DB state shouldn't be modified when the returned objects are modified

lib/datastore.js

@@ -129,7 +129,7 @@ Datastore.prototype.find = function (query, callback) {
 
   for (i = 0; i < self.data.length; i += 1) {
     if (Datastore.match(self.data[i], query)) {
-      res.push(self.data[i]);
+      res.push(model.deepCopy(self.data[i]));
     }
   }
 
@@ -148,7 +148,7 @@ Datastore.prototype.findOne = function (query, callback) {
 
   for (i = 0; i < self.data.length; i += 1) {
     if (Datastore.match(self.data[i], query)) {
-      return callback(null, self.data[i]);
+      return callback(null, model.deepCopy(self.data[i]));
     }
   }
 

test/db.test.js

@@ -108,6 +108,30 @@ describe('Database', function () {
       });
     });
 
+    it('If an object returned from the DB is modified and refetched, the original value should be found', function (done) {
+      d.insert({ a: 'something' }, function () {
+        d.findOne({}, function (err, doc) {
+          doc.a.should.equal('something');
+          doc.a = 'another thing';
+          doc.a.should.equal('another thing');
+
+          // Re-fetching with findOne should yield the persisted value
+          d.findOne({}, function (err, doc) {
+            doc.a.should.equal('something');
+            doc.a = 'another thing';
+            doc.a.should.equal('another thing');
+
+            // Re-fetching with find should yield the persisted value
+            d.find({}, function (err, docs) {
+              docs[0].a.should.equal('something');
+
+              done();
+            });
+          });
+        });
+      });
+    });
+
   });   // ==== End of 'Insert' ==== //