Use ActiveSupport’s #second.

Library/Homebrew/brew.rb

@@ -5,9 +5,7 @@ end
 std_trap = trap("INT") { exit! 130 } # no backtrace thanks
 
 # check ruby version before requiring any modules.
-RUBY_VERSION_SPLIT = RUBY_VERSION.split "."
+RUBY_X, RUBY_Y, = RUBY_VERSION.split(".").map(&:to_i)
-RUBY_X = RUBY_VERSION_SPLIT[0].to_i
-RUBY_Y = RUBY_VERSION_SPLIT[1].to_i
 if RUBY_X < 2 || (RUBY_X == 2 && RUBY_Y < 3)
   raise "Homebrew must be run under Ruby 2.3! You're running #{RUBY_VERSION}."
 end

Library/Homebrew/cask/artifact/abstract_uninstall.rb

@@ -115,10 +115,8 @@ module Cask
         command.run!("/bin/launchctl", args: ["list"]).stdout.lines
                .map { |line| line.chomp.split("\t") }
                .map { |pid, state, id| [pid.to_i, state.to_i, id] }
-               .select do |fields|
+               .select do |(pid, _, id)|
-                 next if fields[0].zero?
+                 pid.nonzero? && id.match?(/^#{Regexp.escape(bundle_id)}($|\.\d+)/)
-
-                 fields[2] =~ /^#{Regexp.escape(bundle_id)}($|\.\d+)/
                end
       end
 

Library/Homebrew/cask/dsl/version.rb

@@ -89,19 +89,19 @@ module Cask
       end
 
       def before_comma
-        version { split(",", 2)[0] }
+        version { split(",", 2).first }
       end
 
       def after_comma
-        version { split(",", 2)[1] }
+        version { split(",", 2).second }
       end
 
       def before_colon
-        version { split(":", 2)[0] }
+        version { split(":", 2).first }
       end
 
       def after_colon
-        version { split(":", 2)[1] }
+        version { split(":", 2).second }
       end
 
       def no_dividers

Library/Homebrew/cmd/switch.rb

@@ -28,7 +28,7 @@ module Homebrew
                    .map { |d| Keg.new(d).version }
                    .sort
                    .join(", ")
-    version = ARGV[1]
+    version = ARGV.second
 
     if !version || ARGV.named.length > 2
       onoe usage

Library/Homebrew/cmd/tap.rb

@@ -45,9 +45,9 @@ module Homebrew
     elsif ARGV.named.empty?
       puts Tap.names
     else
-      tap = Tap.fetch(ARGV.named[0])
+      tap = Tap.fetch(ARGV.named.first)
       begin
-        tap.install clone_target: ARGV.named[1],
+        tap.install clone_target: ARGV.named.second,
                     force_auto_update: force_auto_update?,
                     full_clone: full_clone?,
                     quiet: ARGV.quieter?

Library/Homebrew/dev-cmd/audit.rb

@@ -512,7 +512,7 @@ module Homebrew
       # Formulae names can legitimately be uppercase/lowercase/both.
       name = Regexp.new(formula.name, Regexp::IGNORECASE)
       reason.sub!(name, "")
-      first_word = reason.split[0]
+      first_word = reason.split.first
 
       if reason =~ /\A[A-Z]/ && !reason.start_with?(*whitelist)
         problem <<~EOS
@@ -724,7 +724,7 @@ module Homebrew
 
         version = Version.parse(stable.url)
         if version >= Version.create("1.0")
-          minor_version = version.to_s.split(".", 3)[1].to_i
+          _, minor_version, = version.to_s.split(".", 3).map(&:to_i)
           if minor_version.odd?
             problem "#{stable.version} is a development release"
           end

Library/Homebrew/dev-cmd/extract.rb

@@ -120,7 +120,7 @@ module Homebrew
     # Expect exactly two named arguments: formula and tap
     raise UsageError if ARGV.named.length != 2
 
-    destination_tap = Tap.fetch(ARGV.named[1])
+    destination_tap = Tap.fetch(ARGV.named.second)
     odie "Cannot extract formula to homebrew/core!" if destination_tap.core_tap?
     destination_tap.install unless destination_tap.installed?
 

Library/Homebrew/dev-cmd/release-notes.rb

@@ -33,7 +33,7 @@ module Homebrew
     ).lines.first.chomp
     odie "Could not find any previous tags!" unless previous_tag
 
-    end_ref = ARGV.named[1] || "origin/master"
+    end_ref = ARGV.named.second || "origin/master"
 
     [previous_tag, end_ref].each do |ref|
       next if quiet_system "git", "-C", HOMEBREW_REPOSITORY, "rev-parse", "--verify", "--quiet", ref

Library/Homebrew/dev-cmd/update-test.rb

@@ -61,7 +61,7 @@ module Homebrew
         Utils.popen_read("git", "rev-list", "-n1", "--before=#{date}", "origin/master").chomp
       elsif args.to_tag?
         tags = Utils.popen_read("git", "tag", "--list", "--sort=-version:refname")
-        previous_tag = tags.lines[1]
+        previous_tag = tags.lines.second
         previous_tag ||= begin
           if (HOMEBREW_REPOSITORY/".git/shallow").exist?
             safe_system "git", "fetch", "--tags", "--depth=1"
@@ -69,7 +69,7 @@ module Homebrew
           elsif OS.linux?
             tags = Utils.popen_read("git tag --list | sort -rV")
           end
-          tags.lines[1]
+          tags.lines.second
         end
         previous_tag = previous_tag.to_s.chomp
         odie "Could not find previous tag in:\n#{tags}" if previous_tag.empty?

Library/Homebrew/exceptions.rb

@@ -105,7 +105,7 @@ module FormulaClassUnavailableErrorModule
   end
 
   def format_list(class_list)
-    class_list.map { |klass| klass.name.split("::")[-1] }.join(", ")
+    class_list.map { |klass| klass.name.split("::").last }.join(", ")
   end
 end
 

Library/Homebrew/formula.rb

@@ -417,7 +417,7 @@ class Formula
   def aliases
     @aliases ||= if tap
       tap.alias_reverse_table[full_name].to_a.map do |a|
-        a.split("/")[-1]
+        a.split("/").last
       end
     else
       []
@@ -1371,7 +1371,7 @@ class Formula
   # an array of all {Formula} names
   # @private
   def self.names
-    @names ||= (core_names + tap_names.map { |name| name.split("/")[-1] }).uniq.sort
+    @names ||= (core_names + tap_names.map { |name| name.split("/").last }).uniq.sort
   end
 
   # an array of all {Formula} files
@@ -1462,7 +1462,7 @@ class Formula
   # an array of all aliases
   # @private
   def self.aliases
-    @aliases ||= (core_aliases + tap_aliases.map { |name| name.split("/")[-1] }).uniq.sort
+    @aliases ||= (core_aliases + tap_aliases.map { |name| name.split("/").last }).uniq.sort
   end
 
   # an array of all aliases, , which the tap formulae have the fully-qualified name

Library/Homebrew/language/haskell.rb

@@ -71,9 +71,7 @@ module Language
         rm_rf Dir[".cabal-sandbox/*packages.conf.d/"]
       end
 
-      def install_cabal_package(*args)
+      def install_cabal_package(*args, **options)
-        options = args[-1].is_a?(Hash) ? args.pop : {}
-
         cabal_sandbox do
           cabal_install_tools(*options[:using]) if options[:using]
 

Library/Homebrew/tap.rb

@@ -17,8 +17,8 @@ class Tap
     when 1
       user, repo = args.first.split("/", 2)
     when 2
-      user = args[0]
+      user = args.first
-      repo = args[1]
+      repo = args.second
     end
 
     if [user, repo].any? { |part| part.nil? || part.include?("/") }

Library/Homebrew/test/cask/dsl_spec.rb

@@ -419,10 +419,10 @@ describe Cask::DSL, :cask do
       let(:token) { "with-installer-script" }
 
       it "allows installer script to be specified" do
-        expect(cask.artifacts.to_a[0].path).to eq(Pathname("/usr/bin/true"))
+        expect(cask.artifacts.to_a.first.path).to eq(Pathname("/usr/bin/true"))
-        expect(cask.artifacts.to_a[0].args[:args]).to eq(["--flag"])
+        expect(cask.artifacts.to_a.first.args[:args]).to eq(["--flag"])
-        expect(cask.artifacts.to_a[1].path).to eq(Pathname("/usr/bin/false"))
+        expect(cask.artifacts.to_a.second.path).to eq(Pathname("/usr/bin/false"))
-        expect(cask.artifacts.to_a[1].args[:args]).to eq(["--flag"])
+        expect(cask.artifacts.to_a.second.args[:args]).to eq(["--flag"])
       end
     end
 

Library/Homebrew/test/patch_spec.rb

@@ -86,8 +86,8 @@ describe Patch do
       )
 
       expect(patches.length).to eq(2)
-      expect(patches[0].strip).to eq(:p1)
+      expect(patches.first.strip).to eq(:p1)
-      expect(patches[1].strip).to eq(:p1)
+      expect(patches.second.strip).to eq(:p1)
     end
 
     it "can create patches from a :p0 hash" do

Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb

@@ -53,8 +53,9 @@ RSpec.shared_context "integration test" do
   def command_id_from_args(args)
     @command_count ||= 0
     pretty_args = args.join(" ").gsub(TEST_TMPDIR, "@TMPDIR@")
-    file_and_line = caller[1].sub(/(.*\d+):.*/, '\1')
+    file_and_line = caller.second
-                             .sub("#{HOMEBREW_LIBRARY_PATH}/test/", "")
+                          .sub(/(.*\d+):.*/, '\1')
+                          .sub("#{HOMEBREW_LIBRARY_PATH}/test/", "")
     "#{file_and_line}:brew #{pretty_args}:#{@command_count += 1}"
   end
 

Library/Homebrew/utils/bottles.rb

@@ -54,7 +54,7 @@ module Utils
       end
 
       def resolve_version(bottle_file)
-        PkgVersion.parse receipt_path(bottle_file).split("/")[1]
+        PkgVersion.parse receipt_path(bottle_file).split("/").second
       end
 
       def formula_contents(bottle_file,

Library/Homebrew/utils/tty.rb

@@ -7,8 +7,8 @@ module Tty
 
   def width
     @width ||= begin
-      width = `/bin/stty size 2>/dev/null`.split[1]
+      _, width = `/bin/stty size 2>/dev/null`.split
-      width = `/usr/bin/tput cols 2>/dev/null`.split[0] if width.to_i.zero?
+      width, = `/usr/bin/tput cols 2>/dev/null`.split if width.to_i.zero?
       width ||= 80
       width.to_i
     end

Library/Homebrew/version.rb

@@ -351,7 +351,7 @@ class Version
     # e.g. https://github.com/JustArchi/ArchiSteamFarm/releases/download/2.3.2.0/ASF.zip
     # e.g. https://people.gnome.org/~newren/eg/download/1.7.5.2/eg
     m = %r{/([rvV]_?)?(\d\.\d+(\.\d+){,2})}.match(spec_s)
-    return m.captures[1] unless m.nil?
+    return m.captures.second unless m.nil?
 
     # e.g. https://www.ijg.org/files/jpegsrc.v8d.tar.gz
     m = /\.v(\d+[a-z]?)/.match(stem)