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Class: RuboCop::Cop::Lint::NestedMethodDefinition

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::RuboCop::Cop::Base, ::RuboCop::ExcludeLimit, NodePattern::Macros, RuboCop::AST::Sexp
Instance Chain:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/lint/nested_method_definition.rb

Overview

Checks for nested method definitions.

Examples:

# bad

# `bar` definition actually produces methods in the same scope
# as the outer `foo` method. Furthermore, the `bar` method
# will be redefined every time `foo` is invoked.
def foo
  def bar
  end
end
# good

def foo
  bar = -> { puts 'hello' }
  bar.call
end
# good

# `class_eval`, `instance_eval`, `module_eval`, `class_exec`, `instance_exec`, and
# `module_exec` blocks are allowed by default.

def foo
  self.class.class_eval do
    def bar
    end
  end
end

def foo
  self.class.module_exec do
    def bar
    end
  end
end
# good

def foo
  class << self
    def bar
    end
  end
end

AllowedMethods: [] (default)

# bad
def do_something
  has_many :articles do
    def find_or_create_by_name(name)
    end
  end
end

AllowedMethods: ['has_many']

# bad
def do_something
  has_many :articles do
    def find_or_create_by_name(name)
    end
  end
end

AllowedPatterns: [] (default)

# bad
def foo(obj)
  obj.do_baz do
    def bar
    end
  end
end

AllowedPatterns: ['baz']

# good
def foo(obj)
  obj.do_baz do
    def bar
    end
  end
end

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

Class Attribute Summary

::RuboCop::Cop::Base - Inherited

.gem_requirements, .lint?,
.support_autocorrect?

Returns if class supports autocorrect.

.support_multiple_source?

Override if your cop should be called repeatedly for multiple investigations Between calls to on_new_investigation and on_investigation_end, the result of processed_source will remain constant.

.builtin?

Class Method Summary

::RuboCop::Cop::Base - Inherited

.autocorrect_incompatible_with

List of cops that should not try to autocorrect at the same time as this cop.

.badge

Naming.

.callbacks_needed, .cop_name, .department,
.documentation_url

Cops (other than builtin) are encouraged to implement this.

.exclude_from_registry

Call for abstract Cop classes.

.inherited,
.joining_forces

Override and return the Force class(es) you need to join.

.match?

Returns true if the cop name or the cop namespace matches any of the given names.

.new,
.requires_gem

Register a version requirement for the given gem name.

.restrict_on_send

::RuboCop::ExcludeLimit - Extended

exclude_limit

Sets up a configuration option to have an exclude limit tracked.

transform

Instance Attribute Summary

Instance Method Summary

::RuboCop::Cop::AllowedPattern - Included

::RuboCop::Cop::AllowedMethods - Included

::RuboCop::Cop::Base - Inherited

#add_global_offense

Adds an offense that has no particular location.

#add_offense

Adds an offense on the specified range (or node with an expression) Unless that offense is disabled for this range, a corrector will be yielded to provide the cop the opportunity to autocorrect the offense.

#begin_investigation

Called before any investigation.

#callbacks_needed,
#cop_config

Configuration Helpers.

#cop_name, #excluded_file?,
#external_dependency_checksum

This method should be overridden when a cop’s behavior depends on state that lives outside of these locations:

#inspect,
#message

Gets called if no message is specified when calling add_offense or add_global_offense Cops are discouraged to override this; instead pass your message directly.

#name

Alias for Base#cop_name.

#offenses,
#on_investigation_end

Called after all on_…​

#on_new_investigation

Called before all on_…​

#on_other_file

Called instead of all on_…​

#parse

There should be very limited reasons for a Cop to do it’s own parsing.

#parser_engine,
#ready

Called between investigations.

#relevant_file?, #target_rails_version, #target_ruby_version, #annotate, #apply_correction, #attempt_correction,
#callback_argument

Reserved for Cop::Cop.

#complete_investigation

Called to complete an investigation.

#correct, #current_corrector,
#current_offense_locations

Reserved for Commissioner:

#current_offenses, #currently_disabled_lines, #custom_severity, #default_severity, #disable_uncorrectable, #enabled_line?, #file_name_matches_any?, #find_message, #find_severity, #range_for_original, #range_from_node_or_range, #reset_investigation, #use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

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

Instance Method Details

#allowed_method_name?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/nested_method_definition.rb', line 126

def allowed_method_name?(node)
  name = node.method_name

  allowed_method?(name) || matches_allowed_pattern?(name)
end

#eval_call?(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/nested_method_definition.rb', line 133

def_node_matcher :eval_call?, <<~PATTERN
  ({block numblock} (send _ {:instance_eval :class_eval :module_eval} ...) ...)
PATTERN

#exec_call?(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/nested_method_definition.rb', line 138

def_node_matcher :exec_call?, <<~PATTERN
  ({block numblock} (send _ {:instance_exec :class_exec :module_exec} ...) ...)
PATTERN

#on_def(node) Also known as: #on_defs

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/nested_method_definition.rb', line 103

def on_def(node)
  subject, = *node
  return if node.defs_type? && subject.lvar_type?

  def_ancestor = node.each_ancestor(:def, :defs).first
  return unless def_ancestor

  within_scoping_def =
    node.each_ancestor(:block, :numblock, :sclass).any? do |ancestor|
      scoping_method_call?(ancestor)
    end

  add_offense(node) if def_ancestor && !within_scoping_def
end

#on_defs(node)

Alias for #on_def.

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/nested_method_definition.rb', line 117

alias on_defs on_def

#scoping_method_call?(child) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/nested_method_definition.rb', line 121

def scoping_method_call?(child)
  child.sclass_type? || eval_call?(child) || exec_call?(child) ||
    child.class_constructor? || allowed_method_name?(child)
end