Expose validation metadata

The new Validatable.validations mixin method returns the validations as
an object
indexed by property name.

lib/validations.js

@@ -1,4 +1,6 @@
 var util = require('util');
+var extend = util._extend;
+
 /*!
  * Module exports
  */
@@ -23,6 +25,18 @@ exports.Validatable = Validatable;
 function Validatable() {
 }
 
+Validatable.validations = function() {
+  var validations = {};
+  (this._validations || []).forEach(function(v) {
+    var key = v[0], validation = v[1], options = v[3];
+    var copy = extend({}, validation);
+    copy.options = options || {};
+    validations[key] = validations[key] || [];
+    validations[key].push(copy);
+  });
+  return validations;
+};
+
 /**
  * Validate presence of one or more specified properties. 
  * Requires a model to include a property to be considered valid; fails when validated field is blank.

test/validations.test.js

@@ -130,6 +130,14 @@ describe('validations', function () {
           done();
         });
       });
+      
+      it('should return validation metadata', function() {
+        var expected = {name:[{validation: 'presence', options: {}}]};
+        delete User._validations;
+        User.validatesPresenceOf('name');
+        var validations = User.validations();
+        validations.should.eql(expected);
+      });
     });
   });