Usage

unique([1, 1, 2, 2]); // => [1, 2]
unique([1, 2, 3], (n) => n % 2); // => [1, 2]

Installation

CLI

npx atmx add helper unique

Manually

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

/**
* Given a list of items returns a new list with only unique items.
* Accepts an optional identity function to convert each item in the
* list to a comparable identity value.
*
* @example
* unique([1, 1, 2, 2]) // => [1, 2]
* unique([1, 2, 3], (n) => n % 2) // => [1, 2]
*/
export function unique<T, K = T>(
array: readonly T[],
toKey?: (item: T) => K,
): T[] {
if (toKey) {
const keys = new Set<K>();
return array.reduce((acc, item) => {
  const key = toKey(item);
  if (!keys.has(key)) {
    keys.add(key);
    acc.push(item);
  }
  return acc;
}, [] as T[]);
}
return [...new Set(array)];
}