RSpec with FactoryGirl/Bot - undefined method 'user' on model that belongs to user through has_many :through - ruby

Question

Trying to get into proper testing and figure out the ins and outs of basic RSpec with FactoryBot.
NOTE: The validation tests all passed previously and they're in the model files. I've just removed them for the sake of reducing clutter.
My models:
models/user.rb
has_many :fulfillments
has_many :milestones, through: :fulfillments
models/fulfillment.rb
has_many :milestones
belongs_to :user
models/milestone.rb
belongs_to :fulfillments
My Factories:
spec/factories/users.rb
require 'faker'
FactoryBot.define do
factory :user do
first_name Faker::Name.first_name
last_name Faker::Name.last_name
preferred_name Faker::Name.first_name
username Faker::Internet.user_name
email Faker::Internet.email
password 'password123'
password_confirmation 'password123'
factory :user_with_fulfillments do
transient do
fulfillments_count 3
end
after(:create) do |user, e|
create_list(:fulfillment_with_milestones, e.fulfillments_count, user: user)
end
end
end
end
spec/factories/fulfillments.rb
require 'faker'
FactoryBot.define do
factory :fulfillment do
title Faker::Lorem.words.join(' ')
description Faker::Lorem.sentences.join(' ')
promise Faker::Lorem.sentence
reason Faker::Lorem.sentence
association :user, factory: :user_with_fulfillments
trait :userless do
user nil
end
factory :fulfillment_with_milestones do
transient do
milestones_count 2
end
after(:create) do |fulfillment, e|
create_list(:milestone, e.milestones_count, fulfillment: fulfillment)
end
end
end
end
spec/factories/milestones.rb
require 'faker'
FactoryBot.define do
factory :milestone do
title Faker::Lorem.words.join(' ')
criteria Faker::Lorem.sentences.join("\n")
reason Faker::Lorem.sentence
deadline Faker::Date.forward(30)
association :fulfillment, factory: :fulfillment_with_milestones
end
end
One test that's giving me trouble (spec/models/milestone.rb)
require 'rails_helper'
RSpec.describe Milestone, type: :model do
it 'has a valid factory' do
expect(create(:milestone)).to be_valid
end
it 'validates attributes correctly' do
should validate_presence_of :fulfillment
should validate_presence_of :title
should validate_presence_of :criteria
end
end
Error I'm getting in ANY test that involves the milestones factory
Failures:
1) Fulfillment has a valid factory
Failure/Error: create_list(:milestone, e.milestones_count, fulfillment: fulfillment)
NoMethodError:
undefined method `user' for #<Milestone:0x00007f844d54f1b8>
# ./spec/factories/fulfillments.rb:22:in `block (4 levels) in <top (required)>'
# ./spec/factories/users.rb:19:in `block (4 levels) in <top (required)>'
# ./spec/models/fulfillment_spec.rb:6:in `block (2 levels) in <top (required)>'
2) Milestone has a valid factory
Failure/Error: expect(create(:milestone)).to be_valid
NoMethodError:
undefined method `user' for #<Milestone:0x00007f844d8d0b98>
# ./spec/models/milestone_spec.rb:6:in `block (2 levels) in <top (required)>'
3) Milestone validates attributes correctly
Failure/Error: should validate_presence_of :fulfillment
NoMethodError:
undefined method `user' for #<Milestone:0x00007f8450829700>
# ./spec/models/milestone_spec.rb:10:in `block (2 levels) in <top (required)>'
4) User can have fulfillments and milestones
Failure/Error: create_list(:milestone, e.milestones_count, fulfillment: fulfillment)
NoMethodError:
undefined method `user' for #<Milestone:0x00007f8450b7b9d0>
# ./spec/factories/fulfillments.rb:22:in `block (4 levels) in <top (required)>'
# ./spec/factories/users.rb:19:in `block (4 levels) in <top (required)>'
# ./spec/models/user_spec.rb:29:in `block (2 levels) in <top (required)>'
Finished in 0.26253 seconds (files took 5.19 seconds to load)
9 examples, 4 failures, 1 pending
Failed examples:
rspec ./spec/models/fulfillment_spec.rb:5 # Fulfillment has a valid factory
rspec ./spec/models/milestone_spec.rb:5 # Milestone has a valid factory
rspec ./spec/models/milestone_spec.rb:9 # Milestone validates attributes correctly
rspec ./spec/models/user_spec.rb:28 # User can have fulfillments and milestones
Mostly confused because I'm not sure where or why it's trying to call #user on an instance of Milestone. The factories create Fulfillments for a User, then Milestones for the Fulfillments.
PS: It's my first time posting to StackOverflow (I usually manage to find answers to my really simple questions) so feel free to let me know if there's anything I could do to make future questions clearer.

Answer 1

It turns out I'm an idiot. I had a
validates :user, :presence
on my Milestone model. No wonder why it was trying to call milestone.user
Forget this ever happened please. ]:

Answer 2

Try to define classes explicitly in your factories so that they are not guessed but known.
factory :user, class: User
and
factory :fulfillment, class: FulFillment