Run results for: lodash.isEqual vs fast-deep-equal (only arrays)

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36

Browser: Chrome 136

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 10 months ago

Test name	Executions per second
lodash	25566.8 Ops/sec
fast-deep-equal	18217.2 Ops/sec

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.20/lodash.min.js"></script>

Script Preparation code:

function equal(a, b) {
    if (a === b) return true;

    if (a && b && typeof a == 'object' && typeof b == 'object') {
        if (a.constructor !== b.constructor) return false;

        var length, i, keys;
        if (Array.isArray(a)) {
            length = a.length;
            if (length != b.length) return false;
            for (i = length; i-- !== 0;)
                if (!equal(a[i], b[i])) return false;
            return true;
        }



        if (a.constructor === RegExp) return a.source === b.source && a.flags === b.flags;
        if (a.valueOf !== Object.prototype.valueOf) return a.valueOf() === b.valueOf();
        if (a.toString !== Object.prototype.toString) return a.toString() === b.toString();

        keys = Object.keys(a);
        length = keys.length;
        if (length !== Object.keys(b).length) return false;

        for (i = length; i-- !== 0;)
            if (!Object.prototype.hasOwnProperty.call(b, keys[i])) return false;

        for (i = length; i-- !== 0;) {
            var key = keys[i];

            if (!equal(a[key], b[key])) return false;
        }

        return true;
    }

    // true if both NaN, false otherwise
    return a !== a && b !== b;
};

// 1 level deep
var data = [

    {
        description: 'empty arrays',
        value1: [],
        value2: [],
        equal: true,
    },
    {
        description: 'different length arrays',
        value1: [1, 2, 3],
        value2: [1, 2],
        equal: false,
    },
    {
        description: 'arrays with different types',
        value1: [1, 2, 3],
        value2: ['1', '2', '3'],
        equal: false,
    },
    {
        description: 'arrays with null/undefined',
        value1: [1, null, 3],
        value2: [1, undefined, 3],
        equal: false,
    },
    {
        description: 'arrays with NaN',
        value1: [1, NaN, 3],
        value2: [1, NaN, 3],
        equal: true,
    },
    {
        description: 'large number arrays',
        value1: Array.from({
            length: 10000
        }, (_, i) => i),
        value2: Array.from({
            length: 10000
        }, (_, i) => i),
        equal: true,
    },
    {
        description: 'large string arrays',
        value1: Array.from({
            length: 1000
        }, (_, i) => `string${i}`),
        value2: Array.from({
            length: 1000
        }, (_, i) => `string${i}`),
        equal: true,
    },
    {
        description: 'mixed primitive arrays',
        value1: [1, 'hello', true, null, undefined, NaN],
        value2: [1, 'hello', true, null, undefined, NaN],
        equal: true,
    },
    {
        description: 'sparse arrays',
        value1: [1, , 3],
        value2: [1, undefined, 3],
        equal: false,
    },
    {
        description: 'arrays with special numbers',
        value1: [0, -0, Infinity, -Infinity],
        value2: [0, -0, Infinity, -Infinity],
        equal: true,
    },

];

Tests:

lodash
data.forEach((item) => { _.isEqual(item.value1, item.value2); });
fast-deep-equal
data.forEach((item) => { equal(item.value1, item.value2); });