Issue #19520 has been updated by Eregon (Benoit Daloze). In fact, implementing `labeled_module`/`labeled_class` like you showed above would again break these expectations, illustrating how unsafe is this API, and it's clear many people writing such tests wouldn't realize this problem (they might not even know the `labeled_module` implementation change). E.g. there are some `m = labeled_module("M")` and some `c0 = EnvUtil.labeled_class('C0') do`, but of course no constant `M` or `C0`. ---------------------------------------- Feature #19520: Support for `Module.new(name)` and `Class.new(superclass, name)`. https://bugs.ruby-lang.org/issues/19520#change-102413 * Author: ioquatix (Samuel Williams) * Status: Open * Priority: Normal ---------------------------------------- See <https://bugs.ruby-lang.org/issues/19450> for previous discussion and motivation. [This proposal](https://github.com/ruby/ruby/pull/7376) introduces the `name` parameter to `Class.new` and `Module.new`: ```ruby Class.new(superclass, name) Module.new(name) ``` As a slight change, we could use keyword arguments instead. ## Example usage The current Ruby test suite has code which shows the usefulness of this new method: ```ruby def labeled_module(name, &block) Module.new do singleton_class.class_eval { define_method(:to_s) {name} alias inspect to_s alias name to_s } class_eval(&block) if block end end module_function :labeled_module def labeled_class(name, superclass = Object, &block) Class.new(superclass) do singleton_class.class_eval { define_method(:to_s) {name} alias inspect to_s alias name to_s } class_eval(&block) if block end end module_function :labeled_class ``` The updated code would look like this: ```ruby def labeled_module(name, &block) Module.new(name, &block) end def labeled_class(name, superclass = Object, &block) Class.new(superclass, name, &block) end module_function :labeled_class ``` -- https://bugs.ruby-lang.org/