test: cover NotesController, received_log and StreamingExportController

test/test_controller_streaming.rb

@@ -0,0 +1,83 @@
+require 'minitest/autorun'
+require 'prism'
+require 'support'
+
+class StreamingExportController < Prism::Controller
+  after_action :log_after
+
+  def self.after_log
+    @after_log ||= []
+  end
+
+  def export
+    headers('Content-Type' => 'text/csv')
+    stream do |out|
+      out.write("id,title\n")
+      %w[one two three].each_with_index do |title, index|
+        out.write("#{index + 1},#{title}\n")
+      end
+    end
+  end
+
+  def plain
+    json(ok: true)
+  end
+
+  private
+
+  def log_after
+    self.class.after_log << action_name
+  end
+end
+
+class StreamingApp < Prism::Application
+  get '/export', to: 'streaming_export#export'
+  get '/plain', to: 'streaming_export#plain'
+end
+
+class ControllerStreamingTest < Minitest::Test
+  include TestSupport
+
+  def setup
+    StreamingExportController.after_log.clear
+  end
+
+  def call(env)
+    StreamingApp.call(env)
+  end
+
+  def test_streaming_action_returns_a_streaming_body
+    _status, _headers, body = call(env_for(:get, '/export'))
+    assert_instance_of Prism::StreamingBody, body
+  end
+
+  def test_streaming_action_produces_chunks_in_order_when_drained
+    _status, _headers, body = call(env_for(:get, '/export'))
+    collected = []
+    body.each { |chunk| collected << chunk }
+    assert_equal ["id,title\n", "1,one\n", "2,two\n", "3,three\n"], collected
+  end
+
+  def test_streaming_action_keeps_status_and_explicit_headers
+    status, headers, _body = call(env_for(:get, '/export'))
+    assert_equal 200, status
+    assert_equal 'text/csv', headers['Content-Type']
+  end
+
+  # Regression guard: finalize_body used to call `@response.body.empty?`
+  # unconditionally after every action, which raises NoMethodError against
+  # a StreamingBody (it deliberately has no #empty?, since a producer
+  # block's total chunk count is not known up front).
+  def test_after_actions_still_run_for_a_streaming_action
+    call(env_for(:get, '/export'))
+    assert_equal ['export'], StreamingExportController.after_log
+  end
+
+  # Non-streaming actions on the same controller are unaffected by the
+  # streaming? guard added to finalize_body.
+  def test_ordinary_action_on_the_same_controller_is_unaffected
+    status, _headers, body = call(env_for(:get, '/plain'))
+    assert_equal 200, status
+    assert_equal ['{"ok":true}'], body
+  end
+end