lib/rubocop/cop/lint/parentheses_as_grouped_expression.rb
# frozen_string_literal: true
module RuboCop
module Cop
module Lint
# Checks for space between the name of a called method and a left
# parenthesis.
#
# @example
#
# # bad
# do_something (foo)
#
# # good
# do_something(foo)
# do_something (2 + 3) * 4
# do_something (foo * bar).baz
class ParenthesesAsGroupedExpression < Base
include RangeHelp
extend AutoCorrector
MSG = '`%<argument>s` interpreted as grouped expression.'
def on_send(node)
return if valid_context?(node)
space_length = spaces_before_left_parenthesis(node)
return unless space_length.positive?
range = space_range(node.first_argument.source_range, space_length)
message = format(MSG, argument: node.first_argument.source)
add_offense(range, message: message) { |corrector| corrector.remove(range) }
end
alias on_csend on_send
private
def valid_context?(node)
unless node.arguments.one? && first_argument_starts_with_left_parenthesis?(node)
return true
end
return true if first_argument_block_type?(node.first_argument)
node.operator_method? || node.setter_method? || chained_calls?(node) ||
valid_first_argument?(node.first_argument)
end
def first_argument_block_type?(first_arg)
first_arg.block_type? || first_arg.numblock_type?
end
def valid_first_argument?(first_arg)
first_arg.operator_keyword? || first_arg.hash_type? || ternary_expression?(first_arg)
end
def first_argument_starts_with_left_parenthesis?(node)
node.first_argument.source.start_with?('(')
end
def chained_calls?(node)
first_argument = node.first_argument
first_argument.call_type? && (node.children.last&.children&.count || 0) > 1
end
def ternary_expression?(node)
node.if_type? && node.ternary?
end
def spaces_before_left_parenthesis(node)
receiver = node.receiver
receiver_length = if receiver
receiver.source.length
else
0
end
without_receiver = node.source[receiver_length..]
# Escape question mark if any.
method_regexp = Regexp.escape(node.method_name)
match = without_receiver.match(/^\s*&?\.?\s*#{method_regexp}(\s+)\(/)
match ? match.captures[0].length : 0
end
def space_range(expr, space_length)
range_between(expr.begin_pos - space_length, expr.begin_pos)
end
end
end
end
end