Layout/EmptyLinesAroundAttributeAccessor fails if the attr_accessor is the last line of the file

[tas50]

Expected behavior

EOF should be considered an empty line around the attr_accessor and the cop should continue on without error.

Actual behavior

An error occurred while Layout/EmptyLinesAroundAttributeAccessor cop was inspecting /Users/tsmith/dev/the_world/php5-fpm/resources/pool.rb:66:0.
undefined method `blank?' for nil:NilClass
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/layout/empty_lines_around_attribute_accessor.rb:87:in `next_line_empty?'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/layout/empty_lines_around_attribute_accessor.rb:72:in `on_send'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/commissioner.rb:100:in `public_send'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/commissioner.rb:100:in `block (2 levels) in trigger_responding_cops'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/commissioner.rb:166:in `with_cop_error_handling'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/commissioner.rb:99:in `block in trigger_responding_cops'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/commissioner.rb:98:in `each'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/commissioner.rb:98:in `trigger_responding_cops'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/commissioner.rb:69:in `on_send'
/usr/local/lib/ruby/gems/2.7.0/gems/rubocop-ast-1.3.0/lib/rubocop/ast/traversal.rb:136:in `block in on_dstr'
/usr/local/lib/ruby/gems/2.7.0/gems/rubocop-ast-1.3.0/lib/rubocop/ast/traversal.rb:136:in `each'
/usr/local/lib/ruby/gems/2.7.0/gems/rubocop-ast-1.3.0/lib/rubocop/ast/traversal.rb:136:in `on_dstr'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/commissioner.rb:71:in `on_begin'
/usr/local/lib/ruby/gems/2.7.0/gems/rubocop-ast-1.3.0/lib/rubocop/ast/traversal.rb:20:in `walk'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/commissioner.rb:86:in `investigate'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/team.rb:157:in `investigate_partial'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cop/team.rb:83:in `investigate'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:315:in `inspect_file'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:259:in `block in do_inspection_loop'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:293:in `block in iterate_until_no_changes'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:286:in `loop'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:286:in `iterate_until_no_changes'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:255:in `do_inspection_loop'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:132:in `block in file_offenses'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:157:in `file_offense_cache'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:131:in `file_offenses'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:122:in `process_file'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:101:in `block in each_inspected_file'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:100:in `each'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:100:in `reduce'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:100:in `each_inspected_file'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:86:in `inspect_files'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/runner.rb:47:in `run'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cli/command/execute_runner.rb:26:in `block in execute_runner'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cli/command/execute_runner.rb:52:in `with_redirect'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cli/command/execute_runner.rb:25:in `execute_runner'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cli/command/execute_runner.rb:17:in `run'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cli/command.rb:11:in `run'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cli/environment.rb:18:in `run'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cli.rb:65:in `run_command'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cli.rb:72:in `execute_runners'
/Users/tsmith/dev/oss/rubocop/lib/rubocop/cli.rb:41:in `run'
/Users/tsmith/dev/oss/rubocop/exe/rubocop:13:in `block in <top (required)>'
/usr/local/Cellar/ruby/2.7.2/lib/ruby/2.7.0/benchmark.rb:308:in `realtime'
/Users/tsmith/dev/oss/rubocop/exe/rubocop:12:in `<top (required)>'
/usr/local/lib/ruby/gems/2.7.0/bin/rubocop:23:in `load'
/usr/local/lib/ruby/gems/2.7.0/bin/rubocop:23:in `<top (required)>'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/cli/exec.rb:63:in `load'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/cli/exec.rb:63:in `kernel_load'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/cli/exec.rb:28:in `run'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/cli.rb:476:in `exec'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/vendor/thor/lib/thor/invocation.rb:127:in `invoke_command'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/vendor/thor/lib/thor.rb:399:in `dispatch'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/cli.rb:30:in `dispatch'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/vendor/thor/lib/thor/base.rb:476:in `start'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/cli.rb:24:in `start'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/exe/bundle:46:in `block in <top (required)>'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/friendly_errors.rb:123:in `with_friendly_errors'
/usr/local/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/exe/bundle:34:in `<top (required)>'
/usr/local/opt/ruby/bin/bundle:23:in `load'
/usr/local/opt/ruby/bin/bundle:23:in `<main>'

Steps to reproduce the problem

End a file with the attr_accessor like this

# whatever
attr_accessor :exists

RuboCop version

1.5.2 (using Parser 2.7.2.0, rubocop-ast 1.3.0, running on ruby 2.7.2 x86_64-darwin19)
  - rubocop-performance 1.9.1
  - rubocop-rspec 2.0.1