Bug #10967
closedIs "warning: private attribute?" wrong?
Description
The following code ...
class Y
def initialize
@x = "ZOMG"
end
def print_x
puts x
end
private
attr_reader :x
end
Y.new.print_x
outputs ...
test.rb:12: warning: private attribute?
I tend to think this warning is wrong, I was surprised by https://github.com/rack/rack/pull/811 and I think this is a completely valid use case.
Also this code ...
class Y
def initialize
@x = "ZOMG"
end
def print_x
puts x
end
def assign_x
self.x = "ZOMG ZOMG"
end
private
attr_accessor :x
end
y = Y.new
y.assign_x
y.print_x
Works fine with warnings also. So a private writer works ok when the receiver is self
because Ruby has a special case for it, this make me think that private writers were thought to be used.
So ... am I wrong thinking that the warning should be removed or the self special case shouldn't work and be removed from Ruby code?. It doesn't make sense to me to have both things.
Updated by spastorino (Santiago Pastorino) over 9 years ago
One possible fix (the one removing the warning) ... https://github.com/ruby/ruby/pull/849
Updated by nobu (Nobuyoshi Nakada) over 9 years ago
- Description updated (diff)
It's valid in your case, but may not in others.
It doesn't sound enough reason to remove that warning to me.
If you want to suppress the warning, you can explicitly do it after the definition.
class Y
attr_writer :x
private :x=
end
Updated by marcandre (Marc-Andre Lafortune) over 9 years ago
FWIW, I feel that warning should be removed. There are too many false positives, and I suspect very very few cases where that warning is of any help. Note that without the warning, it will be obvious anyways when calling that reader/writer that it fails because it is private.
Updated by spastorino (Santiago Pastorino) over 9 years ago
There's also a discussion going on in another PR, https://github.com/ruby/ruby/pull/889
@nobu (Nobuyoshi Nakada), not sure what are the invalid use cases you refer to, and also what if I need to use let's say 2 private accessors? should I do ...
attr_accessor :a, :b
private :a, :a=, :b, :b=
Doesn't sound great to me.
Updated by matz (Yukihiro Matsumoto) over 9 years ago
We haven't thought of self as a receiver. Agreed to remove warnings.
Matz.
Updated by zzak (zzak _) over 9 years ago
- Status changed from Open to Closed
Applied in changeset r50585.
-
vm_method.c: Remove private attribute warning [Bug #10967]
Patch by @spastorino (Santiago Pastorino) [Fixes GH-849]
https://github.com/ruby/ruby/pull/849 -
test/ruby/test_module.rb: Update test for changes
Updated by usa (Usaku NAKAMURA) over 9 years ago
- Backport changed from 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN to 2.0.0: WONTFIX, 2.1: REQUIRED, 2.2: REQUIRED
Updated by usa (Usaku NAKAMURA) over 9 years ago
Is this a spec change or a bug?
Updated by nagachika (Tomoyuki Chikanaga) about 9 years ago
- Backport changed from 2.0.0: WONTFIX, 2.1: REQUIRED, 2.2: REQUIRED to 2.0.0: WONTFIX, 2.1: REQUIRED, 2.2: WONTFIX
Hmm, I don't know it's a bug fix or a spec change, but I think it's a trivial issue. I decided to not to backport to 2.2. Please notice if any objections.
Updated by usa (Usaku NAKAMURA) about 9 years ago
- Backport changed from 2.0.0: WONTFIX, 2.1: REQUIRED, 2.2: WONTFIX to 2.0.0: WONTFIX, 2.1: WONTFIX, 2.2: WONTFIX
Ok, I follow you, chikanaga-san!