super-utils-plus/dist/array/union.js

A superior alternative to Lodash with improved performance, TypeScript support, and developer experience

import { isEqual } from '../utils/is';
/**
 * Creates an array of unique values, in order, from all given arrays.
 *
 * @param arrays - The arrays to inspect
 * @returns The new array of combined unique values
 *
 * @example
 * ```ts
 * union([2], [1, 2]);
 * // => [2, 1]
 * ```
 */
export function union(...arrays) {
    if (!arrays.length) {
        return [];
    }
    return [...new Set(arrays.flat())];
}
/**
 * Creates an array of unique values, in order, from all given arrays
 * using deep equality comparison.
 *
 * @param arrays - The arrays to inspect
 * @returns The new array of combined unique values
 *
 * @example
 * ```ts
 * unionDeep([{ 'x': 1 }], [{ 'x': 1 }, { 'x': 2 }]);
 * // => [{ 'x': 1 }, { 'x': 2 }]
 * ```
 */
export function unionDeep(...arrays) {
    if (!arrays.length) {
        return [];
    }
    const result = [];
    const flattened = arrays.flat();
    for (const item of flattened) {
        // Only add if not already in result using deep equality
        if (!result.some(resultItem => isEqual(resultItem, item))) {
            result.push(item);
        }
    }
    return result;
}
/**
 * Creates an array of unique values, in order, from all given arrays
 * using a custom iteratee function.
 *
 * @param arrays - The arrays to inspect with the last argument being a function or property name
 * @returns The new array of combined unique values
 *
 * @example
 * ```ts
 * unionBy([2.1], [1.2, 2.3], Math.floor);
 * // => [2.1, 1.2]
 *
 * unionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
 * // => [{ 'x': 1 }, { 'x': 2 }]
 * ```
 */
export function unionBy(...arrays) {
    if (arrays.length <= 1) {
        return [];
    }
    const iteratee = arrays.pop();
    const iterateeFn = typeof iteratee === 'function'
        ? iteratee
        : (obj) => obj[iteratee];
    const flattened = arrays.flat();
    const result = [];
    const seen = new Set();
    for (const item of flattened) {
        const transformed = iterateeFn(item);
        // Check if we've seen this transformed value before
        if (!seen.has(transformed)) {
            seen.add(transformed);
            result.push(item);
        }
    }
    return result;
}