Class: RuboCop::Cop::Style::GlobalVars

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

Overview

This cops looks for uses of global variables. It does not report offenses for built-in global variables. Built-in global variables are allowed by default. Additionally users can allow additional variables via the AllowedVariables option.

Note that backreferences like $1, $2, etc are not global variables.

Examples:

# bad
$foo = 2
bar = $foo + 5

# good
FOO = 2
foo = 2
$stdin.read

Constant Summary collapse

MSG = 
'Do not introduce global variables.'.freeze
BUILT_IN_VARS =

built-in global variables and their English aliases www.zenspider.com/Languages/Ruby/QuickRef.html

%w[
  $: $LOAD_PATH
  $" $LOADED_FEATURES
  $0 $PROGRAM_NAME
  $! $ERROR_INFO
  $@ $ERROR_POSITION
  $; $FS $FIELD_SEPARATOR
  $, $OFS $OUTPUT_FIELD_SEPARATOR
  $/ $RS $INPUT_RECORD_SEPARATOR
  $\\ $ORS $OUTPUT_RECORD_SEPARATOR
  $. $NR $INPUT_LINE_NUMBER
  $_ $LAST_READ_LINE
  $> $DEFAULT_OUTPUT
  $< $DEFAULT_INPUT
  $$ $PID $PROCESS_ID
  $? $CHILD_STATUS
  $~ $LAST_MATCH_INFO
  $= $IGNORECASE
  $* $ARGV
  $& $MATCH
  $` $PREMATCH
  $' $POSTMATCH
  $+ $LAST_PAREN_MATCH
  $stdin $stdout $stderr
  $DEBUG $FILENAME $VERBOSE $SAFE
  $-0 $-a $-d $-F $-i $-I $-l $-p $-v $-w
  $CLASSPATH $JRUBY_VERSION $JRUBY_REVISION $ENV_JAVA
].map(&:to_sym)

Constants included from Util

Util::ASGN_NODES, Util::CONDITIONAL_NODES, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::LOGICAL_OPERATOR_NODES, Util::MODIFIER_NODES, Util::OPERATOR_METHODS, 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_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, #correct, department, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from AST::Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, operator?, parentheses?, same_line?, to_string_literal, to_supported_styles, tokens

Methods included from PathUtil

absolute?, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

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

Instance Method Details

#allowed_var?(global_var) ⇒ Boolean

Returns:

  • (Boolean) 


60
61
62
 
# File 'lib/rubocop/cop/style/global_vars.rb', line 60

def allowed_var?(global_var)
  BUILT_IN_VARS.include?(global_var) || user_vars.include?(global_var)
end

#check(node) ⇒ Object 



72
73
74
75
76
 
# File 'lib/rubocop/cop/style/global_vars.rb', line 72

def check(node)
  global_var, = *node

  add_offense(node, location: :name) unless allowed_var?(global_var)
end

#on_gvar(node) ⇒ Object 



64
65
66
 
# File 'lib/rubocop/cop/style/global_vars.rb', line 64

def on_gvar(node)
  check(node)
end

#on_gvasgn(node) ⇒ Object 



68
69
70
 
# File 'lib/rubocop/cop/style/global_vars.rb', line 68

def on_gvasgn(node)
  check(node)
end

#user_vars ⇒ Object 



56
57
58
 
# File 'lib/rubocop/cop/style/global_vars.rb', line 56

def user_vars
  cop_config['AllowedVariables'].map(&:to_sym)
end