Fix Ruby warnings

[bkuhlmann]

Why

Hello. 👋

I'm seeing the following warnings pop up when running specs, jumping into the IRB console, etc:

irb(main):001> /usr/local/bundle/gems/prism-1.9.0/lib/prism/visitor.rb:480: warning: the block passed to 'Prism::StringNode#each_child_node' defined at /usr/local/bundle/gems/prism-1.9.0/lib/prism/node.rb:18140 may be ignored
/usr/local/bundle/gems/prism-1.9.0/lib/prism/visitor.rb:595: warning: the block passed to 'Prism::NilNode#each_child_node' defined at /usr/local/bundle/gems/prism-1.9.0/lib/prism/node.rb:14497 may be ignored
/usr/local/bundle/gems/prism-1.9.0/lib/prism/visitor.rb:265: warning: the block passed to 'Prism::ConstantReadNode#each_child_node' defined at /usr/local/bundle/gems/prism-1.9.0/lib/prism/node.rb:6015 may be ignored
/usr/local/bundle/gems/prism-1.9.0/lib/prism/visitor.rb:770: warning: the block passed to 'Prism::SymbolNode#each_child_node' defined at /usr/local/bundle/gems/prism-1.9.0/lib/prism/node.rb:18481 may be ignored
/usr/local/bundle/gems/prism-1.9.0/lib/prism/visitor.rb:535: warning: the block passed to 'Prism::LocalVariableReadNode#each_child_node' defined at /usr/local/bundle/gems/prism-1.9.0/lib/prism/node.rb:12910 may be ignored

How

This seemed to crop up with Prism 1.9.0 and can be seen when warnings are enabled (i.e. export RUBYOPT="-W:deprecated -W:performance -W:strict_unused_block"). Resolving these warnings, especially, clean up the verbosity of IRB output each time you try to evaluate Ruby code.

Notes

• macOS: macOS 26.3.1
• Ruby: ruby 4.0.2 (2026-03-17 revision d3da9fec82) +YJIT +PRISM [arm64-darwin25.3.0]
• Prism: 1.9.0

[Earlopain]

Hi there, this is already (accidentally) fixed on main. In #3933 we added explicit block arguments to these methods

[eregon]

Might be good to add a test for this to ensure it doesn't regress.
Or maybe the existing type tests would already catch such cases?

[Earlopain]

What test specifically do you have in mind? We must be careful to only do this in ruby/prism and not change global warning settings in ruby/ruby. I do think that current typechecking will probably prevent this.

[eregon]

I'm thinking a run of tests in CI with these flags (or Warning[category] = true) + defining Warning.warn as raise, probably activated via some env var or so.
Could be enabled by default in ruby/prism's CI.