📝 Commit Details:

backend/node_modules/date-fns/differenceInISOWeekYears.js

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+import { normalizeDates } from "./_lib/normalizeDates.js";
+import { compareAsc } from "./compareAsc.js";
+import { differenceInCalendarISOWeekYears } from "./differenceInCalendarISOWeekYears.js";
+import { subISOWeekYears } from "./subISOWeekYears.js";
+
+/**
+ * The {@link differenceInISOWeekYears} function options.
+ */
+
+/**
+ * @name differenceInISOWeekYears
+ * @category ISO Week-Numbering Year Helpers
+ * @summary Get the number of full ISO week-numbering years between the given dates.
+ *
+ * @description
+ * Get the number of full ISO week-numbering years between the given dates.
+ *
+ * ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date
+ *
+ * @param laterDate - The later date
+ * @param earlierDate - The earlier date
+ * @param options - The options
+ *
+ * @returns The number of full ISO week-numbering years
+ *
+ * @example
+ * // How many full ISO week-numbering years are between 1 January 2010 and 1 January 2012?
+ * const result = differenceInISOWeekYears(
+ *   new Date(2012, 0, 1),
+ *   new Date(2010, 0, 1)
+ * )
+ * // => 1
+ */
+export function differenceInISOWeekYears(laterDate, earlierDate, options) {
+  const [laterDate_, earlierDate_] = normalizeDates(
+    options?.in,
+    laterDate,
+    earlierDate,
+  );
+
+  const sign = compareAsc(laterDate_, earlierDate_);
+  const diff = Math.abs(
+    differenceInCalendarISOWeekYears(laterDate_, earlierDate_, options),
+  );
+
+  const adjustedDate = subISOWeekYears(laterDate_, sign * diff, options);
+
+  const isLastISOWeekYearNotFull = Number(
+    compareAsc(adjustedDate, earlierDate_) === -sign,
+  );
+  const result = sign * (diff - isLastISOWeekYearNotFull);
+
+  // Prevent negative zero
+  return result === 0 ? 0 : result;
+}
+
+// Fallback for modularized imports:
+export default differenceInISOWeekYears;