RunKit + npm: @createvibe/proxyobserver

// reverse changes to an object const proxyobserver = require("@createvibe/proxyobserver") const data = {initializing: true}; const reverse = []; const proxy = proxyobserver(data, function() { const chain = Array.prototype.slice.call(arguments); const root = chain[0]; const leaf = chain[chain.length - 1]; const path = chain.map(link => link.prop); const link = {chain: chain.slice(), root, leaf, path}; leaf.value = leaf.value && JSON.parse(JSON.stringify(leaf.value)) || leaf.value; leaf.oldValue = leaf.oldValue && JSON.parse(JSON.stringify(leaf.oldValue)) || leaf.oldValue; reverse.push(() => { if (leaf.oldValue === undefined) { return Reflect.deleteProperty(leaf.target, leaf.prop); } let node; let reference = data; const chain = link.chain.slice(0, -1); while (node = chain.shift()) { const { prop, oldValue } = node; if (!(prop in reference)) { Reflect.defineProperty(reference, prop, { value: oldValue, enumerable: true, configurable: true, writable: true }); } reference = reference[prop]; } if (leaf.prop in reference) { return Reflect.set(reference, leaf.prop, leaf.oldValue, leaf.receiver); } Reflect.defineProperty(reference, leaf.prop, { value: leaf.oldValue, enumerable: true, configurable: true, writable: true }); }); }); // remove the initializing flag delete proxy.initializing; // add data to the object proxy.one = 'test'; proxy.two = [1,2,3]; proxy.two.splice(0,1,5,8,9); proxy.three = { nested: [4,5,6], data: {value: 'test'} }; // modify data in the object proxy.one = 'modified'; proxy.two[1] = 'test'; proxy.two = ['array', 'change']; proxy.two.push('stuff'); proxy.two = null; proxy.two = undefined; proxy.two = 'test'; proxy.two = undefined; proxy.two = undefined; proxy.two = 'foo'; proxy.two = undefined; delete proxy.two; proxy.three.data.value = 'modified'; proxy.three.nested.push(7); proxy.three.nested.splice(0,0,3); // delete data delete proxy.one; console.log('the updated data', JSON.stringify(data)); // now reverse the last change reverse.pop().call(null); // now reverse the rest of the changes! while (reverse.length !== 0) { reverse.pop().call(null); } // notice the object is exactly how it was when we initialized it console.log('the reset data', JSON.stringify(data));