Support nested parent properties

index.js

@@ -1,6 +1,7 @@
 'use strict';
 var isArray = require('lodash.isarray');
 var assign = require('lodash.assign');
+var property = require('nested-property');
 
 var createTree = function(array, rootNodes, customID) {
   var tree = [];
@@ -25,7 +26,7 @@ var createTree = function(array, rootNodes, customID) {
 
 var groupByParents = function(array, options) {
   return array.reduce(function(prev, item) {
-    var parentID = item[options.parentProperty] || options.rootID;
+    var parentID = property.get(item, options.parentProperty) || options.rootID;
 
     if (parentID && prev.hasOwnProperty(parentID)) {
       prev[parentID].push(item);

license.md

@@ -1,4 +1,4 @@
-Copyright © 2016 sPhilipp Alferov.
+Copyright © 2016 Philipp Alferov.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

package.json

@@ -34,6 +34,7 @@
   "license": "MIT",
   "dependencies": {
     "lodash.assign": "^4.0.6",
-    "lodash.isarray": "^4.0.0"
+    "lodash.isarray": "^4.0.0",
+    "nested-property": "^0.0.7"
   }
 }

test/fixtures/expected-nested.fixture.js

@@ -0,0 +1,20 @@
+module.exports = [{
+  id: 1,
+  attributes: {
+    name: 'Parent',
+    parent_id: null
+  },
+  children: [{
+    id: 2,
+    attributes: {
+      name: 'Child One',
+      parent_id: 1
+    }
+  }, {
+    id: 3,
+    attributes: {
+      name: 'Child Two',
+      parent_id: 1
+    }
+  }]
+}];

test/fixtures/initial-nested.fixture.js

@@ -0,0 +1,19 @@
+module.exports = [{
+  id: 1,
+  attributes: {
+    name: 'Parent',
+    parent_id: null
+  }
+}, {
+  id: 2,
+  attributes: {
+    name: 'Child One',
+    parent_id: 1
+  }
+}, {
+  id: 3,
+  attributes: {
+    name: 'Child Two',
+    parent_id: 1
+  }
+}];

test/test.js

@@ -2,10 +2,13 @@
 var chai = require('chai');
 var expect = chai.expect;
 var toTree = require('../index.js');
+var initial = require('./fixtures/initial.fixture.js');
 var expected = require('./fixtures/expected.fixture.js');
 var customExpected = require('./fixtures/expected-custom.fixture.js');
 var customInitial = require('./fixtures/initial-custom.fixture.js');
-var initial = require('./fixtures/initial.fixture.js');
+var nestedInitial = require('./fixtures/initial-nested.fixture.js');
+var nestedExpected = require('./fixtures/expected-nested.fixture.js');
+
 var current;
 
 describe('array-to-tree', function() {
@@ -78,5 +81,13 @@ describe('array-to-tree', function() {
       expect(current)
         .to.be.deep.equal(customExpected);
     });
+    it('should work with nested parent id', function() {
+      current = toTree(nestedInitial, {
+        parentProperty: 'attributes.parent_id'
+      });
+
+      expect(current)
+        .to.be.deep.equal(nestedExpected);
+    });
   });
 });