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'],
  '$@' => ['$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 inherited from Cop

Cop::OPERATOR_METHODS

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offences, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offence, all, #autocorrect?, #convention, #cop_config, cop_name, #cop_name, cop_type, #debug?, #ignore_node, inherited, #initialize, lint?, non_rails, rails?, style?, #support_autocorrect?, #warning

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
    MSG_BOTH.format(english_msg, regular_msg, global_var)
  elsif regular.length > 0
    MSG_REGULAR.format(regular_msg, global_var)
  elsif english.length > 0
    MSG_ENGLISH.format(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

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