Ruby 2.3 quirk in irb, pry, ripl (see https://twitter.com/josh_cheek/status/798658490235580416)

catted.log

$ cat test.rb | \irb
Switch to inspect mode.
true if 0...1
(irb):1: warning: integer literal in conditional range
(irb):1: warning: integer literal in conditional range
nil
true if 1..2
(irb):2: warning: integer literal in conditional range
(irb):2: warning: integer literal in conditional range
nil

$ cat test.rb | \pry
[1] pry(main)> true if 0...1
(pry):1: warning: integer literal in conditional range
(pry):1: warning: integer literal in conditional range
=> nil
[2] pry(main)> true if 1..2
(pry):2: warning: integer literal in conditional range
(pry):2: warning: integer literal in conditional range
=> nil
[3] pry(main)> 
$ cat test.rb | \ripl
>> true if 0...1
(ripl):1: warning: integer literal in conditional range
(ripl):1: warning: integer literal in conditional range
=> nil
>> true if 1..2
(ripl):2: warning: integer literal in conditional range
(ripl):2: warning: integer literal in conditional range
=> nil
>> 

manually.log

$ ruby -v
ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-linux]
$ \irb
irb(main):001:0> true if 0...1
(irb):1: warning: integer literal in conditional range
(irb):1: warning: integer literal in conditional range
=> nil
irb(main):002:0> true if 1..2
(irb):2: warning: integer literal in conditional range
(irb):2: warning: integer literal in conditional range
=> true
irb(main):003:0> 
$ \pry
[1] pry(main)> true if 0...1
(pry):1: warning: integer literal in conditional range
(pry):1: warning: integer literal in conditional range
=> nil
[2] pry(main)> true if 1..2
(pry):2: warning: integer literal in conditional range
(pry):2: warning: integer literal in conditional range
=> nil
[3] pry(main)> 
$ \ripl
>> true if 0...1
(ripl):1: warning: integer literal in conditional range
(ripl):1: warning: integer literal in conditional range
=> nil
>> true if 1..2
(ripl):2: warning: integer literal in conditional range
(ripl):2: warning: integer literal in conditional range
=> nil