class RuboCop::Cop::Style::MultilineBlockLayout

This cop checks whether the multiline do end blocks have a newline after the start of the block. Additionally, it checks whether the block arguments, if any, are on the same line as the start of the block.

@example

# bad
blah do |i| foo(i)
  bar(i)
end

# bad
blah do
  |i| foo(i)
  bar(i)
end

# good
blah do |i|
  foo(i)
  bar(i)
end

# bad
blah { |i| foo(i)
  bar(i)
}

# good
blah { |i|
  foo(i)
  bar(i)
}

Constants

ARG_MSG
MSG

Public Instance Methods

add_offense_for_expression(node, expr, msg) click to toggle source
# File lib/rubocop/cop/style/multiline_block_layout.rb, line 66
def add_offense_for_expression(node, expr, msg)
  expression = expr.source_range
  range = Parser::Source::Range.new(expression.source_buffer,
                                    expression.begin_pos,
                                    expression.end_pos)

  add_offense(node, range, msg)
end
autocorrect(node) click to toggle source
# File lib/rubocop/cop/style/multiline_block_layout.rb, line 75
def autocorrect(node)
  lambda do |corrector|
    _method, args, block_body = *node
    unless args.children.empty? || args.loc.last_line == node.loc.line
      autocorrect_arguments(corrector, node, args)
      expr_before_body = args.source_range.end
    end

    return unless block_body

    expr_before_body ||= node.loc.begin
    if expr_before_body.line == block_body.loc.line
      autocorrect_body(corrector, node, block_body)
    end
  end
end
autocorrect_arguments(corrector, node, args) click to toggle source
# File lib/rubocop/cop/style/multiline_block_layout.rb, line 92
def autocorrect_arguments(corrector, node, args)
  end_pos =
    range_with_surrounding_space(args.source_range, :right, false)
    .end_pos
  range = Parser::Source::Range.new(args.source_range.source_buffer,
                                    node.loc.begin.end.begin_pos,
                                    end_pos)
  corrector.replace(range, " |#{block_arg_string(args)}|")
end
autocorrect_body(corrector, node, block_body) click to toggle source
# File lib/rubocop/cop/style/multiline_block_layout.rb, line 102
def autocorrect_body(corrector, node, block_body)
  first_node = if block_body.type == :begin
                 block_body.children.first
               else
                 block_body
               end

  block_start_col = node.source_range.column

  corrector.insert_before(first_node.source_range,
                          "\n  #{' ' * block_start_col}")
end
block_arg_string(args) click to toggle source
# File lib/rubocop/cop/style/multiline_block_layout.rb, line 115
def block_arg_string(args)
  args.children.map do |arg|
    if arg.mlhs_type?
      "(#{block_arg_string(arg)})"
    else
      arg.source
    end
  end.join(', ')
end
on_block(node) click to toggle source
# File lib/rubocop/cop/style/multiline_block_layout.rb, line 44
def on_block(node)
  end_loc = node.loc.end
  do_loc = node.loc.begin # Actually it's either do or {.
  return if do_loc.line == end_loc.line # One-liner, no newline needed.

  # A block node has three children: the block start,
  # the arguments, and the expression. We care if the block start
  # with arguments and the expression start on the same line.
  _block_start, args, last_expression = node.children

  unless args.children.empty?
    if do_loc.line != args.loc.last_line
      add_offense_for_expression(node, args, ARG_MSG)
    end
  end

  return unless last_expression
  expression_loc = last_expression.loc
  return unless do_loc.line == expression_loc.line
  add_offense_for_expression(node, last_expression, MSG)
end