Add getOrCreate method + proper testing.

lib/dao-factory.js

@@ -194,6 +194,34 @@ module.exports = (function() {
     return this.build(values).save(fields)
   }
 
+  DAOFactory.prototype.getOrCreate = function (params, defaults) {
+    var self = this;
+
+    return new Utils.CustomEventEmitter(function (emitter) {
+      self.find({
+        where: params
+      }).success(function (instance) {
+        if (instance === null) {
+          for (var attrname in defaults) {
+            params[attrname] = defaults[attrname];
+          }
+
+          self.create(params)
+	    .success(function (instance) {
+              emitter.emit('success', instance)
+            })
+	    .error( function (erro) {
+              emitter.emit('error', error)
+            });
+        } else {
+          emitter.emit('success', instance)
+        }
+      }).error(function (error) {
+        emitter.emit('error', error)
+      });
+    }).run()
+  }
+
   DAOFactory.prototype.__defineGetter__('primaryKeys', function() {
     var result = {}
     Utils._.each(this.attributes, function(dataTypeString, attributeName) {

spec/dao-factory.spec.js

@@ -28,6 +28,58 @@ dialects.forEach(function(dialect) {
       })
     })
 
+    describe('getOrCreate', function () {
+      it("Returns instace if already existent. Single find field.", function (done) {
+        var self = this,
+          data = {
+            username: 'Username'
+          };
+
+        this.User.create(data).success(function (user) {
+          self.User.getOrCreate({
+            username: user.username
+          }).success(function (_user) {
+            expect(_user.id).toEqual(user.id)
+            expect(_user.username).toEqual('Username')
+            done()
+          })
+        })
+      })
+
+      it("Returns instace if already existent. Multiple find fields.", function (done) {
+        var self = this,
+          data = {
+            username: 'Username',
+            data: 'ThisIsData'
+          };
+
+        this.User.create(data).success(function (user) {
+          self.User.getOrCreate(data).success(function (_user) {
+            expect(_user.id).toEqual(user.id)
+            expect(_user.username).toEqual('Username')
+            expect(_user.data).toEqual('ThisIsData')
+            done()
+          })
+        })
+      })
+
+      it("Creates new instance with default value.", function (done) {
+        var self = this,
+          data = {
+            username: 'Username'
+          },
+          default_values = {
+            data: 'ThisIsData'
+          };
+
+        this.User.getOrCreate(data, default_values).success(function (user) {
+          expect(user.username).toEqual('Username')
+          expect(user.data).toEqual('ThisIsData')
+          done()
+        })
+      })
+    })
+
     describe('create', function() {
       it('should only store the values passed in the witelist', function(done) {
         var self = this