Is there any way to omit null values?

What are you doing?

I have a model defined as bellow:

const Scene = sequelize.define(
  'scene',
  {
    sceneId: { type: Sequelize.STRING, allowNull: false, primaryKey: true },
    owner: { type: Sequelize.STRING, allowNull: false },
    name: Sequelize.STRING,
    description: Sequelize.STRING,
    width: Sequelize.INTEGER,
    height: Sequelize.INTEGER
  }
)

When I query one instance use Scene.findOne and send back to express:

const scene = Scene.findOne({...})
res.json(scene)

I get a scene like this:

{
  "sceneId": "12356",
  "owner": "sam",
  "name": null,
  "description": null,
  "width": null,
  "height": null
}

As null would break our webapp, I would like to have this:

{
  "sceneId": "12356",
  "owner": "sam"
}

Is there any way to omit these null values when calling scene.toJSON()?

To Reproduce
Steps to reproduce the behavior:

1. Define models X, Y, ...
2. Run the following
3. See error

What do you expect to happen?

I wanted Foo!

What is actually happening?

But the output was bar!

Output, either JSON or SQL

Environment

Dialect:

• mysql
• postgres
• sqlite
• mssql
• any
  Dialect library version: XXX
  Database version: XXX
  Sequelize version: XXX
  Node Version: XXX
  OS: XXX
  If TypeScript related: TypeScript version: XXX
  Tested with latest release:
• No
• Yes, specify that version:

Start with the Sequelize model defined in the issue and trace the result from Scene.findOne through scene.toJSON() before it is passed to res.json. Check the existing serialization behavior and tests, if present; the work is done when a supported approach or behavior omits null-valued attributes while retaining populated fields.