Protect against missing parents

[gjtorikian]

There's a slight logical error in the recent DuplicateTestRun addition.

Totally legit Ruby code can be marked as unparseable by this test:

         parent_class_node = class_node_parent.each_child_node(:class).detect do |klass|
                              ^^^^^^^^^^^^^^^^^
Did you mean?  class_node
    /Users/gjtorikian/Development/rubocop-minitest/lib/rubocop/cop/minitest/duplicate_test_run.rb:69:in `parent_class_has_test_methods?'
    /Users/gjtorikian/Development/rubocop-minitest/lib/rubocop/cop/minitest/duplicate_test_run.rb:56:in `on_class'
    /Users/gjtorikian/.gem/bundler/gems/rubocop-2d3a972cb12b/lib/rubocop/cop/commissioner.rb:100:in `public_send'
    /Users/gjtorikian/.gem/bundler/gems/rubocop-2d3a972cb12b/lib/rubocop/cop/commissioner.rb:100:in `block (2 levels) in trigger_responding_cops'
    /Users/gjtorikian/.gem/bundler/gems/rubocop-2d3a972cb12b/lib/rubocop/cop/commissioner.rb:160:in `with_cop_error_handling'
    /Users/gjtorikian/.gem/bundler/gems/rubocop-2d3a972cb12b/lib/rubocop/cop/commissioner.rb:99:in `block in trigger_responding_cops'
    /Users/gjtorikian/.gem/bundler/gems/rubocop-2d3a972cb12b/lib/rubocop/cop/commissioner.rb:98:in `each'
    /Users/gjtorikian/.gem/bundler/gems/rubocop-2d3a972cb12b/lib/rubocop/cop/commissioner.rb:98:in `trigger_responding_cops'
    /Users/gjtorikian/.gem/bundler/gems/rubocop-2d3a972cb12b/lib/rubocop/cop/commissioner.rb:69:in `on_class'
    /Users/gjtorikian/.gem/gems/rubocop-ast-1.16.0/lib/rubocop/ast/traversal.rb:136:in `block in on_dstr'
    /Users/gjtorikian/.gem/gems/rubocop-ast-1.16.0/lib/rubocop/ast/traversal.rb:136:in `each'
    /Users/gjtorikian/.gem/gems/rubocop-ast-1.16.0/lib/rubocop/ast/traversal.rb:136:in `on_dstr'
    /Users/gjtorikian/.gem/bundler/gems/rubocop-2d3a972cb12b/lib/rubocop/cop/commissioner.rb:71:in `on_begin'
    /Users/gjtorikian/.gem/gems/rubocop-ast-1.16.0/lib/rubocop/ast/traversal.rb:20:in `walk'
    /Users/gjtorikian/.gem/bundler/gems/rubocop-2d3a972cb12b/lib/rubocop/cop/commissioner.rb:86:in `investigate'
    /Users/gjtorikian/.gem/bundler/gems/rubocop-2d3a972cb12b/lib/rubocop/cop/team.rb:155:in `investigate_partial'
    /Users/gjtorikian/.gem/bundler/gems/rubocop-2d3a972cb12b/lib/rubocop/cop/team.rb:83:in `investigate'
    /Users/gjtorikian/Development/rubocop-minitest/lib/rubocop/minitest/assert_offense.rb:114:in `_investigate'
    /Users/gjtorikian/Development/rubocop-minitest/lib/rubocop/minitest/assert_offense.rb:105:in `assert_offense'
    /Users/gjtorikian/Development/rubocop-minitest/test/rubocop/cop/minitest/duplicate_test_run_test.rb:23:in `test_registers_offense_when_parent_and_children_have_tests_methods'

The solution to this is to not assume that every test file has a parent class. I added a failing test case to demonstrate this bug, and then the second commit is the change to fix it.

[koic]

Can you add a changelog entry and squash your commits into one?

• Added an entry (file) to the changelog folder named {change_type}_{change_description}.md if the new code introduces user-observable changes. See changelog entry format for details.

[gjtorikian]

@koic Done!

[koic]

This looks good. Can you squash commits into one?

[gjtorikian]

This looks good. Can you squash commits into one?

Yes, done!

[koic]

Thanks!

[gjtorikian]

Thank you! Any chance for a patch version bump?

[koic]

@gjtorikian Yeah, RuboCop Minitest 0.19.1 has been released.
https://github.com/rubocop/rubocop-minitest/releases/tag/v0.19.1