Class: RuboCop::Cop::Style::UnpackFirst

Inherits:
Cop
  • Object
show all
Extended by:
TargetRubyVersion
Defined in:
lib/rubocop/cop/style/unpack_first.rb

Overview

This cop checks for accessing the first element of ‘String#unpack` which can be replaced with the shorter method `unpack1`.

Examples:


# bad
'foo'.unpack('h*').first
'foo'.unpack('h*')[0]
'foo'.unpack('h*').slice(0)
'foo'.unpack('h*').at(0)

# good
'foo'.unpack1('h*')

Constant Summary collapse

MSG = 
'Use `%<receiver>s.unpack1(%<format>s)` instead of '\
'`%<receiver>s.unpack(%<format>s)%<method>s`.'.freeze

Constants included from Util

Util::ASGN_NODES, Util::CONDITIONAL_NODES, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::LOGICAL_OPERATOR_NODES, Util::MODIFIER_NODES, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods included from TargetRubyVersion

minimum_target_ruby_version, support_target_ruby_version?

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, operator?, parentheses?, same_line?, to_string_literal, to_supported_styles, tokens

Methods included from PathUtil

absolute?, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

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

Instance Method Details

#autocorrect(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/unpack_first.rb', line 46

def autocorrect(node)
  unpack_and_first_element?(node) do |unpack_call, _unpack_arg|
    lambda do |corrector|
      corrector.remove(first_element_range(node, unpack_call))
      corrector.replace(unpack_call.loc.selector, 'unpack1')
    end
  end
end

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/unpack_first.rb', line 35

def on_send(node)
  unpack_and_first_element?(node) do |unpack_call, unpack_arg|
    range = first_element_range(node, unpack_call)
    message = format(MSG,
                     receiver:  unpack_call.receiver.source,
                     format: unpack_arg.source,
                     method: range.source)
    add_offense(node, message: message)
  end
end