Class: Rubocop::Cop::Style::SelfAssignment

Inherits:
Cop
  • Object
show all
Includes:
AST::Sexp
Defined in:
lib/rubocop/cop/style/self_assignment.rb

Overview

This cop enforces the use the shorthand for self-assignment.

Examples:


# bad
x = x + 1

# good
x += 1

Constant Summary collapse

OPS = 
[:+, :-, :*, :**, :/, :|, :&]

Constants included from Util

Util::ASGN_NODES, Util::EQUALS_ASGN_NODES, Util::OPERATOR_METHODS, Util::PROC_NEW_NODE, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, #autocorrect?, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, cop_type, #debug?, #display_cop_names?, #exclude_file?, #include_file?, inherited, #initialize, lint?, #message, non_rails, rails?, #relevant_file?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

block_length, command?, comment_line?, const_name, first_part_of_call_chain, lambda?, lambda_or_proc?, line_range, on_node, operator?, parentheses?, proc?, range_with_surrounding_space, source_range, strip_quotes

Methods included from PathUtil

match_path?, relative_path

Constructor Details

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

Instance Method Details

#check(node, var_type) ⇒ Object 



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# File 'lib/rubocop/cop/style/self_assignment.rb', line 32

def check(node, var_type)
  var_name, rhs = *node

  return unless rhs

  if rhs.type == :send
    check_send_node(node, rhs, var_name, var_type)
  elsif [:and, :or].include?(rhs.type)
    check_boolean_node(node, rhs, var_name, var_type)
  end
end

#check_boolean_node(node, rhs, var_name, var_type) ⇒ Object 



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# File 'lib/rubocop/cop/style/self_assignment.rb', line 58

def check_boolean_node(node, rhs, var_name, var_type)
  first_operand, _second_operand = *rhs

  target_node = s(var_type, var_name)

  if first_operand == target_node
    operator = rhs.loc.operator.source
    add_offense(node,
                :expression,
                "Use self-assignment shorthand `#{operator}=`.")
  end
end

#check_send_node(node, rhs, var_name, var_type) ⇒ Object 



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# File 'lib/rubocop/cop/style/self_assignment.rb', line 44

def check_send_node(node, rhs, var_name, var_type)
  receiver, method_name, *_args = *rhs

  return unless OPS.include?(method_name)

  target_node = s(var_type, var_name)

  if receiver == target_node
    add_offense(node,
                :expression,
                "Use self-assignment shorthand `#{method_name}=`.")
  end
end

#on_cvasgn(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/self_assignment.rb', line 28

def on_cvasgn(node)
  check(node, :cvar)
end

#on_ivasgn(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/self_assignment.rb', line 24

def on_ivasgn(node)
  check(node, :ivar)
end

#on_lvasgn(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/self_assignment.rb', line 20

def on_lvasgn(node)
  check(node, :lvar)
end