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

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"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.filter = filter;
exports.reject = reject;
const is_1 = require("../utils/is");
/**
 * Iterates over elements of collection, returning an array of all elements
 * the predicate returns truthy for.
 *
 * @param collection - The collection to iterate over
 * @param predicate - The function invoked per iteration
 * @returns The new filtered array
 *
 * @example
 * ```ts
 * const users = [
 *   { 'user': 'barney', 'age': 36, 'active': true },
 *   { 'user': 'fred',   'age': 40, 'active': false }
 * ];
 *
 * filter(users, function(o) { return !o.active; });
 * // => objects for ['fred']
 *
 * // The `_.matches` iteratee shorthand.
 * filter(users, { 'age': 36, 'active': true });
 * // => objects for ['barney']
 *
 * // The `_.matchesProperty` iteratee shorthand.
 * filter(users, ['active', false]);
 * // => objects for ['fred']
 *
 * // The `_.property` iteratee shorthand.
 * filter(users, 'active');
 * // => objects for ['barney']
 * ```
 */
function filter(collection, predicate) {
    if (!collection || !collection.length) {
        return [];
    }
    // Convert predicate to a function if it's not already one
    let predicateFn;
    if (typeof predicate === 'function') {
        // Function predicate
        predicateFn = predicate;
    }
    else if ((0, is_1.isArray)(predicate) && predicate.length === 2) {
        // Property and value pair
        const [prop, value] = predicate;
        predicateFn = (item) => {
            return (0, is_1.isObject)(item) && item[prop] === value;
        };
    }
    else if ((0, is_1.isObject)(predicate)) {
        // Object matching
        predicateFn = (item) => {
            if (!(0, is_1.isObject)(item))
                return false;
            const objItem = item;
            const objPred = predicate;
            for (const key in objPred) {
                if (objItem[key] !== objPred[key]) {
                    return false;
                }
            }
            return true;
        };
    }
    else if (typeof predicate === 'string') {
        // Property name
        const prop = predicate;
        predicateFn = (item) => {
            return (0, is_1.isObject)(item) && Boolean(item[prop]);
        };
    }
    else {
        // Default to identity function
        predicateFn = Boolean;
    }
    return collection.filter(predicateFn);
}
/**
 * The opposite of filter; this method returns the elements of collection
 * that predicate does NOT return truthy for.
 *
 * @param collection - The collection to iterate over
 * @param predicate - The function invoked per iteration
 * @returns The new filtered array
 *
 * @example
 * ```ts
 * const users = [
 *   { 'user': 'barney', 'age': 36, 'active': false },
 *   { 'user': 'fred',   'age': 40, 'active': true }
 * ];
 *
 * reject(users, function(o) { return !o.active; });
 * // => objects for ['fred']
 * ```
 */
function reject(collection, predicate) {
    // Reuse filter but negate the predicate
    const filterPredicate = typeof predicate === 'function'
        ? (value, index, collection) => !predicate(value, index, collection)
        : (value) => !filter([value], predicate).length;
    return filter(collection, filterPredicate);
}