RSpec rake support module

rake_helpers.rb

APP_RAKEFILE = Rails.root.join('Rakefile')

module Support
  module RakeHelpers
    extend ActiveSupport::Concern

    def rake(task)
      Rake::Task[task].reenable
      Rake.application.invoke_task(task)
    end

    included do
      RSpec.configure do |config|
        config.before type: :rake do
          require 'rake'

          load 'rails/tasks/engine.rake'
        end
      end
    end
  end
end

task_spec.rb

RSpec.describe 'My task', type: :rake do
  it 'works' do
    rake 'app:my:task'
  end
end