feat(vue): expand @robonen/vue composable collection

Composables, tests, category barrels, and README for @robonen/vue.

vue/toolkit/src/composables/array/useArrayFindLast/index.ts

@@ -0,0 +1,48 @@
+import { computed, toValue } from 'vue';
+import type { ComputedRef, MaybeRefOrGetter } from 'vue';
+
+export type UseArrayFindLastReturn<T = unknown>
+  = ComputedRef<T | undefined>;
+
+/**
+ * `Array.prototype.findLast` polyfill for runtimes older than ES2023.
+ */
+function findLast<T>(
+  array: T[],
+  fn: (element: T, index: number, array: T[]) => unknown,
+): T | undefined {
+  let index = array.length;
+  while (index-- > 0) {
+    const element = array[index]!;
+    if (fn(element, index, array))
+      return element;
+  }
+  return undefined;
+}
+
+const hasNativeFindLast = typeof Array.prototype.findLast === 'function';
+
+/**
+ * @name useArrayFindLast
+ * @category Array
+ * @description Reactive `Array.prototype.findLast`.
+ *
+ * @param {MaybeRefOrGetter<MaybeRefOrGetter<T>[]>} list The source array (items can be reactive)
+ * @param {(element: T, index: number, array: T[]) => unknown} fn Predicate testing each element
+ * @returns {UseArrayFindLastReturn<T>} The last matching element, or `undefined` if none match
+ *
+ * @example
+ * const list = ref([1, 2, 3, 4]);
+ * const found = useArrayFindLast(list, n => n % 2 === 0); // 4
+ *
+ * @since 0.0.15
+ */
+export function useArrayFindLast<T>(
+  list: MaybeRefOrGetter<Array<MaybeRefOrGetter<T>>>,
+  fn: (element: T, index: number, array: T[]) => unknown,
+): UseArrayFindLastReturn<T> {
+  return computed(() => {
+    const resolved = toValue(list).map(item => toValue(item));
+    return hasNativeFindLast ? resolved.findLast(fn) : findLast(resolved, fn);
+  });
+}