Rubocop 0.50 and target 2.3.

Library/.rubocop.yml

@@ -1,5 +1,5 @@
 AllCops:
-  TargetRubyVersion: 2.0
+  TargetRubyVersion: 2.3
   Exclude:
     - '**/Casks/**/*'
     - '**/vendor/**/*'
@@ -119,7 +119,7 @@ Style/Encoding:
   Enabled: true
 
 # dashes in filenames are typical
-Style/FileName:
+Naming/FileName:
   Regex: !ruby/regexp /^[\w\@\-\+\.]+(\.rb)?$/
 
 # falsely flags e.g. curl formatting arguments as format strings
@@ -189,8 +189,25 @@ Style/TrailingCommaInArguments:
   EnforcedStyleForMultiline: comma
 
 # we have too many variables like sha256 where this harms readability
-Style/VariableNumber:
+Naming/VariableNumber:
   Enabled: false
 
 Style/WordArray:
   MinSize: 4
+
+# we want to add this slowly and manually
+Style/FrozenStringLiteralComment:
+  Enabled: false
+
+# generally rescuing StandardError is fine
+Lint/RescueWithoutErrorClass:
+  Enabled: false
+
+# implicitly allow EOS as we use it everywhere
+Naming/HeredocDelimiterNaming:
+  Blacklist:
+    - END, EOD, EOF
+
+# we output how to use interpolated strings too often
+Lint/InterpolationCheck:
+  Enabled: false

Library/Homebrew/.rubocop.yml

@@ -42,12 +42,12 @@ Style/HashSyntax:
   EnforcedStyle: ruby19_no_mixed_keys
 
 # we won't change backward compatible method names
-Style/MethodName:
+Naming/MethodName:
   Exclude:
     - 'compat/**/*'
 
 # we won't change backward compatible predicate names
-Style/PredicateName:
+Naming/PredicateName:
   Exclude:
     - 'compat/**/*'
   NameWhitelist: is_32_bit?, is_64_bit?

Library/Homebrew/.rubocop_todo.yml

@@ -81,7 +81,7 @@ Security/MarshalLoad:
     - 'utils/fork.rb'
 
 # Offense count: 1
-Style/AccessorMethodName:
+Naming/AccessorMethodName:
   Exclude:
     - 'extend/ENV/super.rb'
 
@@ -136,10 +136,3 @@ Style/MutableConstant:
     - 'formulary.rb'
     - 'tab.rb'
     - 'tap.rb'
-
-# Offense count: 8
-Style/OpMethod:
-  Exclude:
-    - 'dependencies.rb'
-    - 'install_renamed.rb'
-    - 'options.rb'

Library/Homebrew/constants.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # RuboCop version used for `brew style` and `brew cask style`
-HOMEBREW_RUBOCOP_VERSION = "0.49.1".freeze
+HOMEBREW_RUBOCOP_VERSION = "0.50.0"
-HOMEBREW_RUBOCOP_CASK_VERSION = "~> 0.13.1".freeze # has to be updated when RuboCop version changes
+HOMEBREW_RUBOCOP_CASK_VERSION = "~> 0.14.2" # has to be updated when RuboCop version changes

Library/Homebrew/os/mac.rb

@@ -11,7 +11,7 @@ module OS
   module Mac
     module_function
 
-    ::MacOS = self # rubocop:disable Style/ConstantName
+    ::MacOS = self # rubocop:disable Naming/ConstantName
 
     raise "Loaded OS::Mac on generic OS!" if ENV["HOMEBREW_TEST_GENERIC_OS"]