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

Inherits:
Cop
  • Object
show all
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) {...}`.'
MULTI_MSG =
'Use the `lambda` method for multi-line lambdas.'
TARGET =
s(:send, nil, :lambda)

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/lambda.rb', line 15

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

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

  if selector != '->' && lambda_length == 0
    add_offense(block_method, :expression, SINGLE_MSG)
  elsif selector == '->' && lambda_length > 0
    add_offense(block_method, :expression, MULTI_MSG)
  end
end