From: merch-redmine@...
Date: 2019-09-02T04:33:17+00:00
Subject: [ruby-core:94716] [Ruby master Bug#10293] splatting an empty hash in a method invocation sends an argument to the method (should send nothing)

Issue #10293 has been updated by jeremyevans0 (Jeremy Evans).

Status changed from Assigned to Closed

With the acceptance of #14183, double splatting an empty hash no longer sends an empty positional hash to the method.

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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#change-81327

* Author: rits (First Last)
* Status: Closed
* Priority: Normal
* Assignee: nobu (Nobuyoshi Nakada)
* Target version: 
* ruby -v: ruby 2.1.3p242 (2014-09-19 revision 47630) [x86_64-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: REQUIRED
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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



-- 
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