIMIT = 8
+
+type FallbackWinner = {
+  id: string | number
+  year?: string | number
+}
+
+export function resolveHomeWinners(
+  featured: unknown,
+  cmsWinners: CmsRouteDoc[],
+  fallbackWinners: FallbackWinner[],
+) {
+  const selectedWinners = Array.isArray(featured) ? featured : []
+  const selectedWinnerDocs = selectedWinners
+    .map((selected) => resolveCmsRelationship(selected, cmsWinners))
+    .filter((winner): winner is CmsRouteDoc => Boolean(winner))
+
+  if (selectedWinnerDocs.length) return selectedWinnerDocs
+
+  return (cmsWinners.length ? cmsWinners : fallbackWinners)
+    .filter((winner) => Number(winner.year) === FALLBACK_YEAR)
+    .slice(0, FALLBACK_LIMIT)
+}