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

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
RangeHelp
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 replaced by each_with_object without the need to return the object at the end.

However, we can’t replace with each_with_object if the accumulator parameter is assigned to within the block.

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 `%<method>s`.'
METHODS = 
%i[inject reduce].freeze

Constants inherited from Base

Base::RESTRICT_ON_SEND

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods inherited from Base

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

add_parentheses, args_begin, args_end, begins_its_line?, comment_line?, comment_lines?, double_quotes_required?, escape_string, first_part_of_call_chain, indent, interpret_string_escapes, line_range, needs_escaping?, on_node, parentheses?, same_line?, to_string_literal, to_supported_styles, trim_string_interporation_escape_character

Methods included from PathUtil

absolute?, hidden_dir?, hidden_file?, hidden_file_in_not_hidden_dir?, match_path?, maybe_hidden_file?, relative_path, smart_path

Constructor Details

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

Instance Method Details

#on_block(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/each_with_object.rb', line 30

def on_block(node)
  each_with_object_candidate?(node) do |method, args, body|
    _, method_name, method_arg = *method
    return if simple_method_arg?(method_arg)

    return_value = return_value(body)
    return unless return_value
    return unless first_argument_returned?(args, return_value)
    return if accumulator_param_assigned_to?(body, args)

    message = format(MSG, method: method_name)
    add_offense(method.loc.selector, message: message) do |corrector|
      autocorrect(corrector, node, return_value)
    end
  end
end