Deep Copy an object very fast

deepCopy.js

// deep copy:
// String, Number, undefined, null, Set, Map, typed Array, Object, Boolean, RegExp, Date, ArrayBuffer, Node
// Functions, Properties of types: (Primitive, Symbol)
// shallow copy (by reference):
// WeakMap, WeakSet, Symbol
// increased compatibility: IE, Node
var $jscomp = $jscomp || {};
$jscomp.scope = {};
$jscomp.ASSUME_ES5 = !1;
$jscomp.defineProperty = $jscomp.ASSUME_ES5 || "function" == typeof Object.defineProperties ? Object.defineProperty : function(a, b, c) {
    a != Array.prototype && a != Object.prototype && (a[b] = c.value)
};
$jscomp.getGlobal = function(a) {
    return "undefined" != typeof window && window === a ? a : "undefined" != typeof global && null != global ? global : a
};
$jscomp.global = $jscomp.getGlobal(this);
$jscomp.SYMBOL_PREFIX = "jscomp_symbol_";
$jscomp.initSymbol = function() {
    $jscomp.initSymbol = function() {};
    $jscomp.global.Symbol || ($jscomp.global.Symbol = $jscomp.Symbol)
};
$jscomp.Symbol = function() {
    var a = 0;
    return function(b) {
        return $jscomp.SYMBOL_PREFIX + (b || "") + a++
    }
}();
$jscomp.initSymbolIterator = function() {
    $jscomp.initSymbol();
    var a = $jscomp.global.Symbol.iterator;
    a || (a = $jscomp.global.Symbol.iterator = $jscomp.global.Symbol("iterator"));
    "function" != typeof Array.prototype[a] && $jscomp.defineProperty(Array.prototype, a, {
        configurable: !0,
        writable: !0,
        value: function() {
            return $jscomp.arrayIterator(this)
        }
    });
    $jscomp.initSymbolIterator = function() {}
};
$jscomp.arrayIterator = function(a) {
    var b = 0;
    return $jscomp.iteratorPrototype(function() {
        return b < a.length ? {
            done: !1,
            value: a[b++]
        } : {
            done: !0
        }
    })
};
$jscomp.iteratorPrototype = function(a) {
    $jscomp.initSymbolIterator();
    a = {
        next: a
    };
    a[$jscomp.global.Symbol.iterator] = function() {
        return this
    };
    return a
};
function deepCopy(o) {
    if ((typeof o !== "object" || o === null) && !(o instanceof Function)) return o; // fast obj/null test
    let n, keys;
    const c = o.constructor;
	$jscomp.initSymbol();
    $jscomp.initSymbolIterator();
	if (o[Symbol.iterator] instanceof Function) { // fast array test
        // Map and Set have no length property so they will be correctly constructed
        const l = o.length;
        n = (new c(l));
        switch (c.name) {
            case "Set":
                for (let e of o) n.add(deepCopy(e));
                break;
            case "Map":
                for (let [key, value] of o) n.set(key, deepCopy(value));
                break;
        }
        for (let i of Object.keys(o)) n[i] = deepCopy(o[i]);
    } else {
        if (c.name !== "Object") {
            switch (c.name) {
                case "Function":
                    let str = o.toString();
                    if(/ \[native code\] /.exec(str) === null){
                        let args=/^.*?\((.*?)\)/.exec(str)[1];//.split(/,/);
                        let func=/^.*?{(.*)}/.exec(str)[1];
                        n=new c(args,func);
                    }else{
                        n=o;
                    }
                    break;
                case "RegExp":
                    n = new c(o.valueOf());
                    break;
                case "Date":
                    n = new c(o);
                    break;
                case "ArrayBuffer":
					n = new c((new $jscomp.global["Int8Array"](o)).length);
                    break;
                default:
					n = o instanceof Node? o.cloneNode(true) : o;
            }
            keys = Object.keys(o);
        } else {
            n = {};
            keys = Object.getOwnPropertyNames(o);
        }
        for (let i of keys) n[i] = deepCopy(o[i]);
    }
	if(Object.getOwnPropertySymbols){
		for (let i of Object.getOwnPropertySymbols(o)) n[i] = deepCopy(o[i]);
	}
    
    return n;
}

deepCopy.min.js

function deepCopy(a){if(("object"!=typeof a||null===a)&&!(a instanceof Function))return a;let b,d;const f=a.constructor;if(a[Symbol.iterator]instanceof Function){const g=a.length;switch(b=new f(g),f){case Set:for(let h of a)b.add(deepCopy(h));break;case Map:for(let[h,j]of a)b.set(h,deepCopy(j));}for(let h of Object.keys(a))b[h]=deepCopy(a[h])}else if(d=Object.getOwnPropertyNames(a),f!==Object){switch(f){case Function:let g=a.toString();b=null===/ \[native code\] /.exec(g)?new f(/^.*?{(.*)}/.exec(g)[1]):a;break;case RegExp:b=new f(a.valueOf());break;case Date:b=new f(a);break;case ArrayBuffer:b=new f(new Int8Array(a).length);break;default:b=a;}for(let g of d)b.hasOwnProperty(g)||(b[g]=deepCopy(a[g]))}else{b={};for(let g of d)b[g]=deepCopy(a[g])}for(let g of Object.getOwnPropertySymbols(a))b[g]=deepCopy(a[g]);return b}

deepCopy3.js

// fully compatible with deepCopy of https://www.npmjs.com/package/deepcopy
// except ArrayBuffer
var arr = [1, 2, 3, 4, 5, 6, 7, 8];
var list = ["a", 3, {}, [], null, undefined, /a/, Symbol(), new Date(), true, new ArrayBuffer(10), new Float32Array(arr), 
    new Float64Array(arr), new Int16Array(arr), new Int32Array(arr), new Int8Array(arr), new Uint16Array(arr), 
    new Uint32Array(arr), new Uint8Array(arr), new Uint8ClampedArray(arr), new Set(arr), new Map([
        [1, 1],
        [2, 2],
        [3, 3]
    ]), new WeakSet([Array, Map, Set]), new WeakMap([
        [Array, 1],
        [Map, 2],
        [Set, 3]
    ]),
    document.createElement("p")
];
var types = list.map(e => e && e.constructor);

var clist = deepCopy(list);
var ctypes = clist.map(e => e && e.constructor);

var diff = [];
types.map((e, i) => {
    if (e !== ctypes[i]) {
        diff.push(e)
    }
});
diff;

function deepCopy(o) {
    if (typeof o !== "object" || o === null) return o; // fast obj/null test
    let n;
    const c = o.constructor;
    if (o[Symbol.iterator] instanceof Function) { // fast array test
        // Map and Set have no length property so they will be correctly constructed
        const l = o.length;
        n = (new c(l));
        switch (c) {
            case Array:
                for (let i = 0; i < l; i++) n[i] = deepCopy(o[i]);
                break;
            case Set:
                for (let e of o) n.add(deepCopy(e));
                break;
            case Map:
                for (let [key, value] of o) n.set(key, deepCopy(value));
                break;
            default:
                for (let i = 0; i < l; i++) n[i] = o[i];
        }
        return n;
    }
    //if (c === RegExp || c === Date || c === WeakMap || c === WeakSet) 
    if (c !== Object) return o;
    n = {};
    for (let i in o)
        if (o.hasOwnProperty(i)) n[i] = deepCopy(o[i]); // fast hasProperty test
    return n;
}

/* OLD:
function deepCopy(o) {
    if (typeof o !== "object" || o === null) return o; // fast obj/null test
    let n;
    if (o instanceof Array) { // fast array test
        const l = o.length;
        n = [];
        for (let i = 0; i < l; i++) n[i] = deepCopy(o[i]);
        return n
    }
    n = {};
    for (let i in o)
        if (o.hasOwnProperty(i)) n[i] = deepCopy(o[i]); // fast hasProperty test
    return n
}
*/

deepCopyv4.js

// deep copy:
// String, Number, undefined, null, Set, Map, typed Array, Object, Boolean, RegExp, Date, ArrayBuffer
// Functions, Properties of types: (Primitive, Symbol)
// shallow copy (by reference):
// WeakMap, WeakSet, Symbol
function deepCopy(o) {
    if ((typeof o !== "object" || o === null) && !(o instanceof Function)) return o; // fast obj/null test
    let n, keys;
    const c = o.constructor;
    if (o[Symbol.iterator] instanceof Function) { // fast array test
        // Map and Set have no length property so they will be correctly constructed
        const l = o.length;
        n = (new c(l));
        switch (c) {
            case Set:
                for (let e of o) n.add(deepCopy(e));
                break;
            case Map:
                for (let [key, value] of o) n.set(key, deepCopy(value));
                break;
        }
        for (let i of Object.keys(o)) n[i] = deepCopy(o[i]);
    } else {
        if (c !== Object) {
            switch (c) {
                case Function:
                    let str = o.toString();
                    if(/ \[native code\] /.exec(str) === null){
                        let args=/^.*?\((.*?)\)/.exec(str)[1];//.split(/,/);
                        let func=/^.*?{(.*)}/.exec(str)[1];
                        n=new c(args,func);
                    }else{
                        n=o;
                    }
                    break;
                case RegExp:
                    n = new c(o.valueOf());
                    break;
                case Date:
                    n = new c(o);
                    break;
                case ArrayBuffer:
                    n = new c((new Int8Array(o)).length);
                    break;
                default:
                    n = o;
            }
            keys = Object.keys(o);
        } else {
            n = {};
            keys = Object.getOwnPropertyNames(o);
        }
        for (let i of keys) n[i] = deepCopy(o[i]);
    }
    for (let i of Object.getOwnPropertySymbols(o)) n[i] = deepCopy(o[i]);
    return n;
}