Issue #21029 has been updated by S_H_ (Shun Hiraoka). I agree that consistent behavior between both cases would be ideal. Given the current structure of `parse.y`, wrapping with `NODE_BLOCK` seems like the most straightforward approach to make both `defined?(;x)` and `defined?(x;)` return `"expression"`. With my current changes, both forms now generate the same AST nodes, which I believe improves consistency across the board. Also, I want to clarify my earlier comment about being "skeptical" — I was specifically referring to adding new parameters to the `parser_params` struct, not to the `NODE_BLOCK` wrapping approach itself. Sorry for any confusion caused. Right now, the `defined?(x;)` test is failing on `parse.y`, which makes it hard to assess whether changes to `universal_parser.c` or other components are affecting the `parse.y` behavior. This adds friction when trying to work on parser-related modifications. From a maintenance standpoint, I believe fixing this failing test would help ensure that future `parse.y` changes can be validated more reliably. Would you be open to keeping this change in order to maintain test consistency? ---------------------------------------- Bug #21029: Prism behavior for `defined? (;x)` differs https://bugs.ruby-lang.org/issues/21029#change-114022 * Author: qnighy (Masaki Hara) * Status: Closed * ruby -v: ruby 3.5.0dev (2025-01-11T03:21:57Z master 1b3037081e) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Prism has a different behavior for `(;expr)` when used in `defined?` predicate: ```console % ./miniruby --parser=prism -e "p defined? (;x)" nil % ./miniruby --parser=parse.y -e "p defined? (;x)" "expression" ``` Although not a significant difference, aligning either of them with the other would be better. -- https://bugs.ruby-lang.org/