[ruby-core:111534] [Ruby master Bug#19278] Constructing subclasses of Data with positional arguments

Issue #19278 has been updated by Eregon (Benoit Daloze).


To clarify:

> Also inheriting from a Data class seems kind of an anti/rare pattern.

I meant one should use `Struct.new(...) { ... }` / `Data.define(...) { ... }` and not `class < Struct.new(...)` / `class < Data.define(...)` which is wasteful because it creates an extra class and makes the hierarchy needlessly one level deeper (and also causes an unnamed supercass).

----------------------------------------
Bug #19278: Constructing subclasses of Data with positional arguments
https://bugs.ruby-lang.org/issues/19278#change-100897

* Author: tenderlovemaking (Aaron Patterson)
* Status: Feedback
* Priority: Normal
* ruby -v: ruby 3.2.0 (2022-12-25 revision a528908271) [arm64-darwin22]
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN
----------------------------------------
I'd expect both of the following subclasses to work, but the subclass that uses positional parameters raises an exception:

```ruby
Foo = Data.define

class Bar < Foo
  def initialize foo:
    p foo
  end
end

class Baz < Foo
  def initialize foo
    p foo
  end
end

Bar.new foo: 1 # Prints 1
Baz.new 1    # Raises ArgumentError
```

I'd expect the subclass that uses positional arguments to work.



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