Class: RuboCop::Cop::Style::SpecialGlobalVars

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/style/special_global_vars.rb

Overview

This cop looks for uses of Perl-style global variables.

Constant Summary collapse

MSG_BOTH =
'Prefer `%s` from the English library, or `%s` over `%s`.'
MSG_ENGLISH =
'Prefer `%s` from the English library over `%s`.'
MSG_REGULAR =
'Prefer `%s` over `%s`.'
PREFERRED_VARS =
{
  '$:' => ['$LOAD_PATH'],
  '$"' => ['$LOADED_FEATURES'],
  '$0' => ['$PROGRAM_NAME'],
  '$!' => ['$ERROR_INFO'],
  '[email protected]' => ['$ERROR_POSITION'],
  '$;' => ['$FIELD_SEPARATOR', '$FS'],
  '$,' => ['$OUTPUT_FIELD_SEPARATOR', '$OFS'],
  '$/' => ['$INPUT_RECORD_SEPARATOR', '$RS'],
  '$\\' => ['$OUTPUT_RECORD_SEPARATOR', '$ORS'],
  '$.' => ['$INPUT_LINE_NUMBER', '$NR'],
  '$_' => ['$LAST_READ_LINE'],
  '$>' => ['$DEFAULT_OUTPUT'],
  '$<' => ['$DEFAULT_INPUT'],
  '$$' => ['$PROCESS_ID', '$PID'],
  '$?' => ['$CHILD_STATUS'],
  '$~' => ['$LAST_MATCH_INFO'],
  '$=' => ['$IGNORECASE'],
  '$*' => ['$ARGV', 'ARGV'],
  '$&' => ['$MATCH'],
  '$`' => ['$PREMATCH'],
  '$\'' => ['$POSTMATCH'],
  '$+' => ['$LAST_PAREN_MATCH']
}.symbolize_keys
NON_ENGLISH_VARS =

Anything not in this set is provided by the English library.

Set.new([
  '$LOAD_PATH',
  '$LOADED_FEATURES',
  '$PROGRAM_NAME',
  'ARGV'
])

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, #join_force?, lint?, 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

#autocorrect(node) ⇒ Object


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# File 'lib/rubocop/cop/style/special_global_vars.rb', line 73

def autocorrect(node)
  @corrections << lambda do |corrector|
    global_var, = *node

    corrector.replace(node.loc.expression,
                      PREFERRED_VARS[global_var].first)
  end
end

#message(node) ⇒ Object


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# File 'lib/rubocop/cop/style/special_global_vars.rb', line 51

def message(node)
  global_var, = *node

  regular, english = PREFERRED_VARS[global_var].partition do |var|
    NON_ENGLISH_VARS.include? var
  end

  # For now, we assume that lists are 2 items or less. Easy grammar!
  regular_msg = regular.join('` or `')
  english_msg = english.join('` or `')

  if regular.length > 0 && english.length > 0
    format(MSG_BOTH, english_msg, regular_msg, global_var)
  elsif regular.length > 0
    format(MSG_REGULAR, regular_msg, global_var)
  elsif english.length > 0
    format(MSG_ENGLISH, english_msg, global_var)
  else
    fail 'Bug in SpecialGlobalVars - global var w/o preferred vars!'
  end
end

#on_gvar(node) ⇒ Object


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# File 'lib/rubocop/cop/style/special_global_vars.rb', line 45

def on_gvar(node)
  global_var, = *node

  add_offense(node, :expression) if PREFERRED_VARS[global_var]
end