Error: undefined method `node_type' for nil:NilClass case value.node_type

[tim-heinsohn]

Background

Brakeman version: 6.0.1
Rails version: 7.0.4.3
Ruby version: 3.1.4p223

Issue

When running brakeman --debug . I get the following error:

Error: undefined method `node_type' for nil:NilClass          case value.node_type                   ^^^^^^^^^^
Location: /home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/tracker/controller.rb:126:in `before_filter_to_hash'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/tracker/controller.rb:93:in `block in get_before_filters'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/tracker/controller.rb:92:in `each'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/tracker/controller.rb:92:in `get_before_filters'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/tracker/controller.rb:44:in `before_filter_list'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/processors/controller_alias_processor.rb:239:in `before_filter_list'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/processors/controller_alias_processor.rb:95:in `block in process_defn'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/processors/alias_processor.rb:523:in `block in meth_env'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/bundle/ruby/3.1.0/gems/sexp_processor-4.17.0/lib/sexp_processor.rb:452:in `scope'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/processors/alias_processor.rb:520:in `meth_env'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/processors/controller_alias_processor.rb:93:in `process_defn'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/ruby_parser/bm_sexp_processor.rb:76:in `block in process'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/ruby_parser/bm_sexp_processor.rb:113:in `in_context'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/ruby_parser/bm_sexp_processor.rb:72:in `process'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/processors/alias_processor.rb:62:in `block in process_default'
(eval):3:in `map!'
(eval):3:in `map!'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/processors/alias_processor.rb:60:in `process_default'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/processors/controller_alias_processor.rb:31:in `process_controller'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/processor.rb:50:in `process_controller_alias'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/scanner.rb:280:in `block (2 levels) in process_controller_data_flows'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/scanner.rb:279:in `each'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/scanner.rb:279:in `block in process_controller_data_flows'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/scanner.rb:341:in `block in track_progress'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/scanner.rb:338:in `each'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/scanner.rb:338:in `track_progress'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/scanner.rb:277:in `process_controller_data_flows'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/scanner.rb:66:in `process'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman.rb:392:in `scan'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman.rb:86:in `run'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/commandline.rb:157:in `run_brakeman'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/commandline.rb:125:in `regular_report'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/commandline.rb:166:in `run_report'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/commandline.rb:35:in `run'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/lib/brakeman/commandline.rb:20:in `start'
/home/t/.rvm/gems/ruby-3.1.4/gems/brakeman-6.0.1/bin/brakeman:10:in `<top (required)>'
/home/t/.rvm/gems/ruby-3.1.4/bin/brakeman:25:in `load'
/home/t/.rvm/gems/ruby-3.1.4/bin/brakeman:25:in `<main>'
/home/t/.rvm/gems/ruby-3.1.4/bin/ruby_executable_hooks:22:in `eval'
/home/t/.rvm/gems/ruby-3.1.4/bin/ruby_executable_hooks:22:in `<main>'

in

brakeman/lib/brakeman/tracker/controller.rb

Line 126 in ccdb7eb

case value.node_type

Using safe navigation seems to resolve the issue:

        case value&.node_type

but I'm not filing a PR as I'm not sure what the code is doing.

The args leading to the error look like this:

[1] pry(#<Brakeman::Controller>)> args
=> s(s(:lit, :fake_filter8984522737743934), s(:hash, s(:kwsplat, s(:lvar, :options))))

[tim-heinsohn]

I get the same error with Brakeman 5.2.1, so probably a local / rvm issue.

[presidentbeef]

Hi @tqmz - wow this is some old Brakeman code that was written well before keyword splats existed in Ruby 😄

[tim-heinsohn]

Nice @presidentbeef, thanks! (Will there be a patch release?)

[presidentbeef]

Yes, soon... 🤞