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

Inherits:

Base

• Object
• Base
• RuboCop::Cop::Style::Lambda

Extended by:

AutoCorrector

Includes:

ConfigurableEnforcedStyle

Defined in:

lib/rubocop/cop/style/lambda.rb

Overview

(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

LITERAL_MESSAGE =

'Use the `-> { ... }` lambda literal syntax for %<modifier>s lambdas.'

METHOD_MESSAGE =

'Use the `lambda` method for %<modifier>s lambdas.'

OFFENDING_SELECTORS =

{
  style: {
    lambda: { single_line: '->', multiline: '->' },
    literal: { single_line: 'lambda', multiline: 'lambda' },
    line_count_dependent: { single_line: 'lambda', multiline: '->' }
  }
}.freeze

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary

• #on_block(node) ⇒ Object (also: #on_numblock, #on_itblock)

Methods included from AutoCorrector

support_autocorrect?

Methods included from ConfigurableEnforcedStyle

#alternative_style, #alternative_styles, #ambiguous_style_detected, #correct_style_detected, #detected_style, #detected_style=, #no_acceptable_style!, #no_acceptable_style?, #opposite_style_detected, #style, #style_configured?, #style_detected, #style_parameter_name, #supported_styles, #unexpected_style_detected

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, autocorrect_incompatible_with, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #cop_config, cop_name, #cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, support_autocorrect?, support_multiple_source?, #target_gem_version, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

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

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

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

Instance Method Details

#on_block(node) ⇒ Object Also known as: on_numblock, on_itblock

# File 'lib/rubocop/cop/style/lambda.rb', line 64

def on_block(node)
  return unless node.lambda?

  selector = node.send_node.source

  return unless offending_selector?(node, selector)

  add_offense(node.send_node, message: message(node, selector)) do |corrector|
    if node.send_node.lambda_literal?
      LambdaLiteralToMethodCorrector.new(node).call(corrector)
    else
      autocorrect_method_to_literal(corrector, node)
    end
  end
end