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Class: RuboCop::Cop::Layout::RedundantLineBreak

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::RuboCop::Cop::AutoCorrector, ::RuboCop::Cop::Base, ::RuboCop::ExcludeLimit, NodePattern::Macros, RuboCop::AST::Sexp
Instance Chain:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/layout/redundant_line_break.rb

Overview

Checks whether certain expressions, e.g. method calls, that could fit completely on a single line, are broken up into multiple lines unnecessarily.

Examples:

any configuration

# bad
foo(
  a,
  b
)

puts 'string that fits on ' \
     'a single line'

things
  .select { |thing| thing.cond? }
  .join('-')

# good
foo(a, b)

puts 'string that fits on a single line'

things.select { |thing| thing.cond? }.join('-')

InspectBlocks: false (default)

# good
foo(a) do |x|
  puts x
end

InspectBlocks: true

# bad
foo(a) do |x|
  puts x
end

# good
foo(a) { |x| puts x }

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

::RuboCop::Cop::Base - Inherited

.gem_requirements, .lint?,
.support_autocorrect?

Returns if class supports autocorrect.

.support_multiple_source?

Override if your cop should be called repeatedly for multiple investigations Between calls to on_new_investigation and on_investigation_end, the result of processed_source will remain constant.

Class Method Summary

::RuboCop::Cop::Base - Inherited

.autocorrect_incompatible_with

List of cops that should not try to autocorrect at the same time as this cop.

.badge

Naming.

.callbacks_needed, .cop_name, .department,
.documentation_url

Returns an url to view this cops documentation online.

.exclude_from_registry

Call for abstract Cop classes.

.inherited,
.joining_forces

Override and return the Force class(es) you need to join.

.match?

Returns true if the cop name or the cop namespace matches any of the given names.

.new,
.requires_gem

Register a version requirement for the given gem name.

.restrict_on_send

::RuboCop::ExcludeLimit - Extended

exclude_limit

Sets up a configuration option to have an exclude limit tracked.

transform

Instance Attribute Summary

Instance Method Summary

::RuboCop::Cop::CheckAssignment - Included

::RuboCop::Cop::Base - Inherited

#add_global_offense

Adds an offense that has no particular location.

#add_offense

Adds an offense on the specified range (or node with an expression) Unless that offense is disabled for this range, a corrector will be yielded to provide the cop the opportunity to autocorrect the offense.

#begin_investigation

Called before any investigation.

#callbacks_needed,
#cop_config

Configuration Helpers.

#cop_name, #excluded_file?,
#external_dependency_checksum

This method should be overridden when a cop’s behavior depends on state that lives outside of these locations:

#inspect
#message

Gets called if no message is specified when calling add_offense or add_global_offense Cops are discouraged to override this; instead pass your message directly.

#name

Alias for Base#cop_name.

#offenses,
#on_investigation_end

Called after all on_…​

#on_new_investigation

Called before all on_…​

#on_other_file

Called instead of all on_…​

#parse

There should be very limited reasons for a Cop to do it’s own parsing.

#parser_engine,
#ready

Called between investigations.

#relevant_file?, #target_rails_version, #target_ruby_version, #annotate, #apply_correction, #attempt_correction,
#callback_argument

Reserved for Cop::Cop.

#complete_investigation

Called to complete an investigation.

#correct, #current_corrector,
#current_offense_locations

Reserved for Commissioner:

#current_offenses, #currently_disabled_lines, #custom_severity, #default_severity, #disable_uncorrectable, #enabled_line?, #file_name_matches_any?, #find_message, #find_severity, #range_for_original, #range_from_node_or_range,
#reset_investigation

Actually private methods.

#use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

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

Instance Attribute Details

#single_line_block_chain_enabled?Boolean (readonly, private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 116

def single_line_block_chain_enabled?
  @config.for_cop('Layout/SingleLineBlockChain')['Enabled']
end

Instance Method Details

#check_assignment(node, _rhs) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 73

def check_assignment(node, _rhs)
  return unless offense?(node)

  register_offense(node)
end

#comment_within?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 133

def comment_within?(node)
  comment_line_numbers = processed_source.comments.map { |comment| comment.loc.line }

  comment_line_numbers.any? do |comment_line_number|
    comment_line_number >= node.first_line && comment_line_number <= node.last_line
  end
end

#configured_to_not_be_inspected?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 103

def configured_to_not_be_inspected?(node)
  return true if other_cop_takes_precedence?(node)

  !cop_config['InspectBlocks'] && (node.block_type? ||
                                   any_descendant?(node, :block, &:multiline?))
end

#convertible_block?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 127

def convertible_block?(node)
  parent = node.parent
  parent&.block_type? && node == parent.send_node &&
    (node.parenthesized? || !node.arguments?)
end

#end_with_percent_blank_string?(processed_source) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 69

def end_with_percent_blank_string?(processed_source)
  processed_source.buffer.source.end_with?("%\n\n")
end

#index_access_call_chained?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 97

def index_access_call_chained?(node)
  return false unless node.send_type? && node.method?(:[])

  node.children.first.send_type? && node.children.first.method?(:[])
end

#max_line_length (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 155

def max_line_length
  config.for_cop('Layout/LineLength')['Max']
end

#offense?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 86

def offense?(node)
  return false if !node.multiline? || too_long?(node) || !suitable_as_single_line?(node)
  return require_backslash?(node) if node.and_type? || node.or_type?

  !index_access_call_chained?(node) && !configured_to_not_be_inspected?(node)
end

#on_csend(node)

Alias for #on_send.

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 65

alias on_csend on_send

#on_lvasgn(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 51

def on_lvasgn(node)
  super unless end_with_percent_blank_string?(processed_source)
end

#on_send(node) Also known as: #on_csend

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 55

def on_send(node)
  # Include "the whole expression".
  node = node.parent while node.parent&.send_type? ||
                           convertible_block?(node) ||
                           node.parent.is_a?(RuboCop::AST::BinaryOperatorNode)

  return unless offense?(node) && !part_of_ignored_node?(node)

  register_offense(node)
end

#other_cop_takes_precedence?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 110

def other_cop_takes_precedence?(node)
  single_line_block_chain_enabled? && any_descendant?(node, :block) do |block_node|
    block_node.parent.send_type? && block_node.parent.loc.dot && !block_node.multiline?
  end
end

#register_offense(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 79

def register_offense(node)
  add_offense(node) do |corrector|
    corrector.replace(node, to_single_line(node.source).strip)
  end
  ignore_node(node)
end

#require_backslash?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 93

def require_backslash?(node)
  processed_source.lines[node.loc.operator.line - 1].end_with?('\\')
end

#suitable_as_single_line?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 120

def suitable_as_single_line?(node)
  !comment_within?(node) &&
    node.each_descendant(:if, :case, :kwbegin, :def, :defs).none? &&
    node.each_descendant(:dstr, :str).none? { |n| n.heredoc? || n.value.include?("\n") } &&
    node.each_descendant(:begin, :sym).none? { |b| !b.single_line? }
end

#to_single_line(source) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 146

def to_single_line(source)
  source
    .gsub(/" *\\\n\s*'/, %q(" + ')) # Double quote, backslash, and then single quote
    .gsub(/' *\\\n\s*"/, %q(' + ")) # Single quote, backslash, and then double quote
    .gsub(/(["']) *\\\n\s*\1/, '')  # Double or single quote, backslash, then same quote
    .gsub(/\n\s*(?=(&)?\.\w)/, '')  # Extra space within method chaining which includes `&.`
    .gsub(/\s*\\?\n\s*/, ' ')       # Any other line break, with or without backslash
end

#too_long?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/redundant_line_break.rb', line 141

def too_long?(node)
  lines = processed_source.lines[(node.first_line - 1)...node.last_line]
  to_single_line(lines.join("\n")).length > max_line_length
end