Merge branch 'master' of https://github.com/taoqf/array-to-tree into taoqf-master

Author: Philipp Alferov

index.d.ts

@@ -0,0 +1,16 @@
+export = arrayToTree;
+
+declare function arrayToTree<T>(data: T[], options?: Partial<arrayToTree.Options>): Array<arrayToTree.Tree<T>>;
+
+declare namespace arrayToTree {
+	interface Options {
+		childrenProperty: string;
+		parentProperty: string;
+		customID: string;
+		rootID: string;
+	}
+
+	type Tree<T> = T & {
+		children?: Array<Tree<T>>;
+	};
+}

index.js

@@ -47,6 +47,23 @@ var groupByParents = function(array, options) {
   }, {});
 };
 
+function isObject(o) {
+  return Object.prototype.toString.call(o) === '[object Object]';
+}
+
+function deepClone(data) {
+  if (Array.isArray(data)) {
+    return data.map(deepClone);
+  } else if (isObject(data)) {
+    return Object.keys(data).reduce(function(o, k) {
+      o[k] = deepClone(data[k]);
+      return o;
+    }, {});
+  } else {
+    return data;
+  }
+}
+
 /**
  * arrayToTree
  * Convert a plain array of nodes (with pointers to parent nodes) to a nested
@@ -82,7 +99,7 @@ module.exports = function arrayToTree(data, options) {
     throw new TypeError('Expected an object but got an invalid argument');
   }
 
-  var grouped = groupByParents(data.slice(), options);
+  var grouped = groupByParents(deepClone(data), options);
   return createTree(
     grouped,
     grouped[options.rootID],