add deepFreeze

snippets/deepFreeze.md

@@ -0,0 +1,38 @@
+### deepFreeze
+
+Deep freezes an object.
+
+Calls `Object.freeze(obj)` recursively on all unfrozen properties of obj that are `typeof` function or object.
+
+```js
+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;
+};
+```
+
+```js
+'use strict';
+
+const a = Object.freeze([1, [2, 3]]);
+
+a[0] = 3; // not allowed
+a[1][0] = 4; // allowed but shouldn't be
+
+const b = deepFreeze([1, [2, 3]]);
+
+b[0] = 3; // not allowed
+b[1][0] = 4; // not allowed as well
+```

tag_database

@@ -48,6 +48,7 @@ debounce:function
 decapitalize:string,array
 deepClone:object,recursion
 deepFlatten:array,recursion
+deepFreeze:object,recursion
 defaults:object
 defer:function
 degreesToRads:math

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);
+});