Class: RuboCop::Cop::Lint::StructNewOverride

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/lint/struct_new_override.rb

Overview

This cop checks unexpected overrides of the ‘Struct` built-in methods via `Struct.new`.

Examples:

# bad
Bad = Struct.new(:members, :clone, :count)
b = Bad.new([], true, 1)
b.members #=> [] (overriding `Struct#members`)
b.clone #=> true (overriding `Object#clone`)
b.count #=> 1 (overriding `Enumerable#count`)

# good
Good = Struct.new(:id, :name)
g = Good.new(1, "foo")
g.members #=> [:id, :name]
g.clone #=> #<struct Good id=1, name="foo">
g.count #=> 2

Constant Summary collapse

MSG = 
'`%<member_name>s` member overrides `Struct#%<method_name>s`' \
' and it may be unexpected.'
STRUCT_METHOD_NAMES = 
Struct.instance_methods
STRUCT_MEMBER_NAME_TYPES = 
%i[sym str].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, #disable_uncorrectable, #duplicate_location?, #excluded_file?, #external_dependency_checksum, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, #parse, qualified_cop_name, #reason_to_not_correct, #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?, #correctable?, #disable_offense, #disable_uncorrectable?, #safe_autocorrect?, #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/lint/struct_new_override.rb', line 36

def on_send(node)
  return unless struct_new(node) do
    node.arguments.each_with_index do |arg, index|
      # Ignore if the first argument is a class name
      next if index.zero? && arg.str_type?

      # Ignore if the argument is not a member name
      next unless STRUCT_MEMBER_NAME_TYPES.include?(arg.type)

      member_name = arg.value

      next unless STRUCT_METHOD_NAMES.include?(member_name.to_sym)

      message = format(MSG, member_name: member_name.inspect,
                            method_name: member_name.to_s)
      add_offense(arg, message: message)
    end
  end
end