Fix id type issue for update

https://github.com/strongloop/loopback/issues/1058

lib/connectors/memory.js

@@ -573,6 +573,9 @@ Memory.prototype.update =
     async.each(ids, function (id, done) {
       var inst = self.fromDb(model, cache[id]);
       if (!filter || filter(inst)) {
+        // The id value from the cache is string
+        // Get the real id from the inst
+        id = self.getIdValue(model, inst);
         self.updateAttributes(model, id, data, done);
       } else {
         process.nextTick(done);

test/memory.test.js

@@ -27,22 +27,37 @@ describe('Memory connector', function () {
     });
   });
 
-  it('should save to a json file', function (done) {
+  describe('with file', function() {
+    function createUserModel() {
       var ds = new DataSource({
         connector: 'memory',
         file: file
       });
 
       var User = ds.createModel('User', {
+        id: {
+          type: Number,
+          id: true,
+          generated: true
+        },
         name: String,
         bio: String,
         approved: Boolean,
         joinedAt: Date,
         age: Number
       });
+      return User;
+    }
 
-    var count = 0;
+    var User;
     var ids = [];
+
+    before(function() {
+      User = createUserModel();
+    });
+
+    it('should persist create', function(done) {
+      var count = 0;
       async.eachSeries(['John1', 'John2', 'John3'], function(item, cb) {
         User.create({name: item}, function(err, result) {
           ids.push(result.id);
@@ -52,40 +67,64 @@ describe('Memory connector', function () {
             cb(err);
           });
         });
-    }, function (err, results) {
+      }, done);
+    });
+
+    it('should persist delete', function(done) {
       // Now try to delete one
       User.deleteById(ids[0], function(err) {
+        if (err) {
+          return done(err);
+        }
         readModels(function(err, json) {
+          if (err) {
+            return done(err);
+          }
           assert.equal(Object.keys(json.models.User).length, 2);
-          User.upsert({id: ids[1], name: 'John'}, function(err, result) {
-            readModels(function (err, json) {
-              assert.equal(Object.keys(json.models.User).length, 2);
-              var user = JSON.parse(json.models.User[ids[1]]);
-              assert.equal(user.name, 'John');
           done();
         });
       });
     });
+
+    it('should persist upsert', function(done) {
+      User.upsert({id: ids[1], name: 'John'}, function(err, result) {
+        if (err) {
+          return done(err);
+        }
+        readModels(function(err, json) {
+          if (err) {
+            return done(err);
+          }
+          assert.equal(Object.keys(json.models.User).length, 2);
+          var user = JSON.parse(json.models.User[ids[1]]);
+          assert.equal(user.name, 'John');
+          assert(user.id === ids[1]);
+          done();
+        });
       });
     });
 
+    it('should persist update', function(done) {
+      User.update({id: ids[1]}, {name: 'John1'},
+        function(err, result) {
+          if (err) {
+            return done(err);
+          }
+          readModels(function(err, json) {
+            if (err) {
+              return done(err);
+            }
+            assert.equal(Object.keys(json.models.User).length, 2);
+            var user = JSON.parse(json.models.User[ids[1]]);
+            assert.equal(user.name, 'John1');
+            assert(user.id === ids[1]);
+            done();
+          });
+        });
     });
 
     // The saved memory.json from previous test should be loaded
     it('should load from the json file', function(done) {
-    var ds = new DataSource({
-      connector: 'memory',
-      file: file
-    });
-
-    var User = ds.createModel('User', {
-      name: String,
-      bio: String,
-      approved: Boolean,
-      joinedAt: Date,
-      age: Number
-    });
-
       User.find(function(err, users) {
         // There should be 2 records
         assert.equal(users.length, 2);
@@ -93,6 +132,7 @@ describe('Memory connector', function () {
       });
 
     });
+  });
 
   describe('Query for memory connector', function() {
     var ds = new DataSource({