actionpack/test/controller/live_stream_test.rb

require 'abstract_unit'
require 'concurrent/atomic/count_down_latch'
Thread.abort_on_exception = true

module ActionController
  class SSETest < ActionController::TestCase
    class SSETestController < ActionController::Base
      include ActionController::Live

      def basic_sse
        response.headers['Content-Type'] = 'text/event-stream'
        sse = SSE.new(response.stream)
        sse.write("{\"name\":\"John\"}")
        sse.write({ name: "Ryan" })
      ensure
        sse.close
      end

      def sse_with_event
        sse = SSE.new(response.stream, event: "send-name")
        sse.write("{\"name\":\"John\"}")
        sse.write({ name: "Ryan" })
      ensure
        sse.close
      end

      def sse_with_retry
        sse = SSE.new(response.stream, retry: 1000)
        sse.write("{\"name\":\"John\"}")
        sse.write({ name: "Ryan" }, retry: 1500)
      ensure
        sse.close
      end

      def sse_with_id
        sse = SSE.new(response.stream)
        sse.write("{\"name\":\"John\"}", id: 1)
        sse.write({ name: "Ryan" }, id: 2)
      ensure
        sse.close
      end

      def sse_with_multiple_line_message
        sse = SSE.new(response.stream)
        sse.write("first line.\nsecond line.")
      ensure
        sse.close
      end
    end

    tests SSETestController

    def wait_for_response_stream_close
      response.body
    end

    def test_basic_sse
      get :basic_sse

      wait_for_response_stream_close
      assert_match(/data: {\"name\":\"John\"}/, response.body)
      assert_match(/data: {\"name\":\"Ryan\"}/, response.body)
    end

    def test_sse_with_event_name
      get :sse_with_event

      wait_for_response_stream_close
      assert_match(/data: {\"name\":\"John\"}/, response.body)
      assert_match(/data: {\"name\":\"Ryan\"}/, response.body)
      assert_match(/event: send-name/, response.body)
    end

    def test_sse_with_retry
      get :sse_with_retry

      wait_for_response_stream_close
      first_response, second_response = response.body.split("\n\n")
      assert_match(/data: {\"name\":\"John\"}/, first_response)
      assert_match(/retry: 1000/, first_response)

      assert_match(/data: {\"name\":\"Ryan\"}/, second_response)
      assert_match(/retry: 1500/, second_response)
    end

    def test_sse_with_id
      get :sse_with_id

      wait_for_response_stream_close
      first_response, second_response = response.body.split("\n\n")
      assert_match(/data: {\"name\":\"John\"}/, first_response)
      assert_match(/id: 1/, first_response)

      assert_match(/data: {\"name\":\"Ryan\"}/, second_response)
      assert_match(/id: 2/, second_response)
    end

    def test_sse_with_multiple_line_message
      get :sse_with_multiple_line_message

      wait_for_response_stream_close
      first_response, second_response = response.body.split("\n")
      assert_match(/data: first line/, first_response)
      assert_match(/data: second line/, second_response)
    end
  end

  class LiveStreamTest < ActionController::TestCase
    class Exception < StandardError
    end

    class TestController < ActionController::Base
      include ActionController::Live

      attr_accessor :latch, :tc, :error_latch

      def self.controller_path
        'test'
      end

      def set_cookie
        cookies[:hello] = "world"
        response.stream.write "hello world"
        response.close
      end

      def render_text
        render plain: 'zomg'
      end

      def default_header
        response.stream.write "<html><body>hi</body></html>"
        response.stream.close
      end

      def basic_stream
        response.headers['Content-Type'] = 'text/event-stream'
        %w{ hello world }.each do |word|
          response.stream.write word
        end
        response.stream.close
      end

      def blocking_stream
        response.headers['Content-Type'] = 'text/event-stream'
        %w{ hello world }.each do |word|
          response.stream.write word
          latch.wait
        end
        response.stream.close
      end

      def thread_locals
        tc.assert_equal 'aaron', Thread.current[:setting]
        tc.assert_not_equal Thread.current.object_id, Thread.current[:originating_thread]

        response.headers['Content-Type'] = 'text/event-stream'
        %w{ hello world }.each do |word|
          response.stream.write word
        end
        response.stream.close
      end

      def with_stale
        render plain: 'stale' if stale?(etag: "123", template: false)
      end

      def exception_in_view
        render 'doesntexist'
      end

      def exception_in_view_after_commit
        response.stream.write ""
        render 'doesntexist'
      end

      def exception_with_callback
        response.headers['Content-Type'] = 'text/event-stream'

        response.stream.on_error do
          response.stream.write %(data: "500 Internal Server Error"\n\n)
          response.stream.close
        end

        response.stream.write "" # make sure the response is committed
        raise 'An exception occurred...'
      end

      def exception_in_controller
        raise Exception, 'Exception in controller'
      end

      def bad_request_error
        raise ActionController::BadRequest
      end

      def exception_in_exception_callback
        response.headers['Content-Type'] = 'text/event-stream'
        response.stream.on_error do
          raise 'We need to go deeper.'
        end
        response.stream.write ''
        response.stream.write params[:widget][:didnt_check_for_nil]
      end

      def overfill_buffer_and_die
        logger = ActionController::Base.logger || Logger.new($stdout)
        response.stream.on_error do
          logger.warn 'Error while streaming'
          error_latch.count_down
        end

        # Write until the buffer is full. It doesn't expose that
        # information directly, so we must hard-code its size:
        10.times do
          response.stream.write '.'
        end
        # .. plus one more, because the #each frees up a slot:
        response.stream.write '.'

        latch.count_down

        # This write will block, and eventually raise
        response.stream.write 'x'

        20.times do
          response.stream.write '.'
        end
      end

      def ignore_client_disconnect
        response.stream.ignore_disconnect = true

        response.stream.write '' # commit

        # These writes will be ignored
        15.times do
          response.stream.write 'x'
        end

        logger.info 'Work complete'
        latch.count_down
      end
    end

    tests TestController

    def assert_stream_closed
      assert response.stream.closed?, 'stream should be closed'
      assert response.sent?, 'stream should be sent'
    end

    def capture_log_output
      output = StringIO.new
      old_logger, ActionController::Base.logger = ActionController::Base.logger, ActiveSupport::Logger.new(output)

      begin
        yield output
      ensure
        ActionController::Base.logger = old_logger
      end
    end

    def test_set_cookie
      get :set_cookie
      assert_equal({'hello' => 'world'}, @response.cookies)
      assert_equal "hello world", @response.body
    end

    def test_write_to_stream
      get :basic_stream
      assert_equal "helloworld", @response.body
      assert_equal 'text/event-stream', @response.headers['Content-Type']
    end

    def test_async_stream
      rubinius_skip "https://github.com/rubinius/rubinius/issues/2934"

      @controller.latch = Concurrent::CountDownLatch.new
      parts             = ['hello', 'world']

      get :blocking_stream

      t = Thread.new(response) { |resp|
        resp.await_commit
        resp.stream.each do |part|
          assert_equal parts.shift, part
          ol = @controller.latch
          @controller.latch = Concurrent::CountDownLatch.new
          ol.count_down
        end
      }

      assert t.join(3), 'timeout expired before the thread terminated'
    end

    def test_abort_with_full_buffer
      @controller.latch = Concurrent::CountDownLatch.new
      @controller.error_latch = Concurrent::CountDownLatch.new

      capture_log_output do |output|
        get :overfill_buffer_and_die, :format => 'plain'

        t = Thread.new(response) { |resp|
          resp.await_commit
          _, _, body = resp.to_a
          body.each do
            @controller.latch.wait
            body.close
            break
          end
        }

        t.join
        @controller.error_latch.wait
        assert_match 'Error while streaming', output.rewind && output.read
      end
    end

    def test_ignore_client_disconnect
      @controller.latch = Concurrent::CountDownLatch.new

      capture_log_output do |output|
        get :ignore_client_disconnect

        t = Thread.new(response) { |resp|
          resp.await_commit
          _, _, body = resp.to_a
          body.each do
            body.close
            break
          end
        }

        t.join
        Timeout.timeout(3) do
          @controller.latch.wait
        end
        assert_match 'Work complete', output.rewind && output.read
      end
    end

    def test_thread_locals_get_copied
      @controller.tc = self
      Thread.current[:originating_thread] = Thread.current.object_id
      Thread.current[:setting]            = 'aaron'

      get :thread_locals
    end

    def test_live_stream_default_header
      get :default_header
      assert response.headers['Content-Type']
    end

    def test_render_text
      get :render_text
      assert_equal 'zomg', response.body
      assert_stream_closed
    end

    def test_exception_handling_html
      assert_raises(ActionView::MissingTemplate) do
        get :exception_in_view
      end

      capture_log_output do |output|
        get :exception_in_view_after_commit
        assert_match %r((window\.location = "/500\.html"</script></html>)$), response.body
        assert_match 'Missing template test/doesntexist', output.rewind && output.read
        assert_stream_closed
      end
      assert response.body
      assert_stream_closed
    end

    def test_exception_handling_plain_text
      assert_raises(ActionView::MissingTemplate) do
        get :exception_in_view, format: :json
      end

      capture_log_output do |output|
        get :exception_in_view_after_commit, format: :json
        assert_equal '', response.body
        assert_match 'Missing template test/doesntexist', output.rewind && output.read
        assert_stream_closed
      end
    end

    def test_exception_callback_when_committed
      current_threads = Thread.list

      capture_log_output do |output|
        get :exception_with_callback, format: 'text/event-stream'

        # Wait on the execution of all threads
        (Thread.list - current_threads).each(&:join)

        assert_equal %(data: "500 Internal Server Error"\n\n), response.body
        assert_match 'An exception occurred...', output.rewind && output.read
        assert_stream_closed
      end
    end

    def test_exception_in_controller_before_streaming
      assert_raises(ActionController::LiveStreamTest::Exception) do
        get :exception_in_controller, format: 'text/event-stream'
      end
    end

    def test_bad_request_in_controller_before_streaming
      assert_raises(ActionController::BadRequest) do
        get :bad_request_error, format: 'text/event-stream'
      end
    end

    def test_exceptions_raised_handling_exceptions_and_committed
      capture_log_output do |output|
        get :exception_in_exception_callback, format: 'text/event-stream'
        assert_equal '', response.body
        assert_match 'We need to go deeper', output.rewind && output.read
        assert_stream_closed
      end
    end

    def test_stale_without_etag
      get :with_stale
      assert_equal 200, response.status.to_i
    end

    def test_stale_with_etag
      @request.if_none_match = %(W/"#{Digest::MD5.hexdigest('123')}")
      get :with_stale
      assert_equal 304, response.status.to_i
    end
  end

  class BufferTest < ActionController::TestCase
    def test_nil_callback
      buf = ActionController::Live::Buffer.new nil
      assert buf.call_on_error
    end
  end
end

class LiveStreamRouterTest < ActionDispatch::IntegrationTest
  class TestController < ActionController::Base
    include ActionController::Live

    def index
      response.headers['Content-Type'] = 'text/event-stream'
      sse = SSE.new(response.stream)
      sse.write("{\"name\":\"John\"}")
      sse.write({ name: "Ryan" })
    ensure
      sse.close
    end
  end

  def self.call(env)
    routes.call(env)
  end

  def self.routes
    @routes ||= ActionDispatch::Routing::RouteSet.new
  end

  routes.draw do
    get '/test' => 'live_stream_router_test/test#index'
  end

  def app
    self.class
  end

  test "streaming served through the router" do
    get "/test"

    assert_response :ok
    assert_match(/data: {\"name\":\"John\"}/, response.body)
    assert_match(/data: {\"name\":\"Ryan\"}/, response.body)
  end
end