Class: RuboCop::Cop::Performance::OpenStruct

Inherits:
Base
  • Object
show all
Defined in:
lib/rubocop/cop/performance/open_struct.rb

Overview

This cop checks for `OpenStruct.new` calls. Instantiation of an `OpenStruct` invalidates Ruby global method cache as it causes dynamic method definition during program runtime. This could have an effect on performance, especially in case of single-threaded applications with multiple `OpenStruct` instantiations.

Examples:

# bad
class MyClass
  def my_method
    OpenStruct.new(my_key1: 'my_value1', my_key2: 'my_value2')
  end
end

# good
class MyClass
  MyStruct = Struct.new(:my_key1, :my_key2)
  def my_method
    MyStruct.new('my_value1', 'my_value2')
  end
end

Constant Summary collapse

MSG =
'Consider using `Struct` over `OpenStruct` ' \
'to optimize the performance.'
RESTRICT_ON_SEND =
%i[new].freeze

Instance Method Summary collapse

Instance Method Details

#on_send(node) ⇒ Object


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# File 'lib/rubocop/cop/performance/open_struct.rb', line 39

def on_send(node)
  open_struct(node) do
    add_offense(node.loc.selector)
  end
end