record was saved to the server, but the response does not have an id and your record does not either

I’m facing this error since yesterday, Error: Assertion Failed: 'todo' was saved to the server, but the response does not have an id and your record does not either.

I know it should come from app/serializers/todo.js or my app/routes/application.jsbut after looking into severals forum, I have to ask the question to expert emberJs dev, as i’m a newbie :smiley:

Here’s my app/serializers/todo.js:

import DS from 'ember-data';

export default DS.JSONSerializer.extend({
  serialize: function(record, options) {
    var json = this._super.apply(this, arguments); // Get default serialization

    json.id = record.id;  // tack on the id

    return json;
  }
});

And my app/routes/application.js

import Route from '@ember/routing/route';

export default Route.extend({
  model(){
    return this.store.findAll('todo');
  },
    actions: {
      createtodo: function() {

        var titleInput = this.get("newTitle")
        var todo = this.store.createRecord('todo', {
          title: titleInput,
          isCompleted: false
        }); 

        this.set('newTitle', '');
        todo.save();
      }
    }
});

The way the createtodo action is triggered app/templates/application.hbs:

<button >Save</button>

So my objec is created but not save. When i’m looking into my ember Inspector, I see that each object I create have an ID but the title field is null or "".

This is a todoApp with an Rails-API as back and Ember as front.

Anyone see what’s wrong here ?