Bug #12684: Delegator#eql? missing

• Status: Closed
• Assignee: nobu (Nobuyoshi Nakada)
• Target version: -
• ruby -v: 2.3.1
• Backport: 2.2: REQUIRED, 2.3: REQUIRED, 2.4: WONTFIX

[carsonreinke (Carson Reinke)]

There is some strange behavior because Delegator is missing an alias of #eql? to #==

2.3.1 :001 > s = 'test'
 => "test" 
2.3.1 :002 > d = SimpleDelegator.new(s)
 => "test" 
2.3.1 :003 > d.eql?(d)
 => false 
2.3.1 :004 > d == d
 => true 
2.3.1 :005 > d.hash == d.hash
 => true

I understand that Delegator is a BasicObject and that does not define #eql? method, but this method is being used by Arrayr.

For example,

2.3.1 :001 > s = 'test'
 => "test" 
2.3.1 :002 > a = [SimpleDelegator.new(s), SimpleDelegator.new(s)]
 => ["test", "test"] 
2.3.1 :003 > a[0] == a[1]
 => true 
2.3.1 :004 > a.uniq()
 => ["test", "test"]
2.3.1 :005 > a[0].hash == a[1].hash
 => true

Kind of strange behavior, especially reading the documentation.

Now maybe, Array#uniq should be changed to use #== instead of #eql?

[giginet (Kohki Miki)]

I fixed this issue and I added the specs.
Could you check it?

https://github.com/ruby/ruby/pull/1564
https://github.com/ruby/spec/pull/399

[nobu (Nobuyoshi Nakada)]

• Description updated (diff)
• Backport changed from 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN to 2.2: REQUIRED, 2.3: REQUIRED, 2.4: REQUIRED

Seems fine.

[ko1 (Koichi Sasada)]

• Assignee set to nobu (Nobuyoshi Nakada)

[Eregon (Benoit Daloze)]

@nobu (Nobuyoshi Nakada) Any update on this? I think your patch is OK.

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset trunk|r59167.

---

Delegate to eql? [Fix GH-1564]

• lib/delegate.rb (eql?): Delegate to eql? of the inner object.
  based on the patch by giginet [e-mail].
  [ruby-core:76950] [Bug #12684]

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.2: REQUIRED, 2.3: REQUIRED, 2.4: REQUIRED to 2.2: REQUIRED, 2.3: REQUIRED, 2.4: WONTFIX

I think this is a spec change because of existence of the test in rubyspec about this behavior.
I will change WONTFIX for 2.4. Please tell us if there are any real world application suffered with this issue.