config/initializers/generators.rb

Rails.application.config.generators do |g|
  # Generate desired tests using RSpec.
  g.test_framework :rspec,
                   view_specs: false,
                   controller_specs: false,
                   feature_specs: true,
                   routing_specs: false,
                   decorator_specs: false

  # Use factory_girl for factories.
  g.fixture_replacement :factory_girl, dir: 'spec/factories'

  # Disable generators we don't need.
  g.stylesheets false
  g.javascripts false
  g.template_engine :slim
  g.helper false
end