我应该在哪里创建共享的FactoryBot关联？

Question

I have a User model that has_one required Company . Using FactoryBot, I want to create several users that share that same company. I saw some advice which I interpreted as suggesting I create Company objects within my FactoryBot.define do block, which I can use as attributes for my users:

# In spec/factories/companies.rb
FactoryBot.define do
  factory :company do
    name { 'MyCompany' }
  end
end


# In spec/factories/users.rb
FactoryBot.define do
  company1 = FactoryBot.create(:company)  # this will be shared by several users

  factory :user1 do
    first_name { 'Joe' } 
    last_name { 'Smith' } 
    company_id { company1.id }
  end

  factory :user2 do
    first_name { 'Sam' } 
    last_name { 'Smith' } 
    company_id { company1.id }
  end
end

This appears to work at first, except when I need to re-create the database from scratch in a test container with rake db:create . When rake runs, it seems to initialize my factories and the FactoryBot.create(:company) step tries to run, and there is no db schema in place, so it fails:

$ RAILS_ENV=test  bundle exec rake db:rebuild
rake aborted!
ActiveRecord::StatementInvalid: PG::UndefinedTable: ERROR:  relation "companies" does not exist
LINE 8:                WHERE a.attrelid = '"companies"'::regclass
                                          ^
:               SELECT a.attname, format_type(a.atttypid, a.atttypmod),
                     pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod,
                     c.collname, col_description(a.attrelid, a.attnum) AS comment
                FROM pg_attribute a
                LEFT JOIN pg_attrdef d ON a.attrelid = d.adrelid AND a.attnum = d.adnum
                LEFT JOIN pg_type t ON a.atttypid = t.oid
                LEFT JOIN pg_collation c ON a.attcollation = c.oid AND a.attcollation <> t.typcollation
               WHERE a.attrelid = '"companies"'::regclass
                 AND a.attnum > 0 AND NOT a.attisdropped
               ORDER BY a.attnum

This makes me think that I'm trying to create these in the wrong place.

Where is the best place to set up shared associations like company1 for my test data so that it occurs after my app properly initializes and before my test suite is executed?

FWIW, here's the error stack:

ActiveRecord::StatementInvalid: PG::UndefinedTable: ERROR:  relation "companies" does not exist
LINE 8:                WHERE a.attrelid = '"companies"'::regclass
                                          ^
:               SELECT a.attname, format_type(a.atttypid, a.atttypmod),
                     pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod,
                     c.collname, col_description(a.attrelid, a.attnum) AS comment
                FROM pg_attribute a
                LEFT JOIN pg_attrdef d ON a.attrelid = d.adrelid AND a.attnum = d.adnum
                LEFT JOIN pg_type t ON a.atttypid = t.oid
                LEFT JOIN pg_collation c ON a.attcollation = c.oid AND a.attcollation <> t.typcollation
               WHERE a.attrelid = '"companies"'::regclass
                 AND a.attnum > 0 AND NOT a.attisdropped
               ORDER BY a.attnum
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Answer 1

When you create objects in this way - they are created each time factories are initialised, no matter if they will be used in particular test run or not.

It's usually better to have independent factories and explicitly state in your tests that you want two users from same company:

 let(:company){ create :company }
 let(:user1){ create :user, company: company }
 let(:user2){ create :user, company: company }

For cases when you do not care about exact relation and just want to reuse some valid value and avoid relations cascading - there's create_default workaround in test-prof gem (see more here )