prependToArray - API reference

API reference › @evolu/common › Array › prependToArray

function prependToArray<T>(array: readonly T[], item: T): readonly [T, T];

Defined in: packages/common/src/Array.ts:411

Prepends an item to an array, returning a new non-empty readonly array.

Prepending a value

import {
  assertEqual,
  assertType,
  prependToArray,
  type NonEmptyReadonlyArray,
} from "@evolu/common";

const values = prependToArray([2, 3], 1);
assertEqual(values, [1, 2, 3]);
assertType<NonEmptyReadonlyArray<number>, typeof values>();