bootstrap-vue/src/utils/array.js

Quickly integrate Bootstrap 4 components with Vue.js

// Production steps of ECMA-262, Edition 6, 22.1.2.1
// es6-ified by @alexsasharegan
if (!Array.from) {
    Array.from = (function() {
        const toStr = Object.prototype.toString;
        const isCallable = fn => typeof fn === "function" || toStr.call(fn) === "[object Function]";
        const toInteger = value => {
            const number = Number(value);
            if (isNaN(number)) {
                return 0;
            }
            if (number === 0 || !isFinite(number)) {
                return number;
            }
            return (number > 0 ? 1 : -1) * Math.floor(Math.abs(number));
        };
        const maxSafeInteger = Math.pow(2, 53) - 1;
        const toLength = value => Math.min(Math.max(toInteger(value), 0), maxSafeInteger);

        // The length property of the from method is 1.
        return function from(arrayLike /*, mapFn, thisArg */) {
            // 1. Let C be the this value.
            const C = this;

            // 2. Let items be ToObject(arrayLike).
            const items = Object(arrayLike);

            // 3. ReturnIfAbrupt(items).
            if (arrayLike == null) {
                throw new TypeError("Array.from requires an array-like object - not null or undefined");
            }

            // 4. If mapfn is undefined, then let mapping be false.
            const mapFn = arguments.length > 1 ? arguments[1] : void undefined;
            let T;

            if (typeof mapFn !== "undefined") {
                // 5. else
                // 5. a If IsCallable(mapfn) is false, throw a TypeError exception.
                if (!isCallable(mapFn)) {
                    throw new TypeError("Array.from: when provided, the second argument must be a function");
                }

                // 5. b. If thisArg was supplied, let T be thisArg; else let T be undefined.
                if (arguments.length > 2) {
                    T = arguments[2];
                }
            }

            // 10. Let lenValue be Get(items, "length").
            // 11. Let len be ToLength(lenValue).
            const len = toLength(items.length);

            // 13. If IsConstructor(C) is true, then
            // 13. a. Let A be the result of calling the [[Construct]] internal method
            // of C with an argument list containing the single item len.
            // 14. a. Else, Let A be ArrayCreate(len).
            let A = isCallable(C) ? Object(new C(len)) : new Array(len);

            // 16. Let k be 0.
            let k = 0;
            // 17. Repeat, while k < len… (also steps a - h)
            let kValue;
            while (k < len) {
                kValue = items[k];
                if (mapFn) {
                    A[k] = typeof T === "undefined" ? mapFn(kValue, k) : mapFn.call(T, kValue, k);
                } else {
                    A[k] = kValue;
                }
                k += 1;
            }
            // 18. Let putStatus be Put(A, "length", len, true).
            A.length = len;
            // 20. Return A.
            return A;
        };
    })();
}

// https://tc39.github.io/ecma262/#sec-array.prototype.find
// Needed for IE support
if (!Array.prototype.find) {
    Object.defineProperty(Array.prototype, 'find', {
        value: function(predicate) {
            // 1. Let O be ? ToObject(this value).
            if (this == null) {
                throw new TypeError('"this" is null or not defined');
            }

            const o = Object(this);

            // 2. Let len be ? ToLength(? Get(O, "length")).
            const len = o.length >>> 0;

            // 3. If IsCallable(predicate) is false, throw a TypeError exception.
            if (typeof predicate !== 'function') {
                throw new TypeError('predicate must be a function');
            }

            // 4. If thisArg was supplied, let T be thisArg; else let T be undefined.
            const thisArg = arguments[1];

            // 5. Let k be 0.
            let k = 0;

            // 6. Repeat, while k < len
            while (k < len) {
                // a. Let Pk be ! ToString(k).
                // b. Let kValue be ? Get(O, Pk).
                // c. Let testResult be ToBoolean(? Call(predicate, T, « kValue, k, O »)).
                // d. If testResult is true, return kValue.
                const kValue = o[k];
                if (predicate.call(thisArg, kValue, k, o)) {
                    return kValue;
                }
                // e. Increase k by 1.
                k++;
            }

            // 7. Return undefined.
            return undefined;
        }
    });
}

if (!Array.isArray) {
    Array.isArray = arg => Object.prototype.toString.call(arg) === "[object Array]";
}

// Static
export const from = Array.from;
export const isArray = Array.isArray;

// Instance
export const arrayIncludes = (array, value) => array.indexOf(value) !== -1;
export const arrayFind = (array, fn, thisArg) => array.find(fn, thisArg);
export function concat() {
    return Array.prototype.concat.apply([], arguments);
}