prototype-clone

Like Object.assign(), but all simple objects will be deep-copied into derived objects.

Install

npm install prototype-clone

API

.clone = function (source1 /*, source2 ... */);     //module default

.assign = function (target, source1 /*, source2 ... */);
.copySingle = function (target, source /*, refMap */);
.createRef = function (o, refMap);

Usage

var prototype_clone = require("prototype-clone");
var prototype_stringify = require("prototype-stringify");   //tool for debug

var a = { b: 1, c: { d: 2 }, e: { f: 3 } };
var a_s0 = JSON.stringify(a);

//clone 1 object
var aa = prototype_clone(a);

assert(aa.b === 1 && aa.c.d === 2 && aa.e.f === 3);		//value from prototype

assert(JSON.stringify(aa) === '{"c":{},"e":{}}');	//clone as void
assert(prototype_stringify(aa) === '{"b":1,"c":{"d":2},"e":{"f":3}}');

aa.c.dd = 22;
aa.e.f = 33;
aa.e.ff = 333;
aa.gg = 44;

assert(JSON.stringify(aa) === '{"c":{"dd":22},"e":{"f":33,"ff":333},"gg":44}');
assert(prototype_stringify(aa) === '{"b":1,"c":{"d":2,"dd":22},"e":{"f":33,"ff":333},"gg":44}');

//clone from 2 objects
var aaa = prototype_clone(a, { c: { dd: 22 }, e: { f: 33, ff: 333 }, gg: 44 });
assert(JSON.stringify(aaa) === '{"c":{"dd":22},"e":{"f":33,"ff":333},"gg":44}');
assert(prototype_stringify(aaa) === '{"b":1,"c":{"d":2,"dd":22},"e":{"f":33,"ff":333},"gg":44}');

//source is unchanged
assert(a_s0 === JSON.stringify(a));

//change source prototype
a.h = 5;

assert(aa.h === 5 && aaa.h === 5);		//value from prototype

//unchanged owned property
assert(JSON.stringify(aa) === '{"c":{"dd":22},"e":{"f":33,"ff":333},"gg":44}');
//changed from prototype
assert(prototype_stringify(aa) === '{"b":1,"c":{"d":2,"dd":22},"e":{"f":33,"ff":333},"gg":44,"h":5}');
//unchanged owned property
assert(JSON.stringify(aaa) === '{"c":{"dd":22},"e":{"f":33,"ff":333},"gg":44}');
//changed from prototype
assert(prototype_stringify(aaa) === '{"b":1,"c":{"d":2,"dd":22},"e":{"f":33,"ff":333},"gg":44,"h":5}');