odd Metrics/ClassLength behavior

[chazlarson]

In 10-03. At this point:
In the file test/controllers/users_controller_test.rb, add the line "# rubocop:disable Metrics/ClassLength" to the very beginning of the file and the line "# rubocop:disable Metrics/ClassLength" to the very end of the file.

When I add those lines to the file, RuboCop throws an offense that their unneeded. When I remove them, I get an offense that there are too many lines in the class. I added this exclusion to .rubocop.yml instead.

no # rubocop lines in the file:

winner@2fc6a0f5360e:~/shared/generic-rails-2017-03-27-1756$ bundle exec rubocop -D
Inspecting 77 files
.................................................C...........................

Offenses:

test/controllers/users_controller_test.rb:5:1: C: Metrics/ClassLength: Class has too many lines. [116/100]
class UsersControllerTest < ActionController::TestCase ...
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

77 files inspected, 1 offense detected

Add them to the file:

winner@2fc6a0f5360e:~/shared/generic-rails-2017-03-27-1756$ bundle exec rubocop -D
Inspecting 77 files
.................................................W...........................

Offenses:

test/controllers/users_controller_test.rb:153:1: W: Lint/UnneededDisable: Unnecessary disabling of Metrics/ClassLength.
# rubocop:disable Metrics/ClassLength
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

77 files inspected, 1 offense detected