Class: RuboCop::Cop::Style::EachWithObject

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/style/each_with_object.rb

Overview

This cop looks for inject / reduce calls where the passed in object is returned at the end and so could be replace by each_with_object without the need to return the object at the end.

Examples:

# bad
[1, 2].inject({}) { |a, e| a[e] = e; a }

# good
[1, 2].each_with_object({}) { |e, a| a[e] = e }

Constant Summary collapse

MSG = 
'Use `each_with_object` instead of `%s`.'
METHODS = 
[:inject, :reduce]

Constants included from Util

Util::ASGN_NODES, Util::EQUALS_ASGN_NODES, Util::OPERATOR_METHODS, Util::PROC_NEW_NODE, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, #autocorrect?, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, cop_name_with_namespace, cop_type, #debug?, #display_cop_names?, inherited, #initialize, #join_force?, lint?, #message, non_rails, qualified_cop_name, rails?, #relevant_file?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, block_length, command?, comment_line?, const_name, first_part_of_call_chain, lambda?, lambda_or_proc?, line_range, numeric_range_size, on_node, operator?, parentheses?, proc?, range_with_surrounding_space, source_range, strip_quotes, within_node?

Methods included from PathUtil

issue_deprecation_warning, match_path?, relative_path

Constructor Details

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

Instance Method Details

#on_block(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/each_with_object.rb', line 20

def on_block(node)
  method, args, body = *node

  # filter out super and zsuper nodes
  return unless method.type == :send

  _, method_name, method_args = *method

  return unless METHODS.include? method_name
  return if method_args && method_args.type == :sym

  return_value = return_value(body)
  return unless return_value

  return unless first_argument_returned?(args, return_value)

  add_offense(method, :selector, format(MSG, method_name))
end