@woosh/meep-engine/src/core/collection/array/array_push_if_unique.js

Pure JavaScript game engine. Fully featured and production ready.

import { assert } from "../../assert.js";

/**
 * Adds an element to the end of the array, iff the element is not present in the array already
 * @template T
 * @param {T[]} array where
 * @param {T} element what to add
 * @return {boolean} true iff added, false if the array already contains this element
 */
export function array_push_if_unique(array, element) {
    assert.isArray(array, 'array');

    const i = array.indexOf(element);

    if (i === -1) {
        array.push(element);
        return true;
    }

    return false;
}