class RuboCop::Cop::Layout::RedundantLineBreak

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

@example 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('-')

@example InspectBlocks: false (default)

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

@example InspectBlocks: true

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

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

Constants

MSG

Public Instance Methods

on_lvasgn(node) click to toggle source

Calls superclass method RuboCop::Cop::CheckAssignment#on_lvasgn

# 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) click to toggle source

# 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

Private Instance Methods

check_assignment(node, _rhs) click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 72
def check_assignment(node, _rhs)
  return unless offense?(node)

  register_offense(node)
end

comment_within?(node) click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 120
def comment_within?(node)
  processed_source.comments.map(&:loc).map(&:line).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) click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 90
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) click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 114
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) click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 68
def end_with_percent_blank_string?(processed_source)
  processed_source.buffer.source.end_with?("%\n\n")
end

max_line_length() click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 140
def max_line_length
  config.for_cop('Layout/LineLength')['Max']
end

offense?(node) click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 85
def offense?(node)
  node.multiline? && !too_long?(node) && suitable_as_single_line?(node) &&
    !configured_to_not_be_inspected?(node)
end

other_cop_takes_precedence?(node) click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 97
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) click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 78
def register_offense(node)
  add_offense(node) do |corrector|
    corrector.replace(node, to_single_line(node.source).strip)
  end
  ignore_node(node)
end

single_line_block_chain_enabled?() click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 103
def single_line_block_chain_enabled?
  @config.for_cop('Layout/SingleLineBlockChain')['Enabled']
end

suitable_as_single_line?(node) click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 107
def suitable_as_single_line?(node)
  !comment_within?(node) &&
    node.each_descendant(:if, :case, :kwbegin, :def).none? &&
    node.each_descendant(:dstr, :str).none? { |n| n.heredoc? || n.value.include?("\n") } &&
    node.each_descendant(:begin).none? { |b| !b.single_line? }
end

to_single_line(source) click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 131
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
    .gsub(/\s*\\?\n\s*/, ' ')       # Any other line break, with or without backslash
end

too_long?(node) click to toggle source

# File lib/rubocop/cop/layout/redundant_line_break.rb, line 126
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