(PUP-11993) Style/PerlBackrefs

This commit enables the Style/PerlBackrefs cop and fixes 137
autocorrectable offenses.

Author: AriaXLi

.rubocop_todo.yml

@@ -640,10 +640,6 @@ Style/NumericPredicate:
 Style/OptionalBooleanParameter:
   Enabled: false
 
-# This cop supports safe auto-correction (--auto-correct).
-Style/PerlBackrefs:
-  Enabled: false
-
 # This cop supports unsafe auto-correction (--auto-correct-all).
 # Configuration parameters: EnforcedStyle.
 # SupportedStyles: short, verbose

lib/puppet/application/describe.rb

@@ -20,8 +20,8 @@ def wrap(txt, opts)
 
     while work.length > textLen
       if work =~ patt
-        res << $1
-        work.slice!(0, $MATCH.length)
+        res << ::Regexp.last_match(1)
+        work.slice!(0, ::Regexp.last_match(0).length)
       else
         res << work.slice!(0, textLen)
       end
@@ -43,7 +43,7 @@ def scrub(text)
     # If we can match an indentation, then just remove that same level of
     # indent from every line.
     if text =~ /^(\s+)/
-      indent = $1
+      indent = ::Regexp.last_match(1)
       return text.gsub(/^#{indent}/, '')
     else
       return text

lib/puppet/application/resource.rb

@@ -207,7 +207,7 @@ def parse_args(args)
     params = {}
     args.each do |setting|
       if setting =~ /^(\w+)=(.+)$/
-        params[$1] = $2
+        params[::Regexp.last_match(1)] = ::Regexp.last_match(2)
       else
         raise _("Invalid parameter setting %{setting}") % { setting: setting }
       end

lib/puppet/file_serving/configuration/parser.rb

@@ -25,10 +25,10 @@ def parse
         when /^\s*#/; next # skip comments
         when /^\s*$/; next # skip blank lines
         when /\[([-\w]+)\]/
-          mount = newmount($1)
+          mount = newmount(::Regexp.last_match(1))
         when /^\s*(\w+)\s+(.+?)(\s*#.*)?$/
-          var = $1
-          value = $2
+          var = ::Regexp.last_match(1)
+          value = ::Regexp.last_match(2)
           value.strip!
           raise(ArgumentError, _("Fileserver configuration file does not use '=' as a separator")) if value =~ /^=/
 

lib/puppet/file_serving/mount/file.rb

@@ -100,7 +100,7 @@ def expand(path, node = nil)
     end
 
     path.gsub(/%(.)/) do |v|
-      key = $1
+      key = ::Regexp.last_match(1)
       if key == "%"
         "%"
       else

lib/puppet/functions/defined.rb

@@ -112,7 +112,7 @@ def is_defined(scope, *vals) # rubocop:disable Naming/PredicateName
       case val
       when String
         if val =~ /^\$(.+)$/
-          scope.exist?($1)
+          scope.exist?(Regexp.last_match(1))
         else
           case val
           when ''

lib/puppet/indirector/terminus.rb

@@ -101,7 +101,7 @@ def model
 
     # Convert a short name to a constant.
     def name2const(name)
-      name.to_s.capitalize.sub(/_(.)/) { |_i| $1.upcase }
+      name.to_s.capitalize.sub(/_(.)/) { |_i| ::Regexp.last_match(1).upcase }
     end
 
     # Register a class, probably autoloaded.

lib/puppet/parser/scope.rb

@@ -283,8 +283,8 @@ def include?(name)
   def exist?(name)
     # Note !! ensure the answer is boolean
     !!if name =~ /^(.*)::(.+)$/
-        class_name = $1
-        variable_name = $2
+        class_name = ::Regexp.last_match(1)
+        variable_name = ::Regexp.last_match(2)
         return true if class_name == '' && BUILT_IN_VARS.include?(variable_name)
 
         # lookup class, but do not care if it is not evaluated since that will result
@@ -1046,7 +1046,7 @@ def find_defined_resource_type(type)
 
   def method_missing(method, *args, &block)
     method.to_s =~ /^function_(.*)$/
-    name = $1
+    name = ::Regexp.last_match(1)
     super unless name
     super unless Puppet::Parser::Functions.function(name)
     # In odd circumstances, this might not end up defined by the previous

lib/puppet/pops/lookup/hiera_config.rb

@@ -212,7 +212,7 @@ def configured_data_providers(lookup_invocation, parent_data_provider, use_defau
         # Raise a LookupError with a RUNTIME_ERROR issue to prevent this being translated to an evaluation error triggered in the pp file
         # where the lookup started
         if e.message =~ /^Undefined variable '([^']+)'/
-          var = $1
+          var = ::Regexp.last_match(1)
           fail(Issues::HIERA_UNDEFINED_VARIABLE, { :name => var }, find_line_matching(/%\{['"]?#{var}['"]?}/))
         end
         raise e

lib/puppet/pops/lookup/interpolation.rb

@@ -49,7 +49,7 @@ def interpolate_string(subject, context, allow_methods)
     lookup_invocation = context.is_a?(Invocation) ? context : context.invocation
     lookup_invocation.with(:interpolate, subject) do
       subject.gsub(/%\{([^\}]*)\}/) do |match|
-        expr = $1
+        expr = ::Regexp.last_match(1)
         # Leading and trailing spaces inside an interpolation expression are insignificant
         expr.strip!
         value = nil