Crash with some formatters in v1.63.2

[verdammelt]

After upgrading to v1.63.2 from 1.62.1 I found that the default formatter resulted in a crash:

...
142 files inspected, 135 offenses detected, 105 offenses autocorrectable
index 0 outside of array bounds: 0...0
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/parser-3.3.0.5/lib/parser/source/buffer.rb:274:in `fetch'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/parser-3.3.0.5/lib/parser/source/buffer.rb:274:in `source_line'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/parser-3.3.0.5/lib/parser/source/range.rb:126:in `source_line'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/formatter/clang_style_formatter.rb:34:in `valid_line?'
...

I went through all the documented formatters and found the following results:

| formatter   | crash? |
|-------------+--------|
| autogenconf | no     |
| clang       | yes    |
| emacs       | no     |
| files       | no     |
| fuubar      | yes    |
| github      | no     |
| html        | yes    |
| json        | no     |
| junit       | no     |
| markdown    | yes    |
| offenses    | no     |
| pacman      | yes    |
| progress    | yes    |
| quiet       | no     |
| simple      | no     |
| tap         | yes    |
| worst       | no     |

I then spot checked clang and markdown in previous versions. I found that clang started failing in 1.63.1 while markdown was failing since at least 1.62.1

Expected behavior

I expect rubocop not to crash when using some formatters.

Actual behavior

(not including --debug output here as the file is 2.1Mb... but I can provide that data if needed)

Rubocop will run and report errors for a while and then crash with an error: index 0 outside of array bounds: 0...0 and a stack trace:

/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/parser-3.3.0.5/lib/parser/source/buffer.rb:274:in `fetch'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/parser-3.3.0.5/lib/parser/source/buffer.rb:274:in `source_line'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/parser-3.3.0.5/lib/parser/source/range.rb:126:in `source_line'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/formatter/clang_style_formatter.rb:34:in `valid_line?'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/formatter/clang_style_formatter.rb:27:in `report_offense'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/formatter/clang_style_formatter.rb:12:in `block in report_file'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/formatter/clang_style_formatter.rb:12:in `each'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/formatter/clang_style_formatter.rb:12:in `report_file'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/formatter/simple_text_formatter.rb:33:in `file_finished'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/formatter/formatter_set.rb:51:in `block in file_finished'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/formatter/formatter_set.rb:51:in `each'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/formatter/formatter_set.rb:51:in `file_finished'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/runner.rb:250:in `file_finished'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/runner.rb:162:in `process_file'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/runner.rb:138:in `block in each_inspected_file'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/runner.rb:137:in `each'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/runner.rb:137:in `reduce'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/runner.rb:137:in `each_inspected_file'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/runner.rb:123:in `inspect_files'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/runner.rb:76:in `run'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/cli/command/execute_runner.rb:26:in `block in execute_runner'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/cli/command/execute_runner.rb:52:in `with_redirect'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/cli/command/execute_runner.rb:25:in `execute_runner'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/cli/command/execute_runner.rb:17:in `run'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/cli/command.rb:11:in `run'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/cli/environment.rb:18:in `run'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/cli.rb:118:in `run_command'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/cli.rb:125:in `execute_runners'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/cli.rb:51:in `block in run'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/cli.rb:77:in `profile_if_needed'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/lib/rubocop/cli.rb:43:in `run'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/exe/rubocop:19:in `block in <top (required)>'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/benchmark.rb:311:in `realtime'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/rubocop-1.63.2/exe/rubocop:19:in `<top (required)>'
/Users/mark/.rbenv/versions/3.1.3/bin/rubocop:25:in `load'
/Users/mark/.rbenv/versions/3.1.3/bin/rubocop:25:in `<top (required)>'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/bundler/cli/exec.rb:58:in `load'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/bundler/cli/exec.rb:58:in `kernel_load'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/bundler/cli/exec.rb:23:in `run'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/bundler/cli.rb:486:in `exec'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/bundler/vendor/thor/lib/thor/invocation.rb:127:in `invoke_command'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/bundler/vendor/thor/lib/thor.rb:392:in `dispatch'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/bundler/cli.rb:31:in `dispatch'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/bundler/vendor/thor/lib/thor/base.rb:485:in `start'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/bundler/cli.rb:25:in `start'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/bundler-2.3.26/libexec/bundle:48:in `block in <top (required)>'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/3.1.0/bundler/friendly_errors.rb:120:in `with_friendly_errors'
/Users/mark/.rbenv/versions/3.1.3/lib/ruby/gems/3.1.0/gems/bundler-2.3.26/libexec/bundle:36:in `<top (required)>'
/Users/mark/.rbenv/versions/3.1.3/bin/bundle:25:in `load'
/Users/mark/.rbenv/versions/3.1.3/bin/bundle:25:in `<main>'

Most of the tested formatters that failed did have this failure coming from clang_style_formatter but markdown and html have failures starting in their formatters.

Steps to reproduce the problem

I am unsure which rule is triggering the failure but it seems that most commonly the error seen just before the crash is: Lint/EmptyFile: Empty file detected.

RuboCop version

> bundle exec rubocop -V
1.63.2 (using Parser 3.3.0.5, rubocop-ast 1.31.2, running on ruby 3.1.3) [arm64-darwin22]
  - rubocop-capybara 2.20.0
  - rubocop-factory_bot 2.25.1
  - rubocop-rails 2.24.1
  - rubocop-rake 0.6.0
  - rubocop-rspec 2.29.1

[verdammelt]

I noticed when looking at the --debug output that the file with the Lint/EmptyFile error was being loaded from the rubocop cache. So I turned off the cache and rubocop ran successfully to completion.

So it would seem that perhaps this is problem with the data I have in my cache.

Is that sufficient resolution to this? Shall I just close the issue?

The contents of that cached file is:
[{"severity":"warning","location":{"begin_pos":0,"end_pos":0},"message":"Lint/EmptyFile: Empty file detected.","cop_name":"Lint/EmptyFile","status":"unsupported"}]

[Earlopain]

I can reproduce this by creating a new empty file and running rubocop on it twice. Only the second run will error. Lint/EmptyFile creates a global offense which I presume doesn't roundtrip well. This is now exposed because of #12804.

[verdammelt]

@Earlopain interestingly (to me at least) This problem only happens when caching is involved.

I moved aside my cache directory and ran rubocop with the debug flag. It ran fine and I could see my empty file was being scanned. I ran a few more times immediately and the next 2 or 3 times the file was still scanned but then the file was being picked up by the cache and rubocop was crashing.

[Earlopain]

Check out the attached PR, that should fix this. Let me know if that works for you.

[verdammelt]

Check out the attached PR, that should fix this. Let me know if that works for you.

This does appear to correct the problem.