/
number_conversion.rb
81 lines (71 loc) · 2.2 KB
/
number_conversion.rb
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# frozen_string_literal: true
module RuboCop
module Cop
module Lint
# This cop warns the usage of unsafe number conversions. Unsafe
# number conversion can cause unexpected error if auto type conversion
# fails. Cop prefer parsing with number class instead.
#
# @example
#
# # bad
#
# '10'.to_i
# '10.2'.to_f
# '10'.to_c
#
# # good
#
# Integer('10', 10)
# Float('10.2')
# Complex('10')
class NumberConversion < Cop
CONVERSION_METHOD_CLASS_MAPPING = {
to_i: "#{Integer.name}(%<number_object>s, 10)",
to_f: "#{Float.name}(%<number_object>s)",
to_c: "#{Complex.name}(%<number_object>s)"
}.freeze
MSG = 'Replace unsafe number conversion with number '\
'class parsing, instead of using '\
'%<number_object>s.%<to_method>s, use stricter '\
'%<corrected_method>s.'
def_node_matcher :to_method, <<~PATTERN
(send $_ ${:to_i :to_f :to_c})
PATTERN
def_node_matcher :datetime?, <<~PATTERN
(send (const {nil? (cbase)} {:Time :DateTime}) ...)
PATTERN
def on_send(node)
to_method(node) do |receiver, to_method|
next if receiver.nil? || date_time_object?(receiver)
message = format(
MSG,
number_object: receiver.source,
to_method: to_method,
corrected_method: correct_method(node, receiver)
)
add_offense(node, message: message)
end
end
def autocorrect(node)
lambda do |corrector|
corrector.replace(node,
correct_method(node, node.receiver))
end
end
private
def date_time_object?(node)
child = node
while child&.send_type?
return true if datetime? child
child = child.children[0]
end
end
def correct_method(node, receiver)
format(CONVERSION_METHOD_CLASS_MAPPING[node.method_name],
number_object: receiver.source)
end
end
end
end
end