Implement `findOrCreate` for memory connector

lib/connectors/memory.js

@@ -189,7 +189,7 @@ Memory.prototype.define = function defineModel(definition) {
   if(!this.collection(m)) this.initCollection(m);
 };
 
-Memory.prototype.create = function create(model, data, options, callback) {
+Memory.prototype._createSync = function(model, data, fn) {
   // FIXME: [rfeng] We need to generate unique ids based on the id type
   // FIXME: [rfeng] We don't support composite ids yet
   var currentId = this.collectionSeq(model);
@@ -207,18 +207,27 @@ Memory.prototype.create = function create(model, data, options, callback) {
   var idName = this.idName(model);
   id = (props[idName] && props[idName].type && props[idName].type(id)) || id;
   this.setIdValue(model, data, id);
-  if(!this.collection(model)) {
+  if (!this.collection(model)) {
     this.collection(model, {});
   }
 
-  if (this.collection(model)[id]) {
+  if (this.collection(model)[id])
-    return process.nextTick(function() {
+    return fn(new Error('Duplicate entry for ' + model + '.' + idName));
-      callback(new Error('Duplicate entry for ' + model + '.' + idName));
-    });
-  }
 
   this.collection(model)[id] = serialize(data);
-  this.saveToFile(id, callback);
+  fn(null, id);
+};
+
+Memory.prototype.create = function create(model, data, options, callback) {
+  var self = this;
+  this._createSync(model, data, function(err, id) {
+    if (err) {
+      return process.nextTick(function() {
+        callback(err);
+      });
+    };
+    self.saveToFile(id, callback);
+  });
 };
 
 Memory.prototype.updateOrCreate = function (model, data, options, callback) {
@@ -237,6 +246,36 @@ Memory.prototype.updateOrCreate = function (model, data, options, callback) {
   });
 };
 
+Memory.prototype.findOrCreate = function(model, filter, data, callback) {
+  var self = this;
+  var nodes = self._findAllSkippingIncludes(model, filter);
+  var found = nodes[0];
+
+  if(!found) {
+    // Calling _createSync to update the collection in a sync way and to guarantee to create it in the same turn of even loop
+    return self._createSync(model, data, function(err, id) {
+      if (err) return callback(err);
+      self.saveToFile(id, function(err, id) {
+        self.setIdValue(model, data, id);
+        callback(err, data, true);
+      });
+    });
+  }
+
+  if (!filter || !filter.include) {
+    return process.nextTick(function() {
+      callback(null, found, false);
+    });
+  }
+   
+  self._models[model].model.include(nodes[0], filter.include, {}, function(err, nodes) {
+    process.nextTick(function() {
+      if (err) return callback(err);
+      callback(null, nodes[0], false);
+    });
+  });
+};
+
 Memory.prototype.save = function save(model, data, options, callback) {
   var self = this;
   var id = this.getIdValue(model, data);
@@ -312,8 +351,7 @@ function getValue(obj, path) {
   return val;
 }
 
-Memory.prototype.all = function all(model, filter, options, callback) {
+Memory.prototype._findAllSkippingIncludes = function(model, filter) {
-  var self = this;
   var nodes = Object.keys(this.collection(model)).map(function (key) {
     return this.fromDb(model, this.collection(model)[key]);
   }.bind(this));
@@ -364,15 +402,8 @@ Memory.prototype.all = function all(model, filter, options, callback) {
     var limit = filter.limit || nodes.length;
     nodes = nodes.slice(skip, skip + limit);
   }
-
+  return nodes;
-  process.nextTick(function () {
+  
-    if (filter && filter.include) {
-      self._models[model].model.include(nodes, filter.include, options, callback);
-    } else {
-      callback(null, nodes);
-    }
-  });
-
   function sorting(a, b) {
     var undefinedA, undefinedB;
 
@@ -393,6 +424,19 @@ Memory.prototype.all = function all(model, filter, options, callback) {
   }
 };
 
+Memory.prototype.all = function all(model, filter, options, callback) {
+  var self = this;
+  var nodes = self._findAllSkippingIncludes(model, filter);
+
+  process.nextTick(function() {
+    if (filter && filter.include) {
+      self._models[model].model.include(nodes, filter.include, options, callback);
+    } else {
+      callback(null, nodes);
+    }
+  });
+};
+
 function applyFilter(filter) {
   var where = filter.where;
   if (typeof where === 'function') {

test/memory.test.js

@@ -345,7 +345,6 @@ describe('Memory connector', function() {
         }
       }, function (err, users) {
         should.not.exist(err);
-        console.log(users);
         users.length.should.be.equal(5);
         done();
       });
@@ -695,6 +694,38 @@ describe('Memory connector', function() {
 
   });
 
+  describe('findOrCreate', function() {
+    var ds, Cars;
+    before(function() {
+      ds = new DataSource({connector: 'memory'});
+      Cars = ds.define('Cars', {
+        color: String
+      });
+    });
+
+    it('should create a specific object once and in the subsequent calls it should find it', function(done) {
+      var creationNum = 0;
+      async.times(100, function(n, next) {
+        var initialData = {color: 'white'};
+        var query = {'where': initialData};
+        Cars.findOrCreate(query, initialData, function(err, car, created) {
+          if (created) creationNum++;
+          next(err, car);
+        });
+      }, function(err, cars) {
+        if (err) done(err);
+        Cars.find(function(err, data) {
+          if (err) done(err);
+          data.length.should.equal(1);
+          data[0].color.should.equal('white');
+          creationNum.should.equal(1);
+          done();
+        });
+      });
+    });
+  });
+
+
   describe('automigrate when NO models are attached', function() {
     var ds;
     beforeEach(function() {