How to create a object in ember-cli-mirage?

Question

I have a foo model that hasMany bar and bar belongsTo baz . How can I include the creation of baz when a foo is created together with it's bar ? Whenver a foo is created a 10 bar must create and a baz is created for each bar

On my /factories/foo.js I have a

  afterCreate(foo, server) {
    server.createList('bar', 10, { foo });
  }

Answer 1

One option would be to have the bar factory create its own baz :

// factories/bar.js
export default Factory.extend({
  afterCreate(bar, server) {
    bar.update({
      baz: server.create('baz')
    })
  }
})

This way, every time server.create('bar') is called (no matter where), each bar would get updated with its own baz .

You could even use the association helper to do this for you – it basically takes care of this special case of creating a belongsTo relationship whenever the base model is created:

import { Factory, association } from 'ember-cli-mirage';

// factories/bar.js
export default Factory.extend({
  baz: association()
})

You could also do it directly from the foo factory:

// factories/foo.js
afterCreate(foo, server) {
  server.createList('bar', 10, { foo }).forEach(bar => {
    bar.update({
      baz: server.create('baz')
    })
  });
}

Just note that base factories should be the minimal valid descriptions of your models + their relationships – if you put these auto-creating relationships in each base factory and then someone wants to write a test for a situation where these relationships don't exist, it'll be difficult for them. The traits feature is designed specifically to alleviate this sort of thing:

// factories/bar.js
Factory.extend({
  withBaz: trait({
    baz: association()
  })
})

// factories/foo.js
Factory.extend({
  afterCreate(foo, server) {
    server.createList('bar', 10, 'withBaz', { foo });
  }
})

Also be sure to give the factory best practices guide a read! :)