Fix Rubocop new warnings

.rubocop.yml

@@ -14,6 +14,10 @@ AllCops:
     - 'test/benchmarks/**/*'
     - 'test/profilers/**/*'
 
+# I often use @_variable to avoid clashing.
+Naming/MemoizedInstanceVariableName:
+  Enabled: false
+
 Style/ClassAndModuleChildren:
   Exclude:
     - 'spec/**/*_spec.rb'

lib/public_suffix/list.rb

@@ -212,7 +212,7 @@ def select(name, ignore_private: false)
 
       rules
     end
-    private :select
+    private :select # rubocop:disable Style/AccessModifierDeclarations
 
     # Gets the default rule.
     #

test/psl_test.rb

@@ -5,7 +5,7 @@
 # the definitions satisfies the test suite.
 class PslTest < Minitest::Test
 
-  ROOT = File.expand_path("../../", __FILE__)
+  ROOT = File.expand_path("..", __dir__)
 
   # rubocop:disable Security/Eval
   def self.tests

test/test_helper.rb

@@ -9,5 +9,5 @@
 
 Minitest::Reporters.use! Minitest::Reporters::DefaultReporter.new(color: true)
 
-$LOAD_PATH.unshift File.expand_path("../../lib", __FILE__)
+$LOAD_PATH.unshift File.expand_path("../lib", __dir__)
 require "public_suffix"