modularized random number generation logic

js/passwordGenerator.js

@@ -1,29 +1,35 @@
 var passwordGenerator = (function() {
-  return {
-    generatePassword: function (options) {
-      var uppercase = "ABCDEFGHIJKLMNOPQRSTUVWXTZ";
-      var lowercase = "abcdefghiklmnopqrstuvwxyz";
-      var numbers = "0123456789";
-      var punct = ".,-/#!$%^&*;:{}=-_`~()]";
-      var candidates = '';
-      if (options.includeUppercaseChars) {
-        candidates += uppercase;
-      }
-      if (options.includeLowercaseChars) {
-        candidates += lowercase;
-      }
-      if (options.includeNumbers) {
-        candidates += numbers;
-      }
-      if (options.includePunctuationChars) {
-        candidates += punct;
-      }
-      var result = "";
-      for (var i = 0; i < options.passwordLength; i++) {
-        var randomNum = Math.floor(Math.random() * candidates.length);
-        result += candidates.substring(randomNum, randomNum + 1);
-      }
-      return result;
+  var generateRandomNum = function (max) {
+    return Math.floor(Math.random() * max);
+  };
+
+  var generatePassword = function (options) {
+    var uppercase = "ABCDEFGHIJKLMNOPQRSTUVWXTZ";
+    var lowercase = "abcdefghiklmnopqrstuvwxyz";
+    var numbers = "0123456789";
+    var punct = ".,-/#!$%^&*;:{}=-_`~()]";
+    var candidates = '';
+    if (options.includeUppercaseChars) {
+      candidates += uppercase;
     }
+    if (options.includeLowercaseChars) {
+      candidates += lowercase;
+    }
+    if (options.includeNumbers) {
+      candidates += numbers;
+    }
+    if (options.includePunctuationChars) {
+      candidates += punct;
+    }
+    var result = "";
+    for (var i = 0; i < options.passwordLength; i++) {
+      var randomNum = generateRandomNum(candidates.length);
+      result += candidates.substring(randomNum, randomNum + 1);
+    }
+    return result;
+  };
+
+  return {
+    generatePassword: generatePassword
   };
 })();