Add clone and reach helpers.

clone.js

@@ -0,0 +1,52 @@
+/**
+* Clone object and all it's properties.
+* Works recursively.
+*
+* @param  {Object} obj  Object to clone.
+* @param  {Mixed}  seen For internal use only. Don't set.
+* @return {Object}      The clone.
+*/
+export const clone = (obj, seen) => {
+  if (typeof obj !== 'object' || obj === null) {
+    return obj;
+  }
+  seen = seen || new Map();
+  const lookup = seen.get(obj);
+  if (lookup) {
+    return lookup;
+  }
+  let newObj;
+  let cloneDeep = false;
+  if (!Array.isArray(obj)) {
+    if (obj instanceof Date) {
+      newObj = new Date(obj.getTime());
+    } else if (obj instanceof RegExp) {
+      newObj = new RegExp(obj);
+    } else {
+      const proto = Object.getPrototypeOf(obj);
+      if (proto && Object.isFrozen(obj)) {
+        newObj = obj;
+      } else {
+        newObj = Object.create(proto);
+        cloneDeep = true;
+      }
+    }
+  } else {
+    newObj = [];
+    cloneDeep = true;
+  }
+  seen.set(obj, newObj);
+  if (cloneDeep) {
+    const keys = Object.getOwnPropertyNames(obj);
+    for (let i = 0; i < keys.length; ++i) {
+      const key = keys[i];
+      const descriptor = Object.getOwnPropertyDescriptor(obj, key);
+      if (descriptor && (descriptor.get || descriptor.set)) {
+        Object.defineProperty(newObj, key, descriptor);
+      } else {
+        newObj[key] = this._clone(obj[key], seen);
+      }
+    }
+  }
+  return newObj;
+};