Merge pull request #1147 from cowboyd/one-random-number-generator-per-faker

Give each faker instance its own random number generator

7 files changed, 41 insertions, 39 deletions

diff --git a/lib/datatype.js b/lib/datatype.js
index d2ec9ad2..02ea3759 100644
--- a/lib/datatype.js
+++ b/lib/datatype.js
@@ -1,5 +1,3 @@
-var mersenne = require('../vendor/mersenne');

-

 /**

  *

  * @namespace faker.datatype

@@ -7,10 +5,10 @@ var mersenne = require('../vendor/mersenne');
 function Datatype (faker, seed) {

   // Use a user provided seed if it is an array or number

   if (Array.isArray(seed) && seed.length) {

-    mersenne.seed_array(seed);

+    faker.mersenne.seed_array(seed);

   }

   else if(!isNaN(seed)) {

-    mersenne.seed(seed);

+    faker.mersenne.seed(seed);

   }

 

   /**

@@ -47,7 +45,7 @@ function Datatype (faker, seed) {
     }

 

     var randomNumber = Math.floor(

-      mersenne.rand(max / options.precision, options.min / options.precision));

+      faker.mersenne.rand(max / options.precision, options.min / options.precision));

     // Workaround problem in Float point arithmetics for e.g. 6681493 / 0.01

     randomNumber = randomNumber / (1 / options.precision);

 

diff --git a/lib/index.js b/lib/index.js
index f76a581e..a80580bd 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -92,6 +92,9 @@ function Faker (opts) {
   var Unique = require('./unique');
   self.unique = new Unique(self).unique;
 
+  var Mersenne = require('./mersenne');
+  self.mersenne = new Mersenne();
+
   var Random = require('./random');
   self.random = new Random(self);
 
diff --git a/lib/mersenne.js b/lib/mersenne.js
new file mode 100644
index 00000000..722ebc46
--- /dev/null
+++ b/lib/mersenne.js
@@ -0,0 +1,31 @@
+var Gen = require('../vendor/mersenne').MersenneTwister19937;
+
+function Mersenne() {
+  var gen = new Gen();
+  gen.init_genrand((new Date).getTime() % 1000000000);
+
+  this.rand = function(max, min) {
+    if (max === undefined)
+    {
+      min = 0;
+      max = 32768;
+    }
+    return Math.floor(gen.genrand_real2() * (max - min) + min);
+  }
+  this.seed = function(S) {
+    if (typeof(S) != 'number')
+    {
+      throw new Error("seed(S) must take numeric argument; is " + typeof(S));
+    }
+    gen.init_genrand(S);
+  }
+  this.seed_array = function(A) {
+    if (typeof(A) != 'object')
+    {
+      throw new Error("seed_array(A) must take array of numbers; is " + typeof(A));
+    }
+    gen.init_by_array(A, A.length);
+  }
+}
+
+module.exports = Mersenne;
diff --git a/lib/random.js b/lib/random.js
index 4c2daaac..4443c555 100644
--- a/lib/random.js
+++ b/lib/random.js
@@ -1,5 +1,3 @@
-var mersenne = require('../vendor/mersenne');
-
 /**
  * Method to reduce array of characters
  * @param arr existing array of characters
@@ -22,10 +20,10 @@ var arrayRemove = function (arr, values) {
 function Random (faker, seed) {
   // Use a user provided seed if it is an array or number
   if (Array.isArray(seed) && seed.length) {
-    mersenne.seed_array(seed);
+    faker.mersenne.seed_array(seed);
   }
   else if(!isNaN(seed)) {
-    mersenne.seed(seed);
+    faker.mersenne.seed(seed);
   }
 
   /**
diff --git a/test/random.unit.js b/test/random.unit.js
index 147d7dbb..b45d347d 100644
--- a/test/random.unit.js
+++ b/test/random.unit.js
@@ -3,7 +3,7 @@ if (typeof module !== 'undefined') {
   var sinon = require('sinon');
   var _ = require('lodash');
   var faker = require('../index');
-  var mersenne = require('../vendor/mersenne');
+  var mersenne = new (require('../lib/mersenne'));
 }
 
 
diff --git a/test/support/function-helpers.js b/test/support/function-helpers.js
index 326da61a..5411ac71 100644
--- a/test/support/function-helpers.js
+++ b/test/support/function-helpers.js
@@ -9,7 +9,7 @@ var functionHelpers = {};
 module.exports = functionHelpers;
 
 
-var IGNORED_MODULES = ['locales', 'locale', 'localeFallback', 'definitions', 'fake', 'helpers'];
+var IGNORED_MODULES = ['locales', 'locale', 'localeFallback', 'definitions', 'fake', 'helpers', 'mersenne'];
 var IGNORED_METHODS = {
     system: ['directoryPath', 'filePath'] // these are TODOs
 };
diff --git a/vendor/mersenne.js b/vendor/mersenne.js
index edc4743c..4d9d0322 100644
--- a/vendor/mersenne.js
+++ b/vendor/mersenne.js
@@ -256,31 +256,3 @@ function MersenneTwister19937()
 
 //  Export the twister class
 exports.MersenneTwister19937 = MersenneTwister19937;
-
-//  Export a simplified function to generate random numbers
-var gen = new MersenneTwister19937;
-gen.init_genrand((new Date).getTime() % 1000000000);
-
-// Added max, min range functionality, Marak Squires Sept 11 2014
-exports.rand = function(max, min) {
-  if (max === undefined)
-  {
-    min = 0;
-    max = 32768;
-  }
-  return Math.floor(gen.genrand_real2() * (max - min) + min);
-}
-exports.seed = function(S) {
-  if (typeof(S) != 'number')
-  {
-    throw new Error("seed(S) must take numeric argument; is " + typeof(S));
-  }
-  gen.init_genrand(S);
-}
-exports.seed_array = function(A) {
-  if (typeof(A) != 'object')
-  {
-    throw new Error("seed_array(A) must take array of numbers; is " + typeof(A));
-  }
-  gen.init_by_array(A, A.length);
-}
\ No newline at end of file