moved debug fn out to own module, added tests

test/debug-test.js

@@ -0,0 +1,72 @@
+"use strict";
+var vows = require('vows')
+, assert = require('assert')
+, sandbox = require('sandboxed-module')
+, fakeConsole = {
+  error: function(format, label, message) {
+    this.logged = [ format, label, message ];
+  }
+}
+, globals = function(debugValue) {
+  return {
+    process: {
+      env: {
+        'NODE_DEBUG': debugValue
+      }
+    },
+    console: fakeConsole
+  };
+};
+
+vows.describe('../lib/debug').addBatch({
+  'when NODE_DEBUG is set to log4js': {
+    topic: function() {
+      var debug = sandbox.require(
+        '../lib/debug', 
+        { 'globals': globals('log4js') }
+      );
+
+      fakeConsole.logged = [];
+      debug('cheese')('biscuits');
+      return fakeConsole.logged;
+    },
+    'it should log to console.error': function(logged) {
+      assert.equal(logged[0], 'LOG4JS: (%s) %s');
+      assert.equal(logged[1], 'cheese');
+      assert.equal(logged[2], 'biscuits');
+    }
+  },
+
+  'when NODE_DEBUG is set to not log4js': {
+    topic: function() {
+      var debug = sandbox.require(
+        '../lib/debug',
+        { globals: globals('other_module') }
+      );
+
+      fakeConsole.logged = [];
+      debug('cheese')('biscuits');
+      return fakeConsole.logged;
+    },
+    'it should not log to console.error': function(logged) {
+      assert.equal(logged.length, 0);
+    }
+  },
+
+  'when NODE_DEBUG is not set': {
+    topic: function() {
+      var debug = sandbox.require(
+        '../lib/debug',
+        { globals: globals(null) }
+      );
+
+      fakeConsole.logged = [];
+      debug('cheese')('biscuits');
+      return fakeConsole.logged;
+    },
+    'it should not log to console.error': function(logged) {
+      assert.equal(logged.length, 0);
+    }
+  }
+
+}).exportTo(module);