Usage

const array = [
  { id: 1, name: "Fred" },
  { id: 2, name: "Annie" },
];

mapify(
  array,
  (item) => item.id,
  (item) => item.name,
);
// Map(2) { 1 => 'Fred', 2 => 'Annie' }

Installation

CLI

npx atmx add helper mapify

Manually

Copy and paste the following method into @/utils/helpers/mapify.ts:

/**
* Create a new `Map` instance from an array.
*
* @example
* const array = [
*   { id: 1, name: 'Fred' },
*   { id: 2, name: 'Annie' },
* ]
*
* mapify(
*   array,
*   item => item.id,
*   item => item.name,
* )
* // Map(2) { 1 => 'Fred', 2 => 'Annie' }
*/
export function mapify<T, Key, Value = T>(
array: readonly T[],
getKey: (item: T, index: number) => Key,
getValue: (item: T, index: number) => Value = (item) =>
item as unknown as Value,
): Map<Key, Value> {
const map: Map<Key, Value> = new Map();
for (const item of array) {
map.set(getKey(item, map.size), getValue(item, map.size));
}
return map;
}