From: andrew.kozin@...
Date: 2015-06-18T22:45:59+00:00
Subject: [ruby-core:69669] [Ruby trunk - Bug #11283] Block assigned	implicitly

Issue #11283 has been updated by Andrew Kozin.


I'd expect Ruby to do any of two options:

* Either provide a method with empty proc (`Proc.new`)
* Or call `SyntaxError` as a strict way to ask for the programmer's intention

I think any of these options could follow POLA better than the current one

----------------------------------------
Bug #11283: Block assigned implicitly
https://bugs.ruby-lang.org/issues/11283#change-53030

* Author: Andrew Kozin
* Status: Open
* Priority: Normal
* Assignee: 
* ruby -v: 1.9.3, 2.0, 2.1, 2.2, ruby-head
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
----------------------------------------
That is how it works:

    module Test
      def self.build(&block)
        klass = Class.new(Object)
        klass.__send__(:define_method, :foo)
        klass.__send__(:define_method, :bar)
        klass
      end
    end

    Tested = Test.build { :foo }
    # warning: tried to create Proc object without a block
    # => Tested
    Tested.new.foo
    # => :foo
    Tested.new.bar
    # => :foo

The block is assigned to all calls to `:define_method` via `Object#__send__` implicitly, while it wasn't asked to.

The behaviour is tested under MRI 1.9.3, 2.0, 2.1, 2.2, ruby-head. It doesn't occur under rbx-2 and jruby (1.7, 9.0.0.0).

For the context look at this thread https://github.com/mbj/mutant/issues/356



-- 
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