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

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

Overview

This cop (by default) checks for uses of the lambda literal syntax for single line lambdas, and the method call syntax for multiline lambdas. It is configurable to enforce one of the styles for both single line and multiline lambdas as well.

Examples:


# EnforcedStyle: line_count_dependent (default)

# bad
f = lambda { |x| x }
f = ->(x) do
      x
    end

# good
f = ->(x) { x }
f = lambda do |x|
      x
    end

# EnforcedStyle: lambda

# bad
f = ->(x) { x }
f = ->(x) do
      x
    end

# good
f = lambda { |x| x }
f = lambda do |x|
      x
    end

# EnforcedStyle: literal

# bad
f = lambda { |x| x }
f = lambda do |x|
      x
    end

# good
f = ->(x) { x }
f = ->(x) do
      x
    end

Constant Summary collapse

LITERAL_MESSAGE = 
'Use the `-> { ... }` lambda literal syntax for ' \
'%s lambdas.'.freeze
METHOD_MESSAGE = 
'Use the `lambda` method for %s lambdas.'.freeze
OFFENDING_SELECTORS = 
{
  style: {
    lambda: { single_line: '->', multiline: '->' },
    literal: { single_line: 'lambda', multiline: 'lambda' },
    line_count_dependent: { single_line: 'lambda', multiline: '->' }
  }
}.freeze
TARGET = 
s(:send, nil, :lambda)

Constants included from Util

Util::ASGN_NODES, Util::BYTE_ORDER_MARK, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, 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 ConfigurableEnforcedStyle

#alternative_style, #ambiguous_style_detected, #correct_style_detected, #detected_style, #detected_style=, #no_acceptable_style!, #no_acceptable_style?, #opposite_style_detected, #parameter_name, #style, #style_detected, #supported_styles, #unexpected_style_detected

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?, #duplicate_location?, #excluded_file?, #extra_details?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #messages, non_rails, #parse, qualified_cop_name, #reference_url, #relevant_file?, #style_guide_url, #target_ruby_version

Methods included from 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?, block_length, comment_line?, directions, double_quotes_acceptable?, double_quotes_required?, effective_column, ends_its_line?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_distance, line_range, move_pos, needs_escaping?, numeric_range_size, on_node, operator?, parentheses?, parenthesized_call?, preceed?, range_between, range_with_surrounding_comma, range_with_surrounding_space, same_line?, source_range, strip_quotes, stripped_source_upto, to_string_literal, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, 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 76

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

  return unless block_method == TARGET

  check(node)
end