stub_any_instance sample

stub_any_instance.rb

require "abstract_unit"
require "active_support/testing/method_call_assertions"
require "rails/command"
require "rails/commands/server/server_command"

class Rails::Engine::CommandsTasksTest < ActiveSupport::TestCase
  include ActiveSupport::Testing::MethodCallAssertions

  def setup
    @destination_root = Dir.mktmpdir("bukkits")
    Dir.chdir(@destination_root) { `bundle exec rails plugin new bukkits --mountable` }

    self.class.const_set("ENGINE_PATH", "rails/all")
  end

  def teardown
    FileUtils.rm_rf(@destination_root)
  end

  def test_help_command_work_inside_engine
    output = capture(:stderr) do
      Dir.chdir(plugin_path) { `bin/rails --help` }
    end
    assert_no_match "NameError", output
  end

  def test_server_command_work_inside_engine
    stub_any_instance(Rails::Server) do |instance|
      assert_called_with(instance, :start) do
        Rails::Command.invoke(:server)
      end
    end
  ensure
  end

  private
    def plugin_path
      "#{@destination_root}/bukkits"
    end
end