使用 FactoryGirl 测试简单的 STI

## 使用 FactoryGirl 测试简单的 STI

ruby
# app/models/animal.rb
class Animal < ApplicationRecord
  # Common attributes
  validates :name, presence: true
end
# app/models/cat.rb
class Cat < Animal
  # Cat-specific attributes
  validates :color, presence: true
end
# app/models/dog.rb
class Dog < Animal
  # Dog-specific attributes
  validates :breed, presence: true
end

ruby
# Gemfile
gem 'factory_bot_rails'

ruby
# spec/factories/animals.rb
FactoryBot.define do
  factory :animal do
    name { Faker::Creature::Animal.name }
  end
  factory :cat, parent: :animal, class: 'Cat' do
    color { Faker::Color.color_name }
  end
  factory :dog, parent: :animal, class: 'Dog' do
    breed { Faker::Creature::Dog.breed }
  end
end

ruby
# spec/models/animal_spec.rb
require 'rails_helper'
RSpec.describe Animal, type: :model do
  it 'is valid with a name' do
    animal = build(:animal, name: 'Fluffy')
    expect(animal).to be_valid
  end
  it 'is invalid without a name' do
    animal = build(:animal, name: nil)
    expect(animal).not_to be_valid
  end
end
RSpec.describe Cat, type: :model do
  it 'is valid with a name and color' do
    cat = build(:cat, name: 'Whiskers', color: 'Gray')
    expect(cat).to be_valid
  end
  it 'is invalid without a color' do
    cat = build(:cat, name: 'Fluffy', color: nil)
    expect(cat).not_to be_valid
  end
end
RSpec.describe Dog, type: :model do
  it 'is valid with a name and breed' do
    dog = build(:dog, name: 'Fido', breed: 'Golden Retriever')
    expect(dog).to be_valid
  end
  it 'is invalid without a breed' do
    dog = build(:dog, name: 'Buddy', breed: nil)
    expect(dog).not_to be_valid
  end
end