test: cover test_dispatch_emits_process_action_event_with_status

test/test_application_error_handling.rb

@@ -0,0 +1,57 @@
+require 'minitest/autorun'
+require 'prism'
+require 'support'
+
+class ErrorHandlingBoomController < Prism::Controller
+  def index
+    raise 'kaboom, no rescue_from anywhere for this one'
+  end
+end
+
+class ErrorHandlingFineController < Prism::Controller
+  def index
+    halt(200, 'fine')
+  end
+end
+
+class ErrorHandlingApp < Prism::Application
+  get '/boom', to: 'error_handling_boom#index'
+  get '/fine', to: 'error_handling_fine#index'
+end
+
+class ApplicationErrorHandlingTest < Minitest::Test
+  include TestSupport
+
+  def call(method, path, **opts)
+    ErrorHandlingApp.call(env_for(method, path, **opts))
+  end
+
+  def test_unhandled_exception_becomes_a_safe_500_instead_of_crashing_the_request
+    status, headers, body = call('GET', '/boom')
+    assert_equal 500, status
+    assert_equal 'text/plain', headers['Content-Type']
+    assert_equal 'Internal Server Error', body.join
+  end
+
+  def test_the_500_body_never_leaks_the_exception_message
+    _, _, body = call('GET', '/boom')
+    refute_includes body.join, 'kaboom'
+  end
+
+  def test_unrelated_requests_are_unaffected_by_the_fallback
+    status, _, body = call('GET', '/fine')
+    assert_equal 200, status
+    assert_equal 'fine', body.join
+  end
+
+  def test_the_exception_is_still_recorded_on_the_instrumentation_payload
+    events = []
+    subscriber = Prism::Instrumentation.subscribe('process_action.prism') { |event| events << event }
+    call('GET', '/boom')
+    klass, message = events.last.payload[:exception]
+    assert_equal 'RuntimeError', klass
+    assert_includes message, 'kaboom'
+  ensure
+    Prism::Instrumentation.unsubscribe(subscriber)
+  end
+end