Bugfix: Message Builder for Error Messages on testStepFinished (#1790)

* Add stack trace

* Bugfixes. Ensure casing of stack-trace property and fix stringlike nature of it

* Tidy up legacy error message method
#

* Add changelog

* Bump CCK to v19 to ensure compatibility with latest issues

* Remove superfluous step definitions in attachments

* Tidy up message element to use a heredoc

Author: luke-hill

CHANGELOG.md

@@ -9,6 +9,11 @@ This document is formatted according to the principles of [Keep A CHANGELOG](htt
 Please visit [cucumber/CONTRIBUTING.md](https://github.com/cucumber/cucumber/blob/master/CONTRIBUTING.md) for more info on how to contribute to Cucumber.
 
 ## [Unreleased]
+### Changed
+- Updated `cucumber-compatibility-kit` to v19
+
+### Fixed
+- Fixed an issue where the html-formatter wasn't respecting the new structure for `StackTrace` cucumber messages ([#1790](https://github.com/cucumber/cucumber-ruby/pull/1790) [luke-hill](https://github.com/luke-hill))
 
 ## [10.0.0] - 2025-06-11
 ### Changed

compatibility/features/attachments/attachments_steps.rb

@@ -25,16 +25,6 @@ def cck_asset_path
   attach(data, media_type)
 end
 
-# To be removed in CCK v19 alongside removing duplicate scenarios: https://github.com/cucumber/compatibility-kit/pull/127
-When('a JPEG image is attached') do
-  attach(File.open("#{cck_asset_path}/cucumber.jpeg"), 'image/jpeg')
-end
-
-# To be removed in CCK v19 alongside removing duplicate scenarios: https://github.com/cucumber/compatibility-kit/pull/127
-When('a PNG image is attached') do
-  attach(File.open("#{cck_asset_path}/cucumber.png"), 'image/png')
-end
-
 When('a PDF document is attached and renamed') do
   attach(File.open("#{cck_asset_path}/document.pdf"), 'application/pdf', 'renamed.pdf')
 end

cucumber.gemspec

@@ -35,7 +35,7 @@ Gem::Specification.new do |s|
   s.add_dependency 'multi_test', '~> 1.1'
   s.add_dependency 'sys-uname', '~> 1.3'
 
-  s.add_development_dependency 'cucumber-compatibility-kit', '~> 18.0'
+  s.add_development_dependency 'cucumber-compatibility-kit', '~> 19.0'
   # Only needed whilst we are testing the formatters. Can be removed once we remove tests for those
   s.add_development_dependency 'nokogiri', '~> 1.15'
   s.add_development_dependency 'rake', '~> 13.2'

lib/cucumber/formatter/message_builder.rb

@@ -198,9 +198,7 @@ def on_test_step_started(event)
 
       def on_test_step_finished(event)
         test_case = @test_case_by_step_id[event.test_step.id]
-        result = event
-                 .result
-                 .with_filtered_backtrace(Cucumber::Formatter::BacktraceFilter)
+        result = event.result.with_filtered_backtrace(Cucumber::Formatter::BacktraceFilter)
 
         result_message = result.to_message
         if result.failed? || result.pending?
@@ -227,14 +225,20 @@ def on_test_step_finished(event)
       end
 
       def create_error_message(message_element)
-        message = "#{message_element.message} (#{message_element.class})"
-        ([message] + message_element.backtrace).join("\n")
+        <<~ERROR_MESSAGE
+          #{message_element.message} (#{message_element.class})
+          #{message_element.backtrace}
+        ERROR_MESSAGE
       end
 
       def create_exception_object(result, message_element)
         return unless result.failed?
 
-        Cucumber::Messages::Exception.from_h({ type: message_element.class, message: message_element.message })
+        Cucumber::Messages::Exception.new(
+          type: message_element.class,
+          message: message_element.message,
+          stack_trace: message_element.backtrace.join("\n")
+        )
       end
 
       def on_test_case_finished(event)