lib/rubocop/cop/style/multiline_when_then.rb
# frozen_string_literal: true
module RuboCop
module Cop
module Style
# Checks uses of the `then` keyword
# in multi-line when statements.
#
# @example
# # bad
# case foo
# when bar then
# end
#
# # good
# case foo
# when bar
# end
#
# # good
# case foo
# when bar then do_something
# end
#
# # good
# case foo
# when bar then do_something(arg1,
# arg2)
# end
#
class MultilineWhenThen < Base
include RangeHelp
extend AutoCorrector
MSG = 'Do not use `then` for multiline `when` statement.'
def on_when(node)
return if !node.then? || require_then?(node)
range = node.loc.begin
add_offense(range) do |corrector|
corrector.remove(range_with_surrounding_space(range, side: :left, newlines: false))
end
end
private
# Requires `then` for write `when` and its body on the same line.
def require_then?(when_node)
unless when_node.conditions.first.first_line == when_node.conditions.last.last_line
return true
end
return false unless when_node.body
same_line?(when_node, when_node.body)
end
def accept_node_type?(node)
node&.array_type? || node&.hash_type?
end
end
end
end
end