Rails seed - Pass variable from one seed file to another-CodePudding

I have an app with multiple models seeding. To better handling seeds I would like to split one big file to multiple sub-seed files. In the original process I used variables to reference objects, like:

fruit = Category.create(id: '123', name: 'Fruit', ...)

and then

apple = Product.create(id: '012', name: 'apple', category: fruit), where fruit is the category created before this line.

If i split the creation of categories and products in 2 files, how do i pass fruit as variable to the other seed? I tought it would be accessible, but unfortunately i get

NameError: undefined local variable or method `fruit' for main:Object

CodePudding user response：

Variables cannot be passed across files like this in Ruby. My recommended way to accomplish your goal is to utilize the ActiveRecord relationship between Category and Product.

# ../seeds/categories.rb

## notice that i removed the assignment of the id column, ActiveRecord will do that automatically for you!

Category.create(name: 'Fruit', ...)
Category.create(name: 'Vegetable', ...)
Category.create(name: 'Carb', ...)

# ../seeds/products.rb

## query for and store the categories
fruit_category = Category.find_by(name: 'Fruit')
veg_category = Category.find_by(name: 'Vegetable')
carb_category = Category.find_by(name: 'Carb')

## assign these to variables if they need to be used later in this file
Product.create(name: 'apple', category: fruit_category)
Product.create(name: 'banana', category: fruit_category)

Product.create(name: 'broccoli', category: veg_category)
Product.create(name: 'spinach', category: veg_category)

Product.create(name: 'rice', category: carb_category)
Product.create(name: 'bread', category: carb_category)

CodePudding user response：

You would be use the FactoryBot to generate the seeds. This is the way to simplificate this process.

First, add gem factory_bot_rails:

# Gemfile
...
group :development, :test do
  ...
  gem 'factory_bot_rails', '~> 6.1'
  ...

define factories:

# spec/factories/categories.rb
# frozen_string_literal: true

FactoryBot.define do
  factory :category do
    sequence(:name) { |n| "#{n}_th_category" }
    ...

# spec/factories/products.rb
FactoryBot.define do
  factory :product do
    sequence(:name) { |n| "#{n}_th_product" }
    category
    ...

And then, you can use factories in seeds and specs:

# db/seeds/development.rb

include FactoryBot::Syntax::Methods

fruits_category = create(:category, name: 'Fruit')
product = create(:product, name: 'apple', category: fruits_category)