require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'

  gem 'mongoid'
end

require 'tempfile'

Tempfile.open(%w(config .yml)) do |f|
  uri = 'mongodb://mongo/test'

  f.write(<<~YAML)
development:
  clients:
    default:
      uri: #{uri}
  YAML
  f.flush

  Mongoid.load!(f.path, 'development')
  Mongoid::Clients.clients.each do |_, client|
    client.logger.level = Logger::ERROR
  end
end

class Parent
  include Mongoid::Document

  has_one :child
end

class Child
  include Mongoid::Document
end

Parent.new.child = Child.new

__END__
Traceback (most recent call last):
        7: from hi.rb:38:in `<main>'
        6: from /usr/local/bundle/gems/mongoid-7.1.2/lib/mongoid/association/accessors.rb:290:in `block (2 levels) in define_setter!'
        5: from /usr/local/bundle/gems/mongoid-7.1.2/lib/mongoid/association/accessors.rb:183:in `without_autobuild'
        4: from /usr/local/bundle/gems/mongoid-7.1.2/lib/mongoid/association/accessors.rb:299:in `block (3 levels) in define_setter!'
        3: from /usr/local/bundle/gems/mongoid-7.1.2/lib/mongoid/association/accessors.rb:30:in `__build__'
        2: from /usr/local/bundle/gems/mongoid-7.1.2/lib/mongoid/association/accessors.rb:50:in `create_relation'
        1: from /usr/local/bundle/gems/mongoid-7.1.2/lib/mongoid/association/referenced/has_one/buildable.rb:30:in `build'
/usr/local/bundle/gems/mongoid-7.1.2/lib/mongoid/association/referenced/has_one/buildable.rb:38:in `clear_associated': nil is not a symbol nor a string (TypeError)