Class: RuboCop::Cop::Lint::UnderscorePrefixedVariableName

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/lint/underscore_prefixed_variable_name.rb

Overview

This cop checks for underscore-prefixed variables that are actually used.

Constant Summary collapse

MSG =
'Do not use prefix `_` for a variable that is used.'

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_name_with_namespace, cop_type, #debug?, #display_cop_names?, inherited, #initialize, lint?, #message, non_rails, qualified_cop_name, rails?, #relevant_file?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

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

Methods included from PathUtil

issue_deprecation_warning, match_path?, relative_path

Constructor Details

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

Instance Method Details

#after_leaving_scope(scope, _variable_table) ⇒ Object


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# File 'lib/rubocop/cop/lint/underscore_prefixed_variable_name.rb', line 15

def after_leaving_scope(scope, _variable_table)
  scope.variables.each_value do |variable|
    check_variable(variable)
  end
end

#check_variable(variable) ⇒ Object


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# File 'lib/rubocop/cop/lint/underscore_prefixed_variable_name.rb', line 21

def check_variable(variable)
  return unless variable.should_be_unused?
  return if variable.references.empty?
  return if variable.references.none?(&:explicit?)

  node = variable.declaration_node

  location = if node.type == :match_with_lvasgn
               node.children.first.loc.expression
             else
               node.loc.name
             end

  add_offense(nil, location)
end

#join_force?(force_class) ⇒ Boolean

Returns:

  • (Boolean)

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# File 'lib/rubocop/cop/lint/underscore_prefixed_variable_name.rb', line 11

def join_force?(force_class)
  force_class == VariableForce
end