From: "Eregon (Benoit Daloze) via ruby-core" <ruby-core@...>
Date: 2022-12-26T13:38:58+00:00
Subject: [ruby-core:111442] [Ruby master Bug#19259] `Data#with` doesn't call `initialize` nor `initialize_copy`

Issue #19259 has been updated by Eregon (Benoit Daloze).


My expectation is it would call `initialize` as well.
I didn't think about that in the review of https://github.com/ruby/ruby/pull/6766, sorry.
So like:
```ruby
class Data
  def with(**changes)
    self.class.new(**to_h.merge(changes))
  end
end
```

BTW, should `.new` be called dynamically too?

BTW ruby/spec's `mock/should_receive` should be useful to test whether initialize is called and with which arguments.

----------------------------------------
Bug #19259: `Data#with` doesn't call `initialize` nor `initialize_copy`
https://bugs.ruby-lang.org/issues/19259#change-100813

* Author: ko1 (Koichi Sasada)
* Status: Open
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
`Data#with` doesn't call `initialize` nor `initialize_copy`.
It is confirmation request.

```ruby
class P < Data.define(:x, :y)
  def initialize_copy(...)
    p :initialize_copy
    super
  end

  def initialize(...)
    p :initialize
    super
  end
end

pt = P.new(1, 2)
#=> :initialize
pt.clone
#=> :initialize_copy
pt.dup
#=> :initialize_copy
pt.with(x: 10)
#=> N/A
```

For example, if an author of `P` add validation code, `#with` skips it.



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