Run results for: IMMUTABLE COPY

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/111.0.0.0 Safari/537.36

Browser: Chrome 111

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Immutable	367857.3 Ops/sec
Lodash	476219.5 Ops/sec
Manual	1393155.0 Ops/sec
Assign	2989129.0 Ops/sec
so	6785814.0 Ops/sec

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>
<script src='https://cdnjs.cloudflare.com/ajax/libs/immutable/3.8.2/immutable.min.js'></script>
<script>
    function copyDeep(value) {
        if (!value)
            return value;
        if (value.constructor === Array) {
            return value.map(copyDeep);
        }
        if (value.constructor === Object) {
            const copy = {};
            for (let k in value) {
                copy[k] = copyDeep(value[k]);
            }
            return copy;
        }
        return value;
    }

    function merge(target, src) {
        if (!target || !src || target.constructor != Object || src.constructor !== Object) return target;
        for (var key in src) {
            if (target[key]) {
                if (target[key].constructor === Object && src[key].constructor === Object) {
                    target[key] = merge(target[key], src[key]);
                } else {
                    target[key] = src[key];
                }
            } else {
                target[key] = src[key];
            }
        }
    }
</script>

Script Preparation code:

var MyObject = {
    description: 'Creates a deep copy of source, which should be an object or an array.',
    myNumber: 123456789,
    myBoolean: true,
    jayson: {
        stringify: 'JSON.stringify() method converts a JavaScript value to a JSON string....',
        parse: 'JSON.parse() method parses a JSON string...'
    }
};

var myCopy = null;

Tests:

Immutable
myCopy = Immutable.fromJS(MyObject).mergeDeep({ jayson: {parse: 'JSON.parse() method parses a JSON string... 2'}}).toJS()
Lodash
myCopy = _.merge(_.cloneDeep(MyObject), { jayson: {parse: 'JSON.parse() method parses a JSON string... 2'}})
Manual
myCopy = merge(copyDeep(MyObject), { jayson: {parse: 'JSON.parse() method parses a JSON string... 2'}});
Assign
myCopy = Object.assign({}, MyObject, { jayson: {parse: 'JSON.parse() method parses a JSON string... 2'}});
so
myCopy = { ...MyObject, jayson: {parse: 'JSON.parse() method parses a JSON string... 2'}}

Run results for: IMMUTABLE COPY

Immutable

Lodash

Manual

Assign

so