Sha256: 2d54e043c0754b177143507391283654b56646096a4993ac070121dc674ac349
Contents?: true
Size: 1.96 KB
Versions: 17
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Stored size: 1.96 KB
Contents
# frozen_string_literal: true
module RuboCop
module Cop
module Style
# This cop checks for the presence of `method_missing` without also
# defining `respond_to_missing?` and falling back on `super`.
#
# @example
# #bad
# def method_missing(...)
# ...
# end
#
# #good
# def respond_to_missing?(...)
# ...
# end
#
# def method_missing(...)
# ...
# super
# end
class MethodMissing < Cop
include OnMethodDef
MSG = 'When using `method_missing`, %s.'.freeze
def on_method_def(node, method_name, _args, _body)
return unless method_name == :method_missing
check(node)
end
private
def check(node)
return if calls_super?(node) && implements_respond_to_missing?(node)
add_offense(node, :expression)
end
def message(node)
instructions = []
unless implements_respond_to_missing?(node)
instructions << 'define `respond_to_missing?`'.freeze
end
unless calls_super?(node)
instructions << 'fall back on `super`'.freeze
end
format(MSG, instructions.join(' and '))
end
def calls_super?(node)
node.descendants.any?(&:zsuper_type?)
end
def implements_respond_to_missing?(node)
node.parent.each_child_node(node.type).any? do |sibling|
if node.def_type?
respond_to_missing_def?(sibling)
elsif node.defs_type?
respond_to_missing_defs?(sibling)
end
end
end
def_node_matcher :respond_to_missing_def?, <<-PATTERN
(def :respond_to_missing? (...) ...)
PATTERN
def_node_matcher :respond_to_missing_defs?, <<-PATTERN
(defs (self) :respond_to_missing? (...) ...)
PATTERN
end
end
end
end
Version data entries
17 entries across 17 versions & 2 rubygems