Merge pull request #3183 from MikeMcQuaid/rubocop-upgrade

Rubocop: 0.50.0 and Ruby 2.3

47 files changed, 118 insertions, 123 deletions

diff --git a/Library/.rubocop.yml b/Library/.rubocop.yml
index cb065a1a4..dd6e039b0 100644
--- a/Library/.rubocop.yml
+++ b/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
diff --git a/Library/Homebrew/.rubocop.yml b/Library/Homebrew/.rubocop.yml
index 26c944529..dc4406527 100644
--- a/Library/Homebrew/.rubocop.yml
+++ b/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?
diff --git a/Library/Homebrew/.rubocop_todo.yml b/Library/Homebrew/.rubocop_todo.yml
index 37518a5f0..96c2f3676 100644
--- a/Library/Homebrew/.rubocop_todo.yml
+++ b/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'
diff --git a/Library/Homebrew/brew.rb b/Library/Homebrew/brew.rb
index ec86bd794..2906fd93d 100644
--- a/Library/Homebrew/brew.rb
+++ b/Library/Homebrew/brew.rb
@@ -105,18 +105,16 @@ begin
     possible_tap = OFFICIAL_CMD_TAPS.find { |_, cmds| cmds.include?(cmd) }
     possible_tap = Tap.fetch(possible_tap.first) if possible_tap
 
-    if possible_tap && !possible_tap.installed?
-      brew_uid = HOMEBREW_BREW_FILE.stat.uid
-      tap_commands = []
-      if Process.uid.zero? && !brew_uid.zero?
-        tap_commands += %W[/usr/bin/sudo -u ##{brew_uid}]
-      end
-      tap_commands += %W[#{HOMEBREW_BREW_FILE} tap #{possible_tap}]
-      safe_system(*tap_commands)
-      exec HOMEBREW_BREW_FILE, cmd, *ARGV
-    else
-      odie "Unknown command: #{cmd}"
+    odie "Unknown command: #{cmd}" if !possible_tap || possible_tap.installed?
+
+    brew_uid = HOMEBREW_BREW_FILE.stat.uid
+    tap_commands = []
+    if Process.uid.zero? && !brew_uid.zero?
+      tap_commands += %W[/usr/bin/sudo -u ##{brew_uid}]
     end
+    tap_commands += %W[#{HOMEBREW_BREW_FILE} tap #{possible_tap}]
+    safe_system(*tap_commands)
+    exec HOMEBREW_BREW_FILE, cmd, *ARGV
   end
 rescue UsageError => e
   require "cmd/help"
diff --git a/Library/Homebrew/cask/lib/hbc/cask_loader.rb b/Library/Homebrew/cask/lib/hbc/cask_loader.rb
index 532d9f3c3..8fce9636a 100644
--- a/Library/Homebrew/cask/lib/hbc/cask_loader.rb
+++ b/Library/Homebrew/cask/lib/hbc/cask_loader.rb
@@ -56,7 +56,7 @@ module Hbc
 
     class FromURILoader < FromPathLoader
       def self.can_load?(ref)
-        ref.to_s.match?(::URI.regexp)
+        ref.to_s.match?(::URI::DEFAULT_PARSER.make_regexp)
       end
 
       attr_reader :url
diff --git a/Library/Homebrew/cask/lib/hbc/container/naked.rb b/Library/Homebrew/cask/lib/hbc/container/naked.rb
index 375d62f7a..dc265c402 100644
--- a/Library/Homebrew/cask/lib/hbc/container/naked.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/naked.rb
@@ -16,7 +16,7 @@ module Hbc
 
       def target_file
         return @path.basename if @nested
-        URI.decode(File.basename(@cask.url.path))
+        CGI.unescape(File.basename(@cask.url.path))
       end
     end
   end
diff --git a/Library/Homebrew/cask/lib/hbc/dsl.rb b/Library/Homebrew/cask/lib/hbc/dsl.rb
index 2dda47627..3824b9761 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl.rb
@@ -161,7 +161,7 @@ module Hbc
         begin
           DSL::Container.new(*args).tap do |container|
             # TODO: remove this backward-compatibility section after removing nested_container
-            if container && container.nested
+            if container&.nested
               artifacts[:nested_container] << Artifact::NestedContainer.new(cask, container.nested)
             end
           end
diff --git a/Library/Homebrew/cask/lib/hbc/dsl/version.rb b/Library/Homebrew/cask/lib/hbc/dsl/version.rb
index d73205f52..9605feb57 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl/version.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl/version.rb
@@ -49,7 +49,7 @@ module Hbc
         end
       end
 
-      DIVIDERS.keys.each do |divider|
+      DIVIDERS.each_key do |divider|
         define_divider_methods(divider)
       end
 
diff --git a/Library/Homebrew/cask/lib/hbc/installer.rb b/Library/Homebrew/cask/lib/hbc/installer.rb
index b9c34e3a1..01aae935d 100644
--- a/Library/Homebrew/cask/lib/hbc/installer.rb
+++ b/Library/Homebrew/cask/lib/hbc/installer.rb
@@ -159,7 +159,7 @@ module Hbc
       odebug "Extracting primary container"
 
       FileUtils.mkdir_p @cask.staged_path
-      container = if @cask.container && @cask.container.type
+      container = if @cask.container&.type
         Container.from_type(@cask.container.type)
       else
         Container.for_path(@downloaded_path, @command)
@@ -361,7 +361,7 @@ module Hbc
 
       savedir = @cask.metadata_subdir("Casks", timestamp: :now, create: true)
       FileUtils.copy @cask.sourcefile_path, savedir
-      old_savedir.rmtree unless old_savedir.nil?
+      old_savedir&.rmtree
     end
 
     def uninstall
diff --git a/Library/Homebrew/cask/lib/hbc/system_command.rb b/Library/Homebrew/cask/lib/hbc/system_command.rb
index b735ae4f9..be083c29e 100644
--- a/Library/Homebrew/cask/lib/hbc/system_command.rb
+++ b/Library/Homebrew/cask/lib/hbc/system_command.rb
@@ -61,7 +61,7 @@ module Hbc
     end
 
     def assert_success
-      return if processed_status && processed_status.success?
+      return if processed_status&.success?
       raise CaskCommandFailedError.new(command, processed_output[:stdout], processed_output[:stderr], processed_status)
     end
 
diff --git a/Library/Homebrew/caveats.rb b/Library/Homebrew/caveats.rb
index 578b292fa..1849ea79b 100644
--- a/Library/Homebrew/caveats.rb
+++ b/Library/Homebrew/caveats.rb
@@ -163,7 +163,7 @@ class Caveats
 
   def plist_caveats
     s = []
-    if f.plist || (keg && keg.plist_installed?)
+    if f.plist || (keg&.plist_installed?)
       plist_domain = f.plist_path.basename(".plist")
 
       # we readlink because this path probably doesn't exist since caveats
diff --git a/Library/Homebrew/cmd/prune.rb b/Library/Homebrew/cmd/prune.rb
index 9fc6dbcd9..7ec2838ba 100644
--- a/Library/Homebrew/cmd/prune.rb
+++ b/Library/Homebrew/cmd/prune.rb
@@ -55,7 +55,7 @@ module Homebrew
       else
         n, d = ObserverPathnameExtension.counts
         print "Pruned #{n} symbolic links "
-        print "and #{d} directories " if d > 0
+        print "and #{d} directories " if d.positive?
         puts "from #{HOMEBREW_PREFIX}"
       end
     end
diff --git a/Library/Homebrew/cmd/search.rb b/Library/Homebrew/cmd/search.rb
index acee9817f..c01a11c10 100644
--- a/Library/Homebrew/cmd/search.rb
+++ b/Library/Homebrew/cmd/search.rb
@@ -67,7 +67,7 @@ module Homebrew
 
         ohai "Searching blacklisted, migrated and deleted formulae..."
         if reason = Homebrew::MissingFormula.reason(query, silent: true)
-          if count > 0
+          if count.positive?
             puts
             puts "If you meant #{query.inspect} specifically:"
           end
diff --git a/Library/Homebrew/cmd/tap-info.rb b/Library/Homebrew/cmd/tap-info.rb
index af087645d..cb0e0b387 100644
--- a/Library/Homebrew/cmd/tap-info.rb
+++ b/Library/Homebrew/cmd/tap-info.rb
@@ -64,10 +64,10 @@ module Homebrew
         if tap.installed?
           info += tap.pinned? ? "pinned" : "unpinned"
           info += ", private" if tap.private?
-          if (formula_count = tap.formula_files.size) > 0
+          if (formula_count = tap.formula_files.size).positive?
             info += ", #{Formatter.pluralize(formula_count, "formula")}"
           end
-          if (command_count = tap.command_files.size) > 0
+          if (command_count = tap.command_files.size).positive?
             info += ", #{Formatter.pluralize(command_count, "command")}"
           end
           info += ", no formulae/commands" if (formula_count + command_count).zero?
diff --git a/Library/Homebrew/cmd/unlinkapps.rb b/Library/Homebrew/cmd/unlinkapps.rb
index 7cae97e27..56dba3603 100644
--- a/Library/Homebrew/cmd/unlinkapps.rb
+++ b/Library/Homebrew/cmd/unlinkapps.rb
@@ -77,7 +77,7 @@ module Homebrew
   def unlinkapps_unlink?(target_app, opts = {})
     # Skip non-symlinks and symlinks that don't point into the Homebrew prefix.
     app = target_app.readlink.to_s if target_app.symlink?
-    return false unless app && app.start_with?(*UNLINKAPPS_PREFIXES)
+    return false unless app&.start_with?(*UNLINKAPPS_PREFIXES)
 
     if opts.fetch(:prune, false)
       !File.exist?(app) # Remove only broken symlinks in prune mode.
diff --git a/Library/Homebrew/constants.rb b/Library/Homebrew/constants.rb
index 23be70bcc..b122946c8 100644
--- a/Library/Homebrew/constants.rb
+++ b/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_CASK_VERSION = "~> 0.13.1".freeze # has to be updated when RuboCop version changes
+HOMEBREW_RUBOCOP_VERSION = "0.50.0"
+HOMEBREW_RUBOCOP_CASK_VERSION = "~> 0.14.2" # has to be updated when RuboCop version changes
diff --git a/Library/Homebrew/debrew.rb b/Library/Homebrew/debrew.rb
index c2662c9ee..5bc3d2daa 100644
--- a/Library/Homebrew/debrew.rb
+++ b/Library/Homebrew/debrew.rb
@@ -57,7 +57,7 @@ module Debrew
         input.chomp!
 
         i = input.to_i
-        if i > 0
+        if i.positive?
           choice = menu.entries[i - 1]
         else
           possible = menu.entries.find_all { |e| e.name.start_with?(input) }
diff --git a/Library/Homebrew/debrew/irb.rb b/Library/Homebrew/debrew/irb.rb
index f97403782..069dbe676 100644
--- a/Library/Homebrew/debrew/irb.rb
+++ b/Library/Homebrew/debrew/irb.rb
@@ -16,7 +16,7 @@ module IRB
       workspace = WorkSpace.new(binding)
       irb = Irb.new(workspace)
 
-      @CONF[:IRB_RC].call(irb.context) if @CONF[:IRB_RC]
+      @CONF[:IRB_RC]&.call(irb.context)
       @CONF[:MAIN_CONTEXT] = irb.context
 
       trap("SIGINT") do
diff --git a/Library/Homebrew/dependency.rb b/Library/Homebrew/dependency.rb
index d7d5ec59c..0fbc2625b 100644
--- a/Library/Homebrew/dependency.rb
+++ b/Library/Homebrew/dependency.rb
@@ -51,7 +51,7 @@ class Dependency
   end
 
   def modify_build_environment
-    env_proc.call unless env_proc.nil?
+    env_proc&.call
   end
 
   def inspect
diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index 743b9484e..a7d498c0d 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -358,7 +358,7 @@ class FormulaAuditor
       end
       valid_alias_names = [alias_name_major, alias_name_major_minor]
 
-      if formula.tap && !formula.tap.core_tap?
+      unless formula.tap&.core_tap?
         versioned_aliases.map! { |a| "#{formula.tap}/#{a}" }
         valid_alias_names.map! { |a| "#{formula.tap}/#{a}" }
       end
@@ -707,7 +707,7 @@ class FormulaAuditor
     end
 
     stable = formula.stable
-    case stable && stable.url
+    case stable&.url
     when /[\d\._-](alpha|beta|rc\d)/
       matched = Regexp.last_match(1)
       version_prefix = stable.version.to_s.sub(/\d+$/, "")
@@ -1018,7 +1018,7 @@ class FormulaAuditor
   def audit_reverse_migration
     # Only enforce for new formula being re-added to core and official taps
     return unless @strict
-    return unless formula.tap && formula.tap.official?
+    return unless formula.tap&.official?
     return unless formula.tap.tap_migrations.key?(formula.name)
 
     problem <<-EOS.undent
diff --git a/Library/Homebrew/dev-cmd/bottle.rb b/Library/Homebrew/dev-cmd/bottle.rb
index d8aefc4c0..8dfd0d12c 100644
--- a/Library/Homebrew/dev-cmd/bottle.rb
+++ b/Library/Homebrew/dev-cmd/bottle.rb
@@ -47,7 +47,7 @@ BOTTLE_ERB = <<-EOS.freeze
     <% elsif cellar != BottleSpecification::DEFAULT_CELLAR %>
     cellar "<%= cellar %>"
     <% end %>
-    <% if rebuild > 0 %>
+    <% if rebuild.positive? %>
     rebuild <%= rebuild %>
     <% end %>
     <% checksums.each do |checksum_type, checksum_values| %>
@@ -186,7 +186,7 @@ module Homebrew
       ohai "Determining #{f.full_name} bottle rebuild..."
       versions = FormulaVersions.new(f)
       rebuilds = versions.bottle_version_map("origin/master")[f.pkg_version]
-      rebuilds.pop if rebuilds.last.to_i > 0
+      rebuilds.pop if rebuilds.last.to_i.positive?
       rebuild = rebuilds.empty? ? 0 : rebuilds.max.to_i + 1
     end
 
@@ -283,7 +283,7 @@ module Homebrew
         raise
       ensure
         ignore_interrupts do
-          original_tab.write if original_tab
+          original_tab&.write
           unless ARGV.include? "--skip-relocation"
             keg.replace_placeholders_with_locations changed_files
           end
diff --git a/Library/Homebrew/dev-cmd/bump-formula-pr.rb b/Library/Homebrew/dev-cmd/bump-formula-pr.rb
index 521c76302..21abed7d9 100644
--- a/Library/Homebrew/dev-cmd/bump-formula-pr.rb
+++ b/Library/Homebrew/dev-cmd/bump-formula-pr.rb
@@ -89,7 +89,7 @@ module Homebrew
 
   def check_for_duplicate_pull_requests(formula)
     pull_requests = fetch_pull_requests(formula)
-    return unless pull_requests && !pull_requests.empty?
+    return unless pull_requests&.empty?
     duplicates_message = <<-EOS.undent
       These open pull requests may be duplicates:
       #{pull_requests.map { |pr| "#{pr["title"]} #{pr["html_url"]}" }.join("\n")}
@@ -124,7 +124,7 @@ module Homebrew
       Formula.each do |f|
         if is_devel && f.devel && f.devel.url && f.devel.url.match(base_url)
           guesses << f
-        elsif f.stable && f.stable.url && f.stable.url.match(base_url)
+        elsif f.stable&.url && f.stable.url.match(base_url)
           guesses << f
         end
       end
diff --git a/Library/Homebrew/dev-cmd/pull.rb b/Library/Homebrew/dev-cmd/pull.rb
index a8f35531f..cd0d6fbd0 100644
--- a/Library/Homebrew/dev-cmd/pull.rb
+++ b/Library/Homebrew/dev-cmd/pull.rb
@@ -69,13 +69,13 @@ module Homebrew
     tap = nil
 
     ARGV.named.each do |arg|
-      if arg.to_i > 0
+      if arg.to_i.positive?
         issue = arg
         url = "https://github.com/Homebrew/homebrew-core/pull/#{arg}"
         tap = CoreTap.instance
       elsif (testing_match = arg.match %r{/job/Homebrew.*Testing/(\d+)/})
         tap = ARGV.value("tap")
-        tap = if tap && tap.start_with?("homebrew/")
+        tap = if tap&.start_with?("homebrew/")
           Tap.fetch("homebrew", tap.strip_prefix("homebrew/"))
         elsif tap
           odie "Tap option did not start with \"homebrew/\": #{tap}"
@@ -350,7 +350,7 @@ module Homebrew
       files << Regexp.last_match(1) if line =~ %r{^\+\+\+ b/(.*)}
     end
     files.each do |file|
-      if tap && tap.formula_file?(file)
+      if tap&.formula_file?(file)
         formula_name = File.basename(file, ".rb")
         formulae << formula_name unless formulae.include?(formula_name)
       else
diff --git a/Library/Homebrew/dev-cmd/release-notes.rb b/Library/Homebrew/dev-cmd/release-notes.rb
index e578869bf..496023956 100644
--- a/Library/Homebrew/dev-cmd/release-notes.rb
+++ b/Library/Homebrew/dev-cmd/release-notes.rb
@@ -10,10 +10,8 @@ module Homebrew
 
   def release_notes
     previous_tag = ARGV.named.first
-    unless previous_tag
-      previous_tag = Utils.popen_read("git tag --list --sort=-version:refname")
+    previous_tag ||= Utils.popen_read("git tag --list --sort=-version:refname")
                           .lines.first.chomp
-    end
     odie "Could not find any previous tags!" unless previous_tag
 
     end_ref = ARGV.named[1] || "origin/master"
diff --git a/Library/Homebrew/diagnostic.rb b/Library/Homebrew/diagnostic.rb
index ceb6ad4d1..88aa4dbc9 100644
--- a/Library/Homebrew/diagnostic.rb
+++ b/Library/Homebrew/diagnostic.rb
@@ -522,7 +522,7 @@ module Homebrew
         homebrew_owned = @found.all? do |path|
           Pathname.new(path).realpath.to_s.start_with? "#{HOMEBREW_CELLAR}/gettext"
         end
-        return if gettext && gettext.linked_keg.directory? && homebrew_owned
+        return if gettext&.linked_keg&.directory? && homebrew_owned
 
         inject_file_list @found, <<-EOS.undent
           gettext files detected at a system prefix.
@@ -540,7 +540,7 @@ module Homebrew
         rescue
           nil
         end
-        if libiconv && libiconv.linked_keg.directory?
+        if libiconv&.linked_keg&.directory?
           unless libiconv.keg_only?
             <<-EOS.undent
               A libiconv formula is installed and linked.
diff --git a/Library/Homebrew/exceptions.rb b/Library/Homebrew/exceptions.rb
index 8b4cddc59..5418f9331 100644
--- a/Library/Homebrew/exceptions.rb
+++ b/Library/Homebrew/exceptions.rb
@@ -416,7 +416,7 @@ class BuildError < RuntimeError
 
     puts
 
-    if issues && !issues.empty?
+    unless issues&.empty?
       puts "These open issues may also help:"
       puts issues.map { |i| "#{i["title"]} #{i["html_url"]}" }.join("\n")
     end
diff --git a/Library/Homebrew/extend/ARGV.rb b/Library/Homebrew/extend/ARGV.rb
index daa5306fa..63a0f3e40 100644
--- a/Library/Homebrew/extend/ARGV.rb
+++ b/Library/Homebrew/extend/ARGV.rb
@@ -144,7 +144,7 @@ module HomebrewArgvExtension
   def value(name)
     arg_prefix = "--#{name}="
     flag_with_value = find { |arg| arg.start_with?(arg_prefix) }
-    flag_with_value.strip_prefix(arg_prefix) if flag_with_value
+    flag_with_value&.strip_prefix(arg_prefix)
   end
 
   # Returns an array of values that were given as a comma-separated list.
@@ -236,7 +236,7 @@ module HomebrewArgvExtension
 
   def bottle_arch
     arch = value "bottle-arch"
-    arch.to_sym if arch
+    arch&.to_sym
   end
 
   def build_from_source?
diff --git a/Library/Homebrew/extend/ENV.rb b/Library/Homebrew/extend/ENV.rb
index 283e90b69..ea1b99501 100644
--- a/Library/Homebrew/extend/ENV.rb
+++ b/Library/Homebrew/extend/ENV.rb
@@ -28,7 +28,7 @@ module EnvActivation
   end
 
   def clear_sensitive_environment!
-    ENV.keys.each do |key|
+    ENV.each_key do |key|
       next unless /(cookie|key|token)/i =~ key
       ENV.delete key
     end
diff --git a/Library/Homebrew/extend/ENV/std.rb b/Library/Homebrew/extend/ENV/std.rb
index a2e800803..4e5d0683a 100644
--- a/Library/Homebrew/extend/ENV/std.rb
+++ b/Library/Homebrew/extend/ENV/std.rb
@@ -233,8 +233,8 @@ module Stdenv
 
   def make_jobs
     # '-j' requires a positive integral argument
-    if self["HOMEBREW_MAKE_JOBS"].to_i > 0
-      self["HOMEBREW_MAKE_JOBS"].to_i
+    if (jobs = self["HOMEBREW_MAKE_JOBS"].to_i).positive?
+      jobs
     else
       Hardware::CPU.cores
     end
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 2f0c913c2..d999b9c5f 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -472,7 +472,7 @@ class Formula
     return true if devel && tab.devel_version && tab.devel_version < devel.version
 
     if options[:fetch_head]
-      return false unless head && head.downloader.is_a?(VCSDownloadStrategy)
+      return false unless head&.downloader.is_a?(VCSDownloadStrategy)
       downloader = head.downloader
       downloader.shutup! unless ARGV.verbose?
       downloader.commit_outdated?(version.version.commit)
@@ -1115,8 +1115,8 @@ class Formula
 
   # @private
   def unlock
-    @lock.unlock unless @lock.nil?
-    @oldname_lock.unlock unless @oldname_lock.nil?
+    @lock&.unlock
+    @oldname_lock&.unlock
   end
 
   def migration_needed?
@@ -1182,7 +1182,8 @@ class Formula
   # Returns false if the formula wasn't installed with an alias.
   def installed_alias_target_changed?
     target = current_installed_alias_target
-    target && target.name != name
+    return false unless target
+    target.name != name
   end
 
   # Is this formula the target of an alias used to install an old formula?
@@ -1440,13 +1441,14 @@ class Formula
   # True if this formula is provided by Homebrew itself
   # @private
   def core_formula?
-    tap && tap.core_tap?
+    tap&.core_tap?
   end
 
   # True if this formula is provided by external Tap
   # @private
   def tap?
-    tap && !tap.core_tap?
+    return false unless tap
+    !tap.core_tap?
   end
 
   # @private
@@ -1525,10 +1527,10 @@ class Formula
       "oldname" => oldname,
       "aliases" => aliases,
       "versions" => {
-        "stable" => (stable.version.to_s if stable),
+        "stable" => stable&.version.to_s,
         "bottle" => bottle ? true : false,
-        "devel" => (devel.version.to_s if devel),
-        "head" => (head.version.to_s if head),
+        "devel" => devel&.version.to_s,
+        "head" => head&.version.to_s,
       },
       "revision" => revision,
       "version_scheme" => version_scheme,
@@ -1570,7 +1572,7 @@ class Formula
         "root_url" => bottle_spec.root_url,
       }
       bottle_info["files"] = {}
-      bottle_spec.collector.keys.each do |os|
+      bottle_spec.collector.keys.each do |os| # rubocop:disable Performance/HashEachMethods
         checksum = bottle_spec.collector[os]
         bottle_info["files"][os] = {
           "url" => "#{bottle_spec.root_url}/#{Bottle::Filename.create(self, os, bottle_spec.rebuild)}",
diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index e955dcf07..b4f9db845 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -269,7 +269,7 @@ class FormulaInstaller
       oh1 "Installing #{Formatter.identifier(formula.full_name)} #{options}".strip
     end
 
-    if formula.tap && !formula.tap.private?
+    unless formula.tap&.private?
       action = "#{formula.full_name} #{options}".strip
       Utils::Analytics.report_event("install", action)
 
@@ -560,7 +560,7 @@ class FormulaInstaller
     end
     raise
   else
-    ignore_interrupts { tmp_keg.rmtree if tmp_keg && tmp_keg.directory? }
+    ignore_interrupts { tmp_keg.rmtree if tmp_keg&.directory? }
   end
 
   def caveats
diff --git a/Library/Homebrew/install_renamed.rb b/Library/Homebrew/install_renamed.rb
index 5e200244f..dc5d4cda8 100644
--- a/Library/Homebrew/install_renamed.rb
+++ b/Library/Homebrew/install_renamed.rb
@@ -16,12 +16,12 @@ module InstallRenamed
     end
   end
 
-  def +(path)
-    super(path).extend(InstallRenamed)
+  def +(other)
+    super(other).extend(InstallRenamed)
   end
 
-  def /(path)
-    super(path).extend(InstallRenamed)
+  def /(other)
+    super(other).extend(InstallRenamed)
   end
 
   private
diff --git a/Library/Homebrew/keg.rb b/Library/Homebrew/keg.rb
index 92eab7ad3..677a97c85 100644
--- a/Library/Homebrew/keg.rb
+++ b/Library/Homebrew/keg.rb
@@ -338,7 +338,7 @@ class Keg
       dir if dir.directory? && dir.children.any? { |f| f.basename.to_s.start_with?("_") }
     when :fish then path/"share/fish/vendor_completions.d"
     end
-    dir && dir.directory? && !dir.children.empty?
+    dir&.directory? && !dir.children.empty?
   end
 
   def functions_installed?(shell)
diff --git a/Library/Homebrew/language/python.rb b/Library/Homebrew/language/python.rb
index 0f8e3a4e6..bfec556d0 100644
--- a/Library/Homebrew/language/python.rb
+++ b/Library/Homebrew/language/python.rb
@@ -23,7 +23,7 @@ module Language
         else
           homebrew_site_packages(version)
         end
-        block.call python, version if block
+        block&.call python, version
       end
       ENV["PYTHONPATH"] = original_pythonpath
     end
diff --git a/Library/Homebrew/locale.rb b/Library/Homebrew/locale.rb
index 5e778f3b4..d918e2a2a 100644
--- a/Library/Homebrew/locale.rb
+++ b/Library/Homebrew/locale.rb
@@ -44,8 +44,6 @@ class Locale
       raise ParserError, "'#{value}' does not match #{regex}" unless value =~ regex
       instance_variable_set(:"@#{key}", value)
     end
-
-    self
   end
 
   def include?(other)
diff --git a/Library/Homebrew/options.rb b/Library/Homebrew/options.rb
index 9f1253531..05dd643ff 100644
--- a/Library/Homebrew/options.rb
+++ b/Library/Homebrew/options.rb
@@ -69,29 +69,29 @@ class Options
     @options.each(*args, &block)
   end
 
-  def <<(o)
-    @options << o
+  def <<(other)
+    @options << other
     self
   end
 
-  def +(o)
-    self.class.new(@options + o)
+  def +(other)
+    self.class.new(@options + other)
   end
 
-  def -(o)
-    self.class.new(@options - o)
+  def -(other)
+    self.class.new(@options - other)
   end
 
-  def &(o)
-    self.class.new(@options & o)
+  def &(other)
+    self.class.new(@options & other)
   end
 
-  def |(o)
-    self.class.new(@options | o)
+  def |(other)
+    self.class.new(@options | other)
   end
 
-  def *(arg)
-    @options.to_a * arg
+  def *(other)
+    @options.to_a * other
   end
 
   def empty?
diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index 52fa2a187..15c301f99 100644
--- a/Library/Homebrew/os/mac.rb
+++ b/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"]
 
@@ -104,7 +104,7 @@ module OS
     # Returns the path to an SDK or nil, following the rules set by #sdk.
     def sdk_path(v = nil)
       s = sdk(v)
-      s.path unless s.nil?
+      s&.path
     end
 
     # See these issues for some history:
diff --git a/Library/Homebrew/pkg_version.rb b/Library/Homebrew/pkg_version.rb
index 761a349fd..b68d78cf8 100644
--- a/Library/Homebrew/pkg_version.rb
+++ b/Library/Homebrew/pkg_version.rb
@@ -23,7 +23,7 @@ class PkgVersion
   end
 
   def to_s
-    if revision > 0
+    if revision.positive?
       "#{version}_#{revision}"
     else
       version.to_s
diff --git a/Library/Homebrew/requirements/java_requirement.rb b/Library/Homebrew/requirements/java_requirement.rb
index ab6dca51d..de3a33eb4 100644
--- a/Library/Homebrew/requirements/java_requirement.rb
+++ b/Library/Homebrew/requirements/java_requirement.rb
@@ -69,14 +69,14 @@ class JavaRequirement < Requirement
     rescue FormulaUnavailableError
       nil
     end
-    javas << jdk.bin/"java" if jdk && jdk.installed?
+    javas << jdk.bin/"java" if jdk&.installed?
     javas << which("java")
     javas
   end
 
   def preferred_java
     possible_javas.detect do |java|
-      next false unless java && java.executable?
+      next false unless java&.executable?
       next true unless @version
       next true if satisfies_version(java)
     end
diff --git a/Library/Homebrew/requirements/ruby_requirement.rb b/Library/Homebrew/requirements/ruby_requirement.rb
index acc655924..a9ec8c42d 100644
--- a/Library/Homebrew/requirements/ruby_requirement.rb
+++ b/Library/Homebrew/requirements/ruby_requirement.rb
@@ -41,9 +41,7 @@ class RubyRequirement < Requirement
   def rubies
     rubies = which_all("ruby")
     ruby_formula = Formula["ruby"]
-    if ruby_formula && ruby_formula.installed?
-      rubies.unshift ruby_formula.bin/"ruby"
-    end
+    rubies.unshift ruby_formula.bin/"ruby" if ruby_formula&.installed?
     rubies.uniq
   end
 
diff --git a/Library/Homebrew/rubocops/components_order_cop.rb b/Library/Homebrew/rubocops/components_order_cop.rb
index f1179d9a4..3bf2ede16 100644
--- a/Library/Homebrew/rubocops/components_order_cop.rb
+++ b/Library/Homebrew/rubocops/components_order_cop.rb
@@ -87,8 +87,8 @@ module RuboCop
           # preceding_comp_arr: array containing components of same type
           order_idx, curr_p_idx, preceding_comp_arr = get_state(node1)
 
-          # curr_p_idx > 0 means node1 needs to be grouped with its own kind
-          if curr_p_idx > 0
+          # curr_p_idx.positive? means node1 needs to be grouped with its own kind
+          if curr_p_idx.positive?
             node2 = preceding_comp_arr[curr_p_idx - 1]
             indentation = " " * (start_column(node2) - line_start_column(node2))
             line_breaks = node2.multiline? ? "\n\n" : "\n"
diff --git a/Library/Homebrew/sandbox.rb b/Library/Homebrew/sandbox.rb
index 8c662857e..7d23e5966 100644
--- a/Library/Homebrew/sandbox.rb
+++ b/Library/Homebrew/sandbox.rb
@@ -167,7 +167,7 @@ class Sandbox
 
     def add_rule(rule)
       s = "("
-      s << ((rule[:allow]) ? "allow" : "deny")
+      s << (rule[:allow] ? "allow" : "deny")
       s << " #{rule[:operation]}"
       s << " (#{rule[:filter]})" if rule[:filter]
       s << " (with #{rule[:modifier]})" if rule[:modifier]
diff --git a/Library/Homebrew/software_spec.rb b/Library/Homebrew/software_spec.rb
index 49d818f0f..dd6026fcf 100644
--- a/Library/Homebrew/software_spec.rb
+++ b/Library/Homebrew/software_spec.rb
@@ -267,7 +267,7 @@ class Bottle
     end
 
     def suffix
-      s = (rebuild > 0) ? ".#{rebuild}" : ""
+      s = rebuild.positive? ? ".#{rebuild}" : ""
       ".bottle#{s}.tar.gz"
     end
   end
diff --git a/Library/Homebrew/tab.rb b/Library/Homebrew/tab.rb
index e7df88356..af19cabe6 100644
--- a/Library/Homebrew/tab.rb
+++ b/Library/Homebrew/tab.rb
@@ -324,7 +324,7 @@ class Tab < OpenStruct
       "poured_from_bottle" => poured_from_bottle,
       "installed_as_dependency" => installed_as_dependency,
       "installed_on_request" => installed_on_request,
-      "changed_files" => changed_files && changed_files.map(&:to_s),
+      "changed_files" => changed_files&.map(&:to_s),
       "time" => time,
       "source_modified_time" => source_modified_time.to_i,
       "HEAD" => self.HEAD,
diff --git a/Library/Homebrew/tap.rb b/Library/Homebrew/tap.rb
index f6246aad9..f4e7631b4 100644
--- a/Library/Homebrew/tap.rb
+++ b/Library/Homebrew/tap.rb
@@ -648,6 +648,5 @@ class TapConfig
     tap.path.cd do
       safe_system "git", "config", "--local", "--replace-all", "homebrew.#{key}", value.to_s
     end
-    value
   end
 end
diff --git a/Library/Homebrew/utils/github.rb b/Library/Homebrew/utils/github.rb
index a50d6d8e5..df0811e95 100644
--- a/Library/Homebrew/utils/github.rb
+++ b/Library/Homebrew/utils/github.rb
@@ -86,15 +86,9 @@ module GitHub
 
   def api_credentials_type
     token, username = api_credentials
-    if token && !token.empty?
-      if username && !username.empty?
-        :keychain
-      else
-        :environment
-      end
-    else
-      :none
-    end
+    return :none if !token || token.empty?
+    return :keychain if !username || username.empty?
+    :environment
   end
 
   def api_credentials_error_message(response_headers, needed_scopes)
diff --git a/Library/Homebrew/utils/shell.rb b/Library/Homebrew/utils/shell.rb
index 5327f6ecf..8c1c5f984 100644
--- a/Library/Homebrew/utils/shell.rb
+++ b/Library/Homebrew/utils/shell.rb
@@ -51,8 +51,6 @@ module Utils
       end
     end
 
-    private
-
     SHELL_PROFILE_MAP = {
       bash: "~/.bash_profile",
       csh: "~/.cshrc",
@@ -65,8 +63,6 @@ module Utils
 
     UNSAFE_SHELL_CHAR = %r{([^A-Za-z0-9_\-.,:/@\n])}
 
-    module_function
-
     def csh_quote(str)
       # ruby's implementation of shell_escape
       str = str.to_s