Bug #2147: Cannot pp DelegateClass derived classes: undefined method `inspect' NameError

• Status: Closed
• Assignee: -
• ruby -v: ruby 1.9.1p243 (2009-07-16 revision 24175) [i686-linux]

[pilcrow (Mike Pomraning)]

=begin
pp derived_from_delegate_class fails with a NameError under 1.9.1, apparently unable to find the method #inspect(), though a direct call to that method works fine:

=== begin ===
require 'delegate'
require 'pp'

class A < DelegateClass(Array); end

puts "ruby-#{RUBY_VERSION}-p#{RUBY_PATCHLEVEL} (#{RUBY_PLATFORM})"
puts A.new([]).inspect
pp A.new([])
=== end ===

Compare:

$ ruby-1.8.7 delegate-inspect.rb
ruby-1.8.7-p160 (i686-linux)
[]
[]

$ ruby-1.9 delegate-inspect.rb
ruby-1.9.1-p243 (i686-linux)
[]
/opt/ruby-1.9.1/lib/ruby/1.9.1/pp.rb:286:in method': undefined method inspect' for class A' (NameError) from /opt/ruby-1.9.1/lib/ruby/1.9.1/pp.rb:286:in call'
from /opt/ruby-1.9.1/lib/ruby/1.9.1/pp.rb:286:in pretty_print' from /opt/ruby-1.9.1/lib/ruby/1.9.1/pp.rb:154:in block in pp'
from /opt/ruby-1.9.1/lib/ruby/1.9.1/prettyprint.rb:200:in block (2 levels) in group' from /opt/ruby-1.9.1/lib/ruby/1.9.1/prettyprint.rb:227:in nest'
from /opt/ruby-1.9.1/lib/ruby/1.9.1/prettyprint.rb:200:in block in group' from /opt/ruby-1.9.1/lib/ruby/1.9.1/prettyprint.rb:212:in group_sub'
from /opt/ruby-1.9.1/lib/ruby/1.9.1/prettyprint.rb:199:in group' from /opt/ruby-1.9.1/lib/ruby/1.9.1/pp.rb:154:in pp'
from /opt/ruby-1.9.1/lib/ruby/1.9.1/pp.rb:77:in block in pp' from /opt/ruby-1.9.1/lib/ruby/1.9.1/pp.rb:121:in guard_inspect_key'
from /opt/ruby-1.9.1/lib/ruby/1.9.1/pp.rb:77:in pp' from /opt/ruby-1.9.1/lib/ruby/1.9.1/pp.rb:59:in block in pp'
from /opt/ruby-1.9.1/lib/ruby/1.9.1/pp.rb:59:in each' from /opt/ruby-1.9.1/lib/ruby/1.9.1/pp.rb:59:in pp'
from delegate-inspect.rb:8:in `'
=end

[pilcrow (Mike Pomraning)]

=begin
This is also a problem unit testing anything derived from DelegateClass: AssertionMessage.delayed_diff calls a method, convert(), which may call pp, meaning that something as simple as:

assert_equal [1,2,3], array_like_derived_from_delegateclass

will fail with an internal NameError (!).
=end

[yugui (Yuki Sonoda)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

=begin
This issue was solved with changeset r25951.
Mike, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

=end