v0.3: Support frozen-string-literal coexistence

[miry]

The current version of master returns with next error when use RUBYOPT="--enable=frozen-string-literal".

$ RUBYOPT="--enable=frozen-string-literal" bundle exec ruby examples/adder/adder.rb
/Users/miry/src/wouterken/crystalruby/lib/crystalruby/source_reader.rb:48:in `node_to_s': undefined method `accept' for nil (NoMethodError)

      SyntaxTree::Formatter.format("", node.accept(@visitor))
                                           ^^^^^^^
	from /Users/miry/src/wouterken/crystalruby/lib/crystalruby/source_reader.rb:73:in `extract_args_and_source_from_method'
	from /Users/miry/src/wouterken/crystalruby/lib/crystalruby/adapter.rb:178:in `define_crystalized_method'
	from /Users/miry/src/wouterken/crystalruby/lib/crystalruby/adapter.rb:108:in `method_added'
	from examples/adder/adder.rb:5:in `<module:Adder>'
	from examples/adder/adder.rb:3:in `<main>'

Debugging:

SyntaxTree.search(method_source, :Params).first returns nil

Note: It worked for 0.2.3

[miry]

I am not an expert, I think https://github.com/ruby/prism should work for parsing Ruby code.

[miry]

I run some tests in SyntaxTree https://github.com/miry/syntax_tree/actions/runs/12072657747/job/33667110520, it seems it does not work well with latest ruby version.

[wouterken]

Thanks @miry
I've switched to prism for Ruby parsing in 0.3.1, and now it seems to run without issues when RUBYOPT="--enable=frozen-string-literal"

🙏