Add color stickiness and rollback to an incremental iteration on colo…

…r available

src/debug.js

@@ -34,6 +34,18 @@ exports.formatters = {};
 
 var prevTime;
 
+/**
+* Incremental cursor to have better color distribution
+*/
+
+var prevColor = 0;
+
+/**
+* Colors stickiness
+*/
+
+var previousColors = {};
+
 /**
  * Select a color.
  * @param {String} namespace
@@ -42,14 +54,14 @@ var prevTime;
  */
 
 function selectColor(namespace) {
-  var hash = 0, i;
-
-  for (i in namespace) {
-    hash  = ((hash << 5) - hash) + namespace.charCodeAt(i);
-    hash |= 0; // Convert to 32bit integer
+  var previousColor = previousColors[namespace];
+  if (previousColor !== undefined) {
+    return previousColor;
   }
 
-  return exports.colors[Math.abs(hash) % exports.colors.length];
+  previousColors[namespace] = exports.colors[prevColor++ % exports.colors.length];
+
+  return previousColors[namespace];
 }
 
 /**

test/debug_spec.js

@@ -6,11 +6,11 @@ var chai
   , debug
   , sinon
   , sinonChai;
-  
+
 if (typeof module !== 'undefined') {
   chai = require('chai');
   expect = chai.expect;
-  
+
   debug = require('../src/index');
   sinon = require('sinon');
   sinonChai = require("sinon-chai");
@@ -20,28 +20,28 @@ if (typeof module !== 'undefined') {
 
 describe('debug', function () {
   var log = debug('test');
-  
+
   log.log = sinon.stub();
-  
+
   it('passes a basic sanity check', function () {
     expect(log('hello world')).to.not.throw;
   });
 
   context('with log function', function () {
-        
+
     beforeEach(function () {
       debug.enable('test');
       log = debug('test');
     });
-  
+
     it('uses it', function () {
       log.log = sinon.stub();
       log('using custom log function');
 
       expect(log.log).to.have.been.calledOnce;
     });
   });
-  
+
   describe('custom functions', function () {
     var log;
 
@@ -59,4 +59,17 @@ describe('debug', function () {
       });
     });
   });
+
+  describe('colors stickiness', function () {
+    beforeEach(function () {
+      debug.enable('test');
+    });
+
+    it('should return same color for same namespace', function () {
+      var log1 = debug('test');
+      var log2 = debug('test');
+
+      expect(log1.color).to.equal(log2.color);
+    });
+  });
 });