Class: RuboCop::Cop::Rails::Delegate

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/rails/delegate.rb

Overview

This cop looks for delegations that could have been created automatically with the `delegate` method.

Safe navigation `&.` is ignored because Rails' `allow_nil` option checks not just for nil but also delegates if nil responds to the delegated method.

The `EnforceForPrefixed` option (defaulted to `true`) means that using the target object as a prefix of the method name without using the `delegate` method will be a violation. When set to `false`, this case is legal.

Examples:

# bad
def bar
  foo.bar
end

# good
delegate :bar, to: :foo

# good
def bar
  foo&.bar
end

# good
private
def bar
  foo.bar
end

EnforceForPrefixed: true (default)

# bad
def foo_bar
  foo.bar
end

# good
delegate :bar, to: :foo, prefix: true

EnforceForPrefixed: false

# good
def foo_bar
  foo.bar
end

# good
delegate :bar, to: :foo, prefix: true

Constant Summary collapse

MSG =
'Use `delegate` to define delegations.'.freeze

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, autocorrect_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, #correct, department, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AST::Sexp

#s

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, parentheses?, same_line?, to_string_literal, to_supported_styles, tokens

Methods included from PathUtil

absolute?, hidden_dir?, hidden_file_in_not_hidden_dir?, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

This class inherits a constructor from RuboCop::Cop::Cop

Instance Method Details

#autocorrect(node) ⇒ Object



70
71
72
73
74
75
76
77
78
79
80
81
82
# File 'lib/rubocop/cop/rails/delegate.rb', line 70

def autocorrect(node)
  method_name, _args, body = *node
  delegation = ["delegate :#{body.method_name}",
                "to: :#{body.receiver.method_name}"]

  if method_name == prefixed_method_name(body)
    delegation << ['prefix: true']
  end

  lambda do |corrector|
    corrector.replace(node.source_range, delegation.join(', '))
  end
end

#on_def(node) ⇒ Object



63
64
65
66
67
68
# File 'lib/rubocop/cop/rails/delegate.rb', line 63

def on_def(node)
  return unless trivial_delegate?(node)
  return if private_or_protected_delegation(node)

  add_offense(node, location: :keyword)
end