From: meanlogin@...
Date: 2014-09-24T23:57:25+00:00
Subject: [ruby-core:65263] [ruby-trunk - Bug #10293] [Open] splatting an empty hash in a method invocation sends an argument to the method (should send nothing)

Issue #10293 has been reported by First Last.

----------------------------------------
Bug #10293: splatting an empty hash in a method invocation sends an argument to the method (should send nothing)
https://bugs.ruby-lang.org/issues/10293

* Author: First Last
* Status: Open
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
* ruby -v: ruby 2.1.3p242 (2014-09-19 revision 47630) [x86_64-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
irb(main):001:0> def foo; end; foo **{}
ArgumentError: wrong number of arguments (1 for 0)

note that splatting an empty array results in no arguments

this behavior is particularly problematic with send (dispatching to different methods)

send method_name, *possibly_empty_arg_list, **possibly_empty_keyarg_hash

one should not have to do

if possibly_empty_keyarg_hash.empty?
  receiver.send method_name, *possibly_empty_arg_list
else  
  receiver.send method_name, *possibly_empty_arg_list, **possibly_empty_keyarg_hash
end

or

possibly_empty_arg_list << possibly_empty_keyarg_hash unless possibly_empty_keyarg_hash.empty?
receiver.send method_name, *possibly_empty_arg_list



-- 
https://bugs.ruby-lang.org/