lib/rubocop/cop/style/multiline_method_signature.rb
# frozen_string_literal: true
module RuboCop
module Cop
module Style
# Checks for method signatures that span multiple lines.
#
# @example
#
# # good
#
# def foo(bar, baz)
# end
#
# # bad
#
# def foo(bar,
# baz)
# end
#
class MultilineMethodSignature < Base
include RangeHelp
extend AutoCorrector
MSG = 'Avoid multi-line method signatures.'
def on_def(node)
return unless node.arguments?
return if opening_line(node) == closing_line(node)
return if correction_exceeds_max_line_length?(node)
return unless (begin_of_arguments = node.arguments.loc.begin)
add_offense(node) do |corrector|
autocorrect(corrector, node, begin_of_arguments)
end
end
alias on_defs on_def
private
# rubocop:disable Metrics/AbcSize
def autocorrect(corrector, node, begin_of_arguments)
arguments = node.arguments
joined_arguments = arguments.map(&:source).join(', ')
last_line_source_of_arguments = last_line_source_of_arguments(arguments)
if last_line_source_of_arguments.start_with?(')')
joined_arguments = "#{joined_arguments}#{last_line_source_of_arguments}"
corrector.remove(range_by_whole_lines(arguments.loc.end, include_final_newline: true))
end
arguments_range = arguments_range(node)
# If the method name isn't on the same line as def, move it directly after def
if arguments_range.first_line != opening_line(node)
corrector.remove(node.loc.name)
corrector.insert_after(node.loc.keyword, " #{node.loc.name.source}")
end
corrector.remove(arguments_range)
corrector.insert_after(begin_of_arguments, joined_arguments)
end
# rubocop:enable Metrics/AbcSize
def last_line_source_of_arguments(arguments)
processed_source[arguments.last_line - 1].strip
end
def arguments_range(node)
range = range_between(
node.first_argument.source_range.begin_pos, node.last_argument.source_range.end_pos
)
range_with_surrounding_space(range, side: :left)
end
def opening_line(node)
node.first_line
end
def closing_line(node)
node.arguments.last_line
end
def correction_exceeds_max_line_length?(node)
indentation_width(node) + definition_width(node) > max_line_length
end
def indentation_width(node)
processed_source.line_indentation(node.source_range.line)
end
def definition_width(node)
node.source_range.begin.join(node.arguments.source_range.end).length
end
def max_line_length
config.for_cop('Layout/LineLength')['Max'] || 120
end
end
end
end
end