Add ability to run spec files in random order

lib/jasmine-node/array-shuffler.js

@@ -0,0 +1,39 @@
+var previous;
+
+// MINSTD Lehmer random number generator
+var MODULUS = Math.pow( 2, 31 ) - 1, MULTIPLIER = 48271, INCREMENT = 0;
+var randInt = function() {
+  return previous = ( previous * MULTIPLIER + INCREMENT ) % MODULUS;
+};
+
+var rand = function( range ) {
+  if( range == 0 ) {
+    return 0;
+  }
+
+  // Doesn't provide a very uniform distribution - but good enough
+  // for shuffling tests
+  return randInt() % range;
+};
+
+exports.seedRandom = function( seed ) {
+  var moduloSeed;
+  if( typeof seed != 'undefined' ) {
+    moduloSeed = seed % MODULUS;
+  } else {
+    moduloSeed = Math.floor( Math.random() * ( Math.pow( 2, 31 ) - 2 ) );
+  }
+  console.log( 'Shuffling tests with seed ' + moduloSeed );
+  previous = moduloSeed;
+};
+
+exports.shuffle = function( array ) {
+  // Fisher-Yates shuffle, as implemented by Durstenfeld
+  for( var i = array.length - 1; i > 0; i-- ) {
+    var swapIndex = rand( i - 1 );
+    var temp = array[ swapIndex ];
+    array[ swapIndex ] = array[ i ];
+    array[ i ] = temp;
+  }
+};
+

lib/jasmine-node/cli.js

@@ -33,6 +33,8 @@ var useRequireJs = false;
 var extensions = "js";
 var match = '.';
 var matchall = false;
+var randomize = false;
+var randomSeed;
 var autotest = false;
 var useHelpers = true;
 var forceExit = false;
@@ -82,6 +84,13 @@ while(args.length) {
     case '--matchall':
       matchall = true;
       break;
+    case '--randomize':
+        randomize = true;
+        break;
+    case '--seed':
+        randomize = true;
+        randomSeed = parseInt( args.shift(), 10 );
+        break;
     case '--junitreport':
         junitreport.report = true;
         break;
@@ -240,6 +249,8 @@ var options = {
   teamcity:     teamcity,
   useRequireJs: useRequireJs,
   regExpSpec:   regExpSpec,
+  randomize:    randomize,
+  randomSeed:   randomSeed,
   junitreport:  junitreport,
   includeStackTrace: includeStackTrace,
   growl:        growl
@@ -259,6 +270,8 @@ function help(){
   , '  --noColor          - do not use color coding for output'
   , '  -m, --match REGEXP - load only specs containing "REGEXPspec"'
   , '  --matchall         - relax requirement of "spec" in spec file names'
+  , '  --randomize        - shuffle the list of spec files before running'
+  , '  --seed SEED        - shuffle the list of spec files using the supplied seed'
   , '  --verbose          - print extra information per each test run'
   , '  --coffee           - load coffee-script which allows execution .coffee files'
   , '  --junitreport      - export tests results as junitreport xml format'

lib/jasmine-node/index.js

@@ -92,6 +92,8 @@ jasmine.executeSpecsInFolder = function(options){
   var useRequireJs = options['useRequireJs'];
   var matcher =      options['regExpSpec'];
   var junitreport = options['junitreport'];
+  var randomize =    options['randomize'];
+  var randomSeed =   options['randomSeed'];
   var includeStackTrace = options['includeStackTrace'];
   var growl = options['growl'];
 
@@ -152,6 +154,19 @@ jasmine.executeSpecsInFolder = function(options){
   } else {
     var specsList = specs.getSpecs();
 
+    if (randomize) {
+      var arrayShuffler = require('./array-shuffler');
+      arrayShuffler.seedRandom(randomSeed);
+      arrayShuffler.shuffle(specsList);
+
+      if (isVerbose) {
+        console.log('Executing tests in this order:');
+        for( var i = 0; i < specsList.length; i++ ) {
+          console.log( specsList[i].filename() );
+        }
+      }
+    }
+
     for (var i = 0, len = specsList.length; i < len; ++i) {
       var filename = specsList[i];
       delete require.cache[filename.path()];