Parse Server Atomic Increment Result

In my Parse backend I have an array that contains unique number codes, so users must not be able to get the same code twice. For that reason somewhere in a column of some table I a

Solution 1:

Increment does return the final value that was atomically incremented:

1. First the unit test to show how it is used:

   fit('increment', (done) => {
       new Parse.Object('Counter')
         .set('value', 1)
         .save()
         .then(result => {
           console.log('just saved', JSON.stringify(result));
           return result
             .increment('value')
             .save();
         })
         .then(result => {
           console.log('incremented', JSON.stringify(result))
           expect(result.get('value')).toBe(2);
           done();
         })
         .catch(done.fail);
     });
   

2. Behind the scenes, here's what's happening (if you're using mongo, there's similar for postgress too):

   • MongoAdapter turns into a mongo $inc operation which is returned
   • Mongo documentation explaining $inc which includes "$inc is an atomic operation within a single document."