Class: RuboCop::Cop::Style::Lambda

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

Overview

This cop checks for uses of the pre 1.9 lambda syntax for one-line anonymous functions and uses of the 1.9 lambda syntax for multi-line anonymous functions.

Constant Summary collapse

SINGLE_MSG =
'Use the new lambda literal syntax `->(params) {...}`.'
SINGLE_NO_ARG_MSG =
'Use the new lambda literal syntax `-> {...}`.'
MULTI_MSG =
'Use the `lambda` method for multi-line lambdas.'
TARGET =
s(:send, nil, :lambda)

Constants included from Util

Util::ASGN_NODES, Util::BASIC_LITERALS, Util::EQUALS_ASGN_NODES, Util::LITERALS, 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 included from AutocorrectUnlessChangingAST

#autocorrect

Methods inherited from Cop

#add_offense, all, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, cop_type, #correct, #debug?, #details, #display_cop_names?, #display_style_guide?, #excluded_file?, #extra_details?, inherited, #initialize, #join_force?, lint?, match?, #message, non_rails, qualified_cop_name, rails?, #reference_url, #relevant_file?, #style_guide_url

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search

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

Methods included from PathUtil

hidden?, 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/lambda.rb', line 18

def on_block(node)
  # We're looking for
  # (block
  #   (send nil :lambda)
  #   ...)
  block_method, args, = *node

  return unless block_method == TARGET
  selector = block_method.loc.selector.source
  length = lambda_length(node)

  if selector != '->' && length == 1
    add_offense_for_single_line(node, block_method.loc.expression, args)
  elsif selector == '->' && length > 1
    add_offense(node, block_method.loc.expression, MULTI_MSG)
  end
end