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

Inherits:
Cop
  • 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.'.freeze

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, autocorrect_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, #correct, department, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from AST::Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, parentheses?, same_line?, to_string_literal, to_supported_styles, tokens, trim_string_interporation_escape_character

Methods included from PathUtil

absolute?, chdir, hidden_dir?, hidden_file_in_not_hidden_dir?, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

This class inherits a constructor from RuboCop::Cop::Cop

Instance Method Details

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/performance/open_struct.rb', line 38

def on_send(node)
  open_struct(node) do |method|
    add_offense(node, location: :selector, message: format(MSG, method))
  end
end