Lint/AmbiguousRegexpLiteral - Error occurs when running rubocop.

[mjnohai]

Error occurs when running rubocop for the AmbiguousRegexpLiteral linter. The error did not occur on the previous version, 0.92.0.

---

Expected behavior

Rubocop shouldn't have an error as the regular expression used here is valid.

Actual behavior

An error occurred while Lint/AmbiguousRegexpLiteral cop was inspecting ./projects/MIST/pages/imedidata/course.rb.
undefined method `receiver' for nil:NilClass
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:64:in `method_chain_to_regexp_receiver?'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:56:in `find_offense_node'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:50:in `find_offense_node_by'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:35:in `block in on_new_investigation'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:32:in `each'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:32:in `on_new_investigation'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:143:in `block (2 levels) in invoke'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:152:in `with_cop_error_handling'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:142:in `block in invoke'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:141:in `each'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:141:in `invoke'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:83:in `investigate'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/team.rb:152:in `investigate_partial'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cop/team.rb:83:in `investigate'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:315:in `inspect_file'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:259:in `block in do_inspection_loop'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:293:in `block in iterate_until_no_changes'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:286:in `loop'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:286:in `iterate_until_no_changes'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:255:in `do_inspection_loop'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:132:in `block in file_offenses'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:157:in `file_offense_cache'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:131:in `file_offenses'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:122:in `process_file'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:101:in `block in each_inspected_file'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:100:in `each'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:100:in `reduce'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:100:in `each_inspected_file'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:86:in `inspect_files'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/runner.rb:47:in `run'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cli/command/execute_runner.rb:25:in `execute_runner'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cli/command/execute_runner.rb:17:in `run'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cli/command.rb:11:in `run'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cli/environment.rb:18:in `run'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cli.rb:65:in `run_command'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cli.rb:72:in `execute_runners'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/lib/rubocop/cli.rb:41:in `run'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/exe/rubocop:13:in `block in <top (required)>'
.rvm/rubies/ruby-2.6.6/lib/ruby/2.6.0/benchmark.rb:308:in `realtime'
.rvm/gems/ruby-2.6.6@mist/gems/rubocop-0.93.0/exe/rubocop:12:in `<top (required)>'
.rvm/gems/ruby-2.6.6@mist/bin/rubocop:23:in `load'
.rvm/gems/ruby-2.6.6@mist/bin/rubocop:23:in `<main>'
.rvm/gems/ruby-2.6.6@mist/bin/ruby_executable_hooks:24:in `eval'
.rvm/gems/ruby-2.6.6@mist/bin/ruby_executable_hooks:24:in `<main>'

Steps to reproduce the problem

• Running bundle exec rubocop on a file that contained the following regex

/^[(]Correct answer(?:s*) (?:is|are) option(?:s)* ([\d]*)(?:, ([\d]*))*(?: and ([\d]*))*[)]$/

RuboCop version

$ [bundle exec] rubocop -V
0.93.0 (using Parser 2.7.2.0, rubocop-ast 0.7.1, running on ruby 2.6.6 x86_64-darwin18)

[martinjaimem]

@mnohai-mdsol I think this is already fixed on master branch

[marcandre]

Indeed, sorry about this bug. Fixed by #8863