Rails 5: Dump Rails db to fixtures

db_fixtures_dump.rake

# frozen_string_literal: true

# Original from http://snippets.dzone.com/posts/show/4468 by MichaelBoutros
#
# Optimized version which uses to_yaml for content creation and checks
# that models are ActiveRecord::Base models before trying to fetch
# them from database.
namespace :db do
  namespace :fixtures do
    desc "Dumps all models into fixtures."
    task :dump => :environment do
      models = Dir.glob(Rails.root + "app/models/**.rb").map do |s|
        Pathname.new(s).basename.to_s.gsub(/\.rb$/, "").camelize
      end

      # excludes models 
      excludes = %w(ApplicationRecord)

      puts "Found models: " + models.join(", ")

      models.reject { |m| m.in?(excludes) }.each do |m|
        model = m.constantize
        next unless model.ancestors.include?(ActiveRecord::Base)

        puts "Dumping model: " + m
        entries = model.order(id: :asc).all

        increment = 1
        fixtures_dir = "#{Rails.root}/#{Rails.env}/fixtures"
        FileUtils.mkdir_p(fixtures_dir)
        model_file = "#{fixtures_dir}/#{m.underscore.pluralize}.yml"
        File.open(model_file, "w") do |f|
          entries.each do |a|
            attrs = a.attributes
            attrs.delete_if { |_, v| v.blank? }

            output = { m + "_" + increment.to_s => attrs }
            f << output.to_yaml.gsub(/^--- \n/, "") + "\n"

            increment += 1
          end
        end
      end
    end
  end
end