request_blocker_middleware.rb

# Prevents requests from hitting the Rails app after the test has finished.
class CapybaraRequestBlockerMiddleware
  # assignment to initialized instance variables is thread safe in Ruby
  @enabled = false

  class << self
    def enabled?
      @enabled
    end

    def enable!
      @enabled = true
    end

    def disable!
      @enabled = false
    end
  end

  def initialize(app)
    @app = app
  end

  def call(env)
    if self.class.enabled?
      @app.call(env)
    else
      [200, {}, ["Request blocked by block middleware"]]
    end
  end
end

Capybara.app = CapybaraRequestBlockerMiddleware.new(Rails.application)

RSpec.configure do |config|
  config.before do
    CapybaraRequestBlockerMiddleware.enable!
  end

  config.after do
    CapybaraRequestBlockerMiddleware.disable!
    Capybara.reset_sessions!
    DatabaseCleaner.clean
  end
end