add deepFreeze

test/deepFreeze/deepFreeze.js

@@ -0,0 +1,17 @@
+const deepFreeze = obj => {
+  Object.freeze(obj);
+
+  Object.getOwnPropertyNames(obj).forEach(function(prop) {
+    if (
+      obj.hasOwnProperty(prop) &&
+      obj[prop] !== null &&
+      (typeof obj[prop] === 'object' || typeof obj[prop] === 'function') &&
+      !Object.isFrozen(obj[prop])
+    ) {
+      deepFreeze(obj[prop]);
+    }
+  });
+
+  return obj;
+};
+module.exports = deepFreeze;

test/deepFreeze/deepFreeze.test.js

@@ -0,0 +1,6 @@
+const expect = require('expect');
+const deepFreeze = require('./deepFreeze.js');
+
+test('deepFreeze is a Function', () => {
+  expect(deepFreeze).toBeInstanceOf(Function);
+});