Class: RuboCop::Cop::MagicNumbers::NoAssignment

Inherits:
Base
  • Object
show all
Defined in:
lib/rubocop/cop/magic_numbers/no_assignment.rb

Overview

Adds violations for magic numbers, aka assignments to variables with bare numbers, configurable by literal type. Can detect local, instance, global, and setter assignment, and works on multiple assignment.

bad: hours = 24

good: HOURS_IN_ONE_DAY = 24

Constant Summary collapse

MAGIC_NUMBER_ARGUMENT_TO_SETTER_PATTERN = 
<<-PATTERN
  (send
    ({send self} ...)
    $_
    $(%<illegal_scalar_pattern>s _)
  )
PATTERN
MAGIC_NUMBER_MULTI_ASSIGN_PATTERN = 
<<-PATTERN
  (masgn
    (mlhs ({lvasgn ivasgn send} ...)+)
    {
      $(%<illegal_scalar_pattern>s _)
      $(array <(%<illegal_scalar_pattern>s _) ...>)
    }
  )
PATTERN
LOCAL_VARIABLE_ASSIGN_MSG = 
'Do not use magic number local variables'
INSTANCE_VARIABLE_ASSIGN_MSG = 
'Do not use magic number instance variables'
MULTIPLE_ASSIGN_MSG = 
'Do not use magic numbers in multiple assignments'
PROPERTY_MSG = 
'Do not use magic numbers to set properties'
DEFAULT_CONFIG = 
{
  'AllowedAssignments' => %w[class_variables global_variables],
  'PermittedValues' => []
}.freeze

Constants inherited from Base

Base::CONFIG_ALL, Base::CONFIG_FLOAT, Base::CONFIG_INTEGER, Base::CONFIG_NAME_FORBIDDEN_NUMERICS, Base::ILLEGAL_SCALAR_TYPES

Instance Method Summary collapse

Instance Method Details

#cop_config ⇒ Object 



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# File 'lib/rubocop/cop/magic_numbers/no_assignment.rb', line 42

def cop_config
  DEFAULT_CONFIG.merge(super)
end

#on_instance_variable_assignment(node) ⇒ Object Also known as: on_ivasgn 



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# File 'lib/rubocop/cop/magic_numbers/no_assignment.rb', line 54

def on_instance_variable_assignment(node)
  return unless illegal_scalar_value?(node)
  return unless node_within_method?(node)

  add_offense(node, message: INSTANCE_VARIABLE_ASSIGN_MSG)
end

#on_local_variable_assignment(node) ⇒ Object Also known as: on_lvasgn 



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# File 'lib/rubocop/cop/magic_numbers/no_assignment.rb', line 46

def on_local_variable_assignment(node)
  return unless illegal_scalar_value?(node)
  return unless node_within_method?(node)

  add_offense(node, message: LOCAL_VARIABLE_ASSIGN_MSG)
end

#on_message_send(node) ⇒ Object Also known as: on_send 



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# File 'lib/rubocop/cop/magic_numbers/no_assignment.rb', line 62

def on_message_send(node)
  return unless illegal_scalar_argument_to_setter?(node)
  return unless node_within_method?(node)

  add_offense(node, message: PROPERTY_MSG)
end

#on_multiple_assign(node) ⇒ Object Also known as: on_masgn 



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# File 'lib/rubocop/cop/magic_numbers/no_assignment.rb', line 70

def on_multiple_assign(node)
  # multiassignment nodes aren't AsgnNode typed, so we need to have a
  # special approach to deconstruct them and assess if they contain magic
  # numbers amongst their assignments
  return false unless illegal_multi_assign_right_hand_side?(node)

  add_offense(node, message: MULTIPLE_ASSIGN_MSG)
end