Convert random generator to es6 and add some specs for it directly

lib/key_generators/random.js

@@ -1,19 +1,20 @@
-var RandomKeyGenerator = function(options) {
-  if (!options) {
-    options = {};
-  }
-  this.keyspace = options.keyspace || 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
-};
+module.exports = class RandomKeyGenerator {
 
-// Generate a random key
-RandomKeyGenerator.prototype.createKey = function(keyLength) {
+  // Initialize a new generator with the given keySpace
+  constructor(options = {}) {
+    this.keyspace = options.keyspace || 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
+  }
+
+  // Generate a key of the given length
+  createKey(keyLength) {
     var text = '';
-  var index;
+
     for (var i = 0; i < keyLength; i++) {
-    index = Math.floor(Math.random() * this.keyspace.length);
+      const index = Math.floor(Math.random() * this.keyspace.length);
       text += this.keyspace.charAt(index);
     }
-  return text;
-};
 
-module.exports = RandomKeyGenerator;
+    return text;
+  }
+
+};

package.json

@@ -46,6 +46,6 @@
   },
   "scripts": {
     "start": "node server.js",
-    "test": "mocha"
+    "test": "mocha --recursive"
   }
 }

test/key_generators/random_spec.js

@@ -0,0 +1,19 @@
+/* global describe, it */
+
+const assert = require('assert');
+
+const Generator = require('../../lib/key_generators/random');
+
+describe('RandomKeyGenerator', function() {
+  describe('randomKey', function() {
+    it('should return a key of the proper length', function() {
+      var gen = new Generator();
+      assert.equal(6, gen.createKey(6).length);
+    });
+
+    it('should use a key from the given keyset if given', () => {
+      var gen = new Generator({keyspace: 'A'});
+      assert.equal('AAAAAA', gen.createKey(6));
+    });
+  });
+});