Fix Style/WordArray with encoding: binary magic comment and non-ASCII string

[pocke]

Problem

Style/WordArray cop works well with encoding: binary magic comment and a string that is invalid as UTF-8. But the cop fails with a string that is "valid" as UTF-8.

Reproduce

test.rb

# -*- encoding: binary -*-
p ["あ"]

$ rubocop --debug --only Style/WordArray test.rb --cache false
For /tmp/tmp.Xoioox1uyV: configuration from /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/config/default.yml
Inspecting 1 file
Scanning /tmp/tmp.Xoioox1uyV/test.rb
incompatible encoding regexp match (UTF-8 regexp with ASCII-8BIT string)
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/style/word_array.rb:76:in `=~'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/style/word_array.rb:76:in `!~'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/style/word_array.rb:76:in `block in complex_content?'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/style/word_array.rb:73:in `any?'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/style/word_array.rb:73:in `complex_content?'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/style/word_array.rb:45:in `on_array'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/commissioner.rb:59:in `block (2 levels) in trigger_responding_cops'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/commissioner.rb:130:in `with_cop_error_handling'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/commissioner.rb:58:in `block in trigger_responding_cops'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/commissioner.rb:57:in `each'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/commissioner.rb:57:in `trigger_responding_cops'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/commissioner.rb:34:in `block (2 levels) in <class:Commissioner>'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/ast/traversal.rb:107:in `block in on_send'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/ast/traversal.rb:104:in `each'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/ast/traversal.rb:104:in `each_with_index'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/ast/traversal.rb:104:in `on_send'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/commissioner.rb:35:in `block (2 levels) in <class:Commissioner>'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/ast/traversal.rb:13:in `walk'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/commissioner.rb:46:in `investigate'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/team.rb:116:in `investigate'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/team.rb:104:in `offenses'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cop/team.rb:44:in `inspect_file'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:277:in `inspect_file'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:225:in `block in do_inspection_loop'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:257:in `block in iterate_until_no_changes'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:250:in `loop'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:250:in `iterate_until_no_changes'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:221:in `do_inspection_loop'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:124:in `block in file_offenses'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:142:in `file_offense_cache'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:122:in `file_offenses'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:110:in `process_file'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:87:in `block in each_inspected_file'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:86:in `each'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:86:in `reduce'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:86:in `each_inspected_file'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:73:in `inspect_files'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/runner.rb:39:in `run'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cli.rb:210:in `execute_runner'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cli.rb:80:in `execute_runners'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/lib/rubocop/cli.rb:51:in `run'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/exe/rubocop:13:in `block in <top (required)>'
/home/pocke/.rbenv/versions/trunk/lib/ruby/2.7.0/benchmark.rb:308:in `realtime'
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/rubocop-0.71.0/exe/rubocop:12:in `<top (required)>'
/home/pocke/.rbenv/versions/trunk/bin/rubocop:23:in `load'
/home/pocke/.rbenv/versions/trunk/bin/rubocop:23:in `<main>'
.

1 file inspected, no offenses detected
Finished in 0.04946950823068619 seconds

Solution

Change the encoding to UTF-8 before comparing with regexp.

---

Before submitting the PR make sure the following are checked:

• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists).
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Added an entry to the Changelog if the new code introduces user-observable changes. See changelog entry format.
• The PR relates to only one subject with a clear title
  and description in grammatically correct, complete sentences.
• Run bundle exec rake default. It executes all tests and RuboCop for itself, and generates the documentation.

[bbatsov]

Thanks!