Lint/AmbiguousRegexpLiteral: undefined method `receiver' for nil:NilClass

[deepj]

---

Expected behavior

This code does not cause the described error below.

class EventTest < ActiveSupport::TestCase
  test '#call' do
    assert_match /confirmed order/, event.description
  end
end

Actual behavior

I got this error:

Inspecting 1 file
Scanning ~/event_test.rb
An error occurred while Lint/AmbiguousRegexpLiteral cop was inspecting ~/event_test.rb.
undefined method `receiver' for nil:NilClass
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:64:in `method_chain_to_regexp_receiver?'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:56:in `find_offense_node'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:50:in `find_offense_node_by'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:35:in `block in on_new_investigation'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:32:in `each'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/lint/ambiguous_regexp_literal.rb:32:in `on_new_investigation'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:143:in `block (2 levels) in invoke'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:152:in `with_cop_error_handling'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:142:in `block in invoke'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:141:in `each'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:141:in `invoke'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/commissioner.rb:83:in `investigate'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/team.rb:152:in `investigate_partial'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cop/team.rb:83:in `investigate'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:315:in `inspect_file'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:259:in `block in do_inspection_loop'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:293:in `block in iterate_until_no_changes'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:286:in `loop'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:286:in `iterate_until_no_changes'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:255:in `do_inspection_loop'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:132:in `block in file_offenses'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:157:in `file_offense_cache'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:131:in `file_offenses'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:122:in `process_file'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:101:in `block in each_inspected_file'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:100:in `each'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:100:in `reduce'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:100:in `each_inspected_file'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:86:in `inspect_files'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/runner.rb:47:in `run'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cli/command/execute_runner.rb:25:in `execute_runner'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cli/command/execute_runner.rb:17:in `run'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cli/command.rb:11:in `run'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cli/environment.rb:18:in `run'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cli.rb:65:in `run_command'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cli.rb:72:in `execute_runners'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/lib/rubocop/cli.rb:41:in `run'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/exe/rubocop:13:in `block in <top (required)>'
~/.rubies/ruby-2.7.1/lib/ruby/2.7.0/benchmark.rb:308:in `realtime'
~/.gem/ruby/2.7.1/gems/rubocop-0.93.0/exe/rubocop:12:in `<top (required)>'
~/.gem/ruby/2.7.1/bin/rubocop:23:in `load'
~/.gem/ruby/2.7.1/bin/rubocop:23:in `<main>'

Steps to reproduce the problem

rubocop -d event_test.rb --only Lint/AmbiguousRegexpLiteral

RuboCop version

$ rubocop -V
0.93.0 (using Parser 2.7.2.0, rubocop-ast 0.7.1, running on ruby 2.7.1 x86_64-darwin18)

[marcandre]

Note: there's already an open PR for this cop: #8708

[koic]

This issue is a recent regression by #8847 💦