added keys w/ tests

keys.js

@@ -0,0 +1,15 @@
+/**
+ * @module object-loops/keys
+ */
+
+/**
+ * Equivalent to `Object.keys`. Implemented specifically for chain.
+ * @function module:object-loops/keys
+ * @param {object} [obj] - object to get hasOwnProperty enumerable keys from
+ * @returns {array} keys
+ */
+module.exports = keys
+
+function keys (obj) {
+  return Object.keys(obj)
+}

test/test-keys.js

@@ -0,0 +1,43 @@
+var Code = require('code')
+var Lab = require('lab')
+var lab = exports.lab = Lab.script()
+
+var describe = lab.describe
+var it = lab.it
+var before = lab.before
+var after = lab.after
+var expect = Code.expect
+
+var keys = require('../keys')
+
+describe('keys', function () {
+  function Person (name) {
+    this.name = name
+  }
+  Person.prototype.getName = function () {
+    return this.name
+  }
+
+  describe('prototype', function () {
+    before(function (done) {
+      require('../index')()
+      done()
+    })
+    after(require('./fixtures/reset-object-prototype'))
+    it('should get all direct enumerables keys from object', function (done) {
+      var objKeys = new Person('hey').keys()
+      // assertions
+      expect(objKeys).to.deep.equal(['name'])
+      done()
+    })
+  })
+
+  describe('require', function () {
+    it('should get all direct enumerables keys from object', function (done) {
+      var objKeys = keys(new Person('hey'))
+      // assertions
+      expect(objKeys).to.deep.equal(['name'])
+      done()
+    })
+  })
+})