Run results for: clone with change

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.81 Safari/537.36

Browser: Chrome 94

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
cloneWith	542581.1 Ops/sec
cloneWith2	800537.2 Ops/sec
mutate	1048162.6 Ops/sec

Script Preparation code:

class Holder {
    constructor(init) {
        Holder.internalAssign(this, init);
    }
    static has(instance, property) {
        return Object.prototype.hasOwnProperty.call(instance, property);
    }
    static internalAssign(target, source) {
        if (Holder.has(source, "a"))
            target.a = source.a;
        if (Holder.has(source, "b"))
            target.b = source.b;
        if (Holder.has(source, "c"))
            target.c = source.c;
    }
    clone() {
        return new Holder(this);
    }

    cloneWith(props) {
        const cloned = this.clone();
        Holder.internalAssign(cloned, props);
        return cloned;
    }
    cloneWith2(props) {
        const cloned = this.clone();
        Object.assign(this, props);
        return cloned;
    }

    mutate(mutation) {
        const cloned = this.clone();
        mutation(cloned);
        return cloned;
    }
}

var initHolder = new Holder({
    a: "value of a",
    b: "value of b",
    c: 1
});

Tests:

cloneWith
initHolder.cloneWith({ a: "changed a", b: "changed b" });
cloneWith2
initHolder.cloneWith2({ a: "changed a", b: "changed b" });
mutate
initHolder.mutate(x => { x.a = "changed a"; x.b = "changed b" });