UseMap

1'use client';
2 
3import { useCallback, useMemo, useState } from 'react';
4 
5export type UseMapResult<K, V> = {
6  map: Map<K, V>;
7  set: (key: K, value: V) => void;
8  delete: (key: K) => void;
9  has: (key: K) => boolean;
10  clear: () => void;
11  reset: () => void;
12  setValue: (newMap: Map<K, V>) => void;
13  get: (key: K) => V | undefined;
14  getAll: () => [K, V][];
15};
16 
17export function useMap<K, V>(
18  initialMap: Iterable<[K, V]> = [],
19): UseMapResult<K, V> {
20  const [map, setMap] = useState<Map<K, V>>(() => new Map(initialMap));
21  const initial = useMemo(() => new Map(initialMap), [initialMap]);
22 
23  const setEntry = useCallback((key: K, value: V) => {
24    setMap((prev) => {
25      const current = prev.get(key);
26      if (prev.has(key) && current === value) return prev;
27      const next = new Map(prev);
28      next.set(key, value);
29      return next;
30    });
31  }, []);
32 
33  const deleteEntry = useCallback((key: K) => {
34    setMap((prev) => {
35      if (!prev.has(key)) return prev;
36      const next = new Map(prev);
37      next.delete(key);
38      return next;
39    });
40  }, []);
41 
42  const hasKey = useCallback((key: K) => map.has(key), [map]);
43 
44  const clear = useCallback(() => {
45    setMap(new Map());
46  }, []);
47 
48  const reset = useCallback(() => {
49    setMap(new Map(initial));
50  }, [initial]);
51 
52  const setValue = useCallback((newMap: Map<K, V>) => {
53    setMap(new Map(newMap));
54  }, []);
55 
56  const get = useCallback((key: K) => map.get(key), [map]);
57 
58  const getAll = useCallback(() => Array.from(map.entries()), [map]);
59 
60  return {
61    map,
62    set: setEntry,
63    delete: deleteEntry,
64    has: hasKey,
65    clear,
66    reset,
67    setValue,
68    get,
69    getAll,
70  };
71}