Rails 5.1.4 test throws NameError only when testing fails

Question

When running rails test that fails, in a 5.1.4 rails app it throws the following NameError.

Traceback (most recent call last):
27: from -e:1:in `<main>'
26: from /Users/User/.rvm/rubies/ruby-2.5.0/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'
25: from /Users/User/.rvm/rubies/ruby-2.5.0/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'
24: from /Users/User/.rvm/gems/ruby-2.5.0/gems/spring-2.0.2/lib/spring/application/boot.rb:19:in `<top (required)>'
23: from /Users/User/.rvm/gems/ruby-2.5.0/gems/spring-2.0.2/lib/spring/application.rb:135:in `run'
22: from /Users/User/.rvm/gems/ruby-2.5.0/gems/spring-2.0.2/lib/spring/application.rb:135:in `loop'
21: from /Users/User/.rvm/gems/ruby-2.5.0/gems/spring-2.0.2/lib/spring/application.rb:141:in `block in run'
20: from /Users/User/.rvm/gems/ruby-2.5.0/gems/spring-2.0.2/lib/spring/application.rb:171:in `serve'
19: from /Users/User/.rvm/gems/ruby-2.5.0/gems/spring-2.0.2/lib/spring/application.rb:171:in `fork'
18: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:63:in `block in autorun'
17: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:136:in `run'
16: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:159:in `__run'
15: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:159:in `map'
14: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:159:in `block in __run'
13: from /Users/User/.rvm/gems/ruby-2.5.0/gems/railties-5.1.4/lib/rails/test_unit/line_filtering.rb:9:in `run'
12: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:319:in `run'
11: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:347:in `with_info_handler'
10: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:360:in `on_signal'
 9: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:320:in `block in run'
 8: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:320:in `each'
 7: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:321:in `block (2 levels) in run'
 6: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:334:in `run_one_method'
 5: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:785:in `record'
 4: from /Users/v/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:785:in `each'
 3: from /Users/User/.rvm/gems/ruby-2.5.0/gems/minitest-5.11.1/lib/minitest.rb:786:in `block in record'
 2: from /Users/User/.rvm/gems/ruby-2.5.0/gems/railties-5.1.4/lib/rails/test_unit/reporter.rb:23:in `record'
 1: from /Users/User/.rvm/gems/ruby-2.5.0/gems/railties-5.1.4/lib/rails/test_unit/reporter.rb:70:in `format_rerun_snippet'
/Users/User/.rvm/gems/ruby-2.5.0/gems/railties-5.1.4/lib/rails/test_unit/reporter.rb:70:in `method': undefined method       `test_should_get_help' for class `Minitest::Result' (NameError)

However, if the test passes, the minitest report is shown without error messages at all. I tried removing the minitest-reporters gem, but the NameError message does not go away. Seems to be related to the spring server. I also tried shutting down all spring ps. Regarding `test_should_get_help' is a simple tests and despite deleting it, the error always puts the last written test in its place.

This is the Gemfile

    source 'https://rubygems.org'

gem 'rails',                   '5.1.4'
gem 'bcrypt',                  '3.1.11'
gem 'faker',                   '1.7.3'
gem 'carrierwave',             '1.2.2'
gem 'mini_magick',             '4.7.0'
gem 'will_paginate',           '3.1.6'
gem 'bootstrap-will_paginate', '1.0.0'
gem 'bootstrap-sass',          '3.3.7'
gem 'puma',                    '3.9.1'
gem 'sass-rails',              '5.0.6'
gem 'uglifier',                '3.2.0'
gem 'coffee-rails',            '4.2.2'
gem 'jquery-rails',            '4.3.1'
gem 'turbolinks',              '5.0.1'
gem 'jbuilder',                '2.7.0'

group :development, :test do
  gem 'sqlite3', '1.3.13'
  gem 'byebug',  '9.0.6', platform: :mri
end

group :development do
  gem 'web-console',           '3.5.1'
  gem 'listen',                '3.1.5'
  gem 'spring',                '2.0.2'
  gem 'spring-watcher-listen', '2.0.1'
end

group :test do
  gem 'rails-controller-testing', '1.0.2'
  gem 'minitest-reporters',       '1.1.14'
  gem 'guard',                    '2.14.1'
  gem 'guard-minitest',           '2.4.6'
end

group :production do
  gem 'pg',  '0.20.0'
  gem 'fog', '1.42'
end

# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

Answer 1

I found this thread: https://github.com/seattlerb/minitest/issues/730, which promises a fix to MiniTest. The fix will be available in a future Rails update, or now via Edge Rails.

I added a temporary entry to my Gemfile to revert MiniTest to the previous stable version,

# temporary fix to minitest 5.11.1 issue 
gem 'minitest', '~>5.10.3'

and then ran

bundle update minitest

It seems to work (but I'm still getting failed tests).

YMMV