avoid filesystem checks from Pathname presence tests

Library/Homebrew/attestation.rb

@@ -66,7 +66,7 @@ module Homebrew
     sig { returns(Pathname) }
     def self.gh_executable
       @gh_executable ||= T.let(nil, T.nilable(Pathname))
-      return @gh_executable if @gh_executable.present?
+      return @gh_executable if @gh_executable
 
       # NOTE: We set HOMEBREW_NO_VERIFY_ATTESTATIONS when installing `gh` itself,
       #       to prevent a cycle during bootstrapping. This can eventually be resolved

Library/Homebrew/brew.rb

@@ -77,7 +77,7 @@ begin
       # External commands expect a normal PATH
       ENV["PATH"] = homebrew_path.to_s
 
-      external_ruby_v2_cmd = Commands.external_ruby_v2_cmd_path(cmd).present?
+      external_ruby_v2_cmd = !Commands.external_ruby_v2_cmd_path(cmd).nil?
       external_ruby_cmd_path = Commands.external_ruby_cmd_path(cmd) unless external_ruby_v2_cmd
       external_cmd_path = Commands.external_cmd_path(cmd) if !external_ruby_v2_cmd && external_ruby_cmd_path.nil?
     end

Library/Homebrew/build.rb

@@ -238,7 +238,7 @@ class Build
     elsif formula.prefix.directory?
       formula.prefix
     elsif (children = formula.rack.children.presence) && children.size == 1 &&
-          (first_child = children.first.presence) && first_child.directory?
+          (first_child = children.first) && first_child.directory?
       first_child
     else
       raise

Library/Homebrew/bundle.rb

@@ -150,7 +150,7 @@ module Homebrew
 
           tab = Tab.for_name(name)
           tabfile = tab.tabfile
-          next if tabfile.blank? || !tabfile.exist?
+          next unless tabfile&.exist?
           next if tab.installed_on_request
 
           next name if use_brew_tab

Library/Homebrew/bundle/subcommand/exec.rb

@@ -169,7 +169,7 @@ module Homebrew
 
           # For commands which aren't either absolute or relative
           # Add the command directory to PATH, since it may get blown away by superenv
-          if command.exclude?("/") && (which_command = which(command)).present?
+          if command.exclude?("/") && (which_command = which(command))
             ENV.prepend_path "PATH", which_command.dirname.to_s
           end
 

Library/Homebrew/cleanup.rb

@@ -750,7 +750,7 @@ module Homebrew
 
         db.each_key do |keg|
           keg = T.cast(keg, String)
-          next if rack.present? && !keg.start_with?("#{rack}/")
+          next if rack && !keg.start_with?("#{rack}/")
           next if File.directory?(keg)
 
           LinkageCacheStore.new(

Library/Homebrew/cmd/info.rb

@@ -581,7 +581,7 @@ module Homebrew
           return cask.sourcefile_path.to_s if tap.blank? || tap.remote.blank?
 
           sourcefile_path = cask.sourcefile_path
-          if sourcefile_path.blank? || sourcefile_path.extname != ".rb"
+          if !sourcefile_path || sourcefile_path.extname != ".rb"
             return "#{tap.default_remote}/blob/HEAD/#{tap.relative_cask_path(cask.token)}"
           end
 

Library/Homebrew/cmd/tab.rb

@@ -65,15 +65,15 @@ module Homebrew
           cask = formula_or_cask
           cask_tab = cask.tab
           cask_tabfile = cask_tab.tabfile
-          if cask_tabfile.blank? || !cask_tabfile.exist?
-            [cask.token, Cask::Tab.create(cask), true]
-          else
+          if cask_tabfile&.exist?
             [cask.token, cask_tab, false]
+          else
+            [cask.token, Cask::Tab.create(cask), true]
           end
         end
 
         tabfile = tab.tabfile
-        if !created_tab && (tabfile.blank? || !tabfile.exist?)
+        if !created_tab && !tabfile&.exist?
           raise ArgumentError,
                 "Tab file for #{name} does not exist."
         end

Library/Homebrew/commands.rb

@@ -242,7 +242,7 @@ module Commands
     return if command == "help"
 
     path = self.path(command)
-    return if path.blank?
+    return unless path
 
     if (cmd_parser = Homebrew::CLI::Parser.from_cmd_path(path))
       processed_options = if subcommand.nil? && cmd_parser.subcommands.present?
@@ -275,7 +275,7 @@ module Commands
   sig { params(command: String, short: T::Boolean).returns(T.nilable(String)) }
   def self.command_description(command, short: false)
     path = self.path(command)
-    return if path.blank?
+    return unless path
 
     if (cmd_parser = Homebrew::CLI::Parser.from_cmd_path(path))
       if short
@@ -305,7 +305,7 @@ module Commands
   sig { params(command: String).returns(T::Array[Homebrew::CLI::Parser::Subcommand]) }
   def self.command_subcommands(command)
     path = self.path(command)
-    return [] if path.blank?
+    return [] unless path
 
     cmd_parser = Homebrew::CLI::Parser.from_cmd_path(path)
     return [] if cmd_parser.blank?
@@ -319,7 +319,7 @@ module Commands
   }
   def self.named_args_type(command, subcommand: nil)
     path = self.path(command)
-    return if path.blank?
+    return unless path
 
     cmd_parser = Homebrew::CLI::Parser.from_cmd_path(path)
     return if cmd_parser.blank?
@@ -336,7 +336,7 @@ module Commands
   sig { params(command: String, option: String).returns(T.nilable(T::Array[String])) }
   def self.option_conflicts(command, option)
     path = self.path(command)
-    return if path.blank?
+    return unless path
 
     cmd_parser = Homebrew::CLI::Parser.from_cmd_path(path)
     return if cmd_parser.blank?

Library/Homebrew/dev-cmd/bottle.rb

@@ -390,7 +390,7 @@ module Homebrew
 
       sig { params(formula: Formula).void }
       def bottle_formula(formula)
-        local_bottle_json = args.json? && formula.local_bottle_path.present?
+        local_bottle_json = args.json? && formula.local_bottle_path
 
         unless local_bottle_json
           unless formula.latest_version_installed?
@@ -458,7 +458,7 @@ module Homebrew
 
         if local_bottle_json
           bottle_path = formula.local_bottle_path
-          return if bottle_path.blank?
+          return unless bottle_path
 
           local_filename = bottle_path.basename.to_s
 

Library/Homebrew/dev-cmd/vendor-gems.rb

@@ -74,7 +74,7 @@ module Homebrew
                           "--no-document", "--no-wrappers", "--ignore-dependencies", "--force"
               (HOMEBREW_LIBRARY_PATH/"vendor/gems").cd do
                 source = Pathname.glob("#{gem}-*/").first
-                next if source.blank?
+                next unless source
 
                 # We cannot use `#ln_sf` here because that has unintended consequences when
                 # the symlink we want to create exists and points to an existing directory.

Library/Homebrew/development_tools.rb

@@ -28,7 +28,7 @@ class DevelopmentTools
 
     sig { returns(T::Boolean) }
     def installed?
-      locate("clang").present? || locate("gcc").present?
+      !!(locate("clang") || locate("gcc"))
     end
 
     sig { returns(String) }

Library/Homebrew/extend/blank.rb

@@ -56,4 +56,5 @@ require "extend/blank/hash"
 require "extend/blank/symbol"
 require "extend/blank/string"
 require "extend/blank/numeric"
+require "extend/blank/pathname"
 require "extend/blank/time"

Library/Homebrew/extend/blank/pathname.rb

@@ -0,0 +1,24 @@
+# typed: strict
+# frozen_string_literal: true
+
+class Pathname
+  # A Pathname is blank if its path is empty. Unlike `Pathname#empty?`,
+  # this never touches the filesystem, so an existing-but-empty file or
+  # directory is still present.
+  #
+  # ```ruby
+  # Pathname.new("").blank?     # => true
+  # Pathname.new(" ").blank?    # => false
+  # Pathname.new("test").blank? # => false
+  # ```
+  #
+  # @see https://github.com/rails/rails/blob/main/activesupport/lib/active_support/core_ext/pathname/blank.rb
+  #   `Pathname#blank?`
+  sig { returns(T::Boolean) }
+  def blank?
+    to_s.empty?
+  end
+
+  sig { returns(T::Boolean) }
+  def present? = !blank? # :nodoc:
+end

Library/Homebrew/formula.rb

@@ -499,7 +499,7 @@ class Formula
 
     return @unresolved_path if @unresolved_path.exist?
 
-    return local_bottle_path if local_bottle_path.presence&.exist?
+    return local_bottle_path if local_bottle_path&.exist?
 
     alias_path || @unresolved_path
   end
@@ -962,8 +962,6 @@ class Formula
   def linked_keg
     linked_keg = possible_names.map { |name| HOMEBREW_LINKED_KEGS/name }
                                .find(&:directory?)
-    # Truthiness, not `.present?`: `Pathname#present?` checks directory
-    # emptiness on disk, which is a wasted syscall here.
     linked_keg || (HOMEBREW_LINKED_KEGS/name)
   end
 

Library/Homebrew/formula_auditor.rb

@@ -666,7 +666,7 @@ module Homebrew
       return unless @new_formula
 
       # Using internal API here as using `Formulary.factory` is too slow
-      return if !@online && Homebrew::API::Internal.cached_packages_json_file_path.blank?
+      return if !@online && !Homebrew::API::Internal.cached_packages_json_file_path.exist?
 
       formula_url = formula.stable&.url
       return unless formula_url

Library/Homebrew/formula_installer.rb

@@ -268,7 +268,7 @@ class FormulaInstaller
       return false
     end
 
-    return true if formula.local_bottle_path.present?
+    return true if formula.local_bottle_path
 
     bottle = api_bottle || formula.bottle_for_tag(Utils::Bottles.tag)
     return false if bottle.nil?
@@ -1380,7 +1380,7 @@ on_request: installed_on_request?, options:)
 
     keg_formula_path = installed_prefix/".brew/#{formula.name}.rb"
     return keg_formula_path if formula.loaded_from_api?
-    return keg_formula_path if formula.local_bottle_path.present?
+    return keg_formula_path if formula.local_bottle_path
     return keg_formula_path if build_from_source?
 
     return keg_formula_path unless tap_formula_path.exist?
@@ -1470,7 +1470,7 @@ on_request: installed_on_request?, options:)
   sig { params(quiet: T::Boolean, enqueue: T::Boolean).void }
   def fetch_bottle_tab(quiet: false, enqueue: false)
     return if @fetch_bottle_tab
-    return if formula.local_bottle_path.present?
+    return if formula.local_bottle_path
 
     if (bottle = api_bottle || formula.bottle) &&
        (manifest_resource = bottle.github_packages_manifest_resource) &&
@@ -1500,7 +1500,7 @@ on_request: installed_on_request?, options:)
     fetch_dependencies
 
     return if only_deps?
-    return if formula.local_bottle_path.present?
+    return if formula.local_bottle_path
 
     downloadable_object = downloadable
     check_attestation = if pour_bottle?(output_warning: true)

Library/Homebrew/os.rb

@@ -124,7 +124,7 @@ module OS
     else
       "https://docs.brew.sh/Troubleshooting"
     end.freeze
-    PATH_OPEN = if wsl? && (wslview = which("wslview").presence)
+    PATH_OPEN = if wsl? && (wslview = which("wslview"))
       wslview.to_s
     else
       "xdg-open"

Library/Homebrew/services/cli.rb

@@ -146,7 +146,7 @@ module Homebrew
 
           install_service_file(service, file)
 
-          if file.blank? && verbose
+          if !file && verbose
             ohai "Generated service file for #{service.formula.name}:"
             puts "   #{service.dest.read.gsub("\n", "\n   ")}"
             puts
@@ -412,7 +412,7 @@ module Homebrew
         end
 
         temp = Tempfile.new(service.service_name)
-        temp << if file.blank?
+        temp << if file.nil?
           contents = service.service_file.read
 
           if sudo_service_user && System.launchctl?

Library/Homebrew/test/extend/blank/pathname_spec.rb

@@ -0,0 +1,50 @@
+# typed: true
+# frozen_string_literal: true
+
+require "extend/blank"
+
+# Modelled on ActiveSupport's `test/core_ext/pathname/blank_test.rb`.
+RSpec.describe Pathname do
+  let(:blank) { [described_class.new("")] }
+  let(:present) { [described_class.new(" "), described_class.new("."), described_class.new("test")] }
+
+  describe "#blank?" do
+    it "is blank if and only if the path string is empty" do
+      blank.each { |path| expect(path.blank?).to be(true), "#{path.inspect} should be blank" }
+      present.each { |path| expect(path.blank?).to be(false), "#{path.inspect} should not be blank" }
+    end
+  end
+
+  describe "#present?" do
+    it "is present if and only if the path string is not empty" do
+      blank.each { |path| expect(path.present?).to be(false), "#{path.inspect} should not be present" }
+      present.each { |path| expect(path.present?).to be(true), "#{path.inspect} should be present" }
+    end
+  end
+
+  describe "#presence" do
+    it "returns the pathname when present, otherwise nil" do
+      blank.each { |path| expect(path.presence).to be_nil }
+      present.each { |path| expect(path.presence).to be path }
+    end
+  end
+
+  describe "filesystem independence" do
+    # Before `Pathname#blank?` was redefined it dispatched to the filesystem
+    # via `Pathname#empty?`, so the empty path string was present and the
+    # existing empty file and directory were blank. A nonexistent path was
+    # present under both implementations.
+    it "judges by the path string, not filesystem content" do
+      expect(described_class.new("").blank?).to be true
+      expect(mktmpdir.present?).to be true
+      expect((mktmpdir/"nonexistent").present?).to be true
+    end
+
+    it "treats an existing empty file as present" do
+      file = mktmpdir/"empty-file"
+      FileUtils.touch file
+
+      expect(file.present?).to be true
+    end
+  end
+end

Library/Homebrew/test/formula_auditor_spec.rb

@@ -1997,7 +1997,7 @@ RSpec.describe Homebrew::FormulaAuditor do
     end
 
     specify "it warns if new formula uses the same URL as already existing package" do
-      fa = formula_auditor "duplicate-foo", <<~RUBY, new_formula: true, core_tap: true
+      fa = formula_auditor "duplicate-foo", <<~RUBY, new_formula: true, core_tap: true, online: true
         class DuplicateFoo < Formula
           url "https://brew.sh/foo-1.0.tgz"
         end
@@ -2010,7 +2010,7 @@ RSpec.describe Homebrew::FormulaAuditor do
     end
 
     specify "it does not warn about duplicates if formula is not new" do
-      fa = formula_auditor "duplicate-foo", <<~RUBY, new_formula: false, core_tap: true
+      fa = formula_auditor "duplicate-foo", <<~RUBY, new_formula: false, core_tap: true, online: true
         class DuplicateFoo < Formula
           url "https://brew.sh/foo-1.0.tgz"
         end
@@ -2020,6 +2020,20 @@ RSpec.describe Homebrew::FormulaAuditor do
 
       expect(fa.new_formula_problems).to be_empty
     end
+
+    specify "it skips the duplicate check offline when no packages data is cached" do
+      fa = formula_auditor "duplicate-foo", <<~RUBY, new_formula: true, core_tap: true, online: false
+        class DuplicateFoo < Formula
+          url "https://brew.sh/foo-1.0.tgz"
+        end
+      RUBY
+      allow(Homebrew::API::Internal).to receive(:cached_packages_json_file_path)
+        .and_return(Pathname("/nonexistent/packages.jws.json"))
+
+      fa.audit_duplicate_formula
+
+      expect(fa.new_formula_problems).to be_empty
+    end
   end
 
   describe "#audit_conflicts" do

Library/Homebrew/test/utils/tar_spec.rb

@@ -17,7 +17,7 @@ RSpec.describe Utils::Tar do
 
   describe ".available?" do
     it "returns true if tar or gnu-tar is available" do
-      if described_class.executable.present?
+      if described_class.executable
         expect(described_class).to be_available
       else
         expect(described_class).not_to be_available

Library/Homebrew/test_bot/test_formulae.rb

@@ -67,7 +67,8 @@ module Homebrew
 
         # If we have a cached event payload, then we failed to get the artifact we wanted
         # from `GITHUB_EVENT_PATH`, so use the cached payload to check for a SHA1.
-        event_payload = JSON.parse(T.must(cached_event_json).read) if cached_event_json.present?
+        cached_json = cached_event_json
+        event_payload = JSON.parse(cached_json.read) if cached_json
         event_payload ||= payload
 
         event_payload.fetch("before", nil)
@@ -236,7 +237,7 @@ module Homebrew
 
       sig { params(formula: String, bottle_dir: Pathname).returns(T.nilable(T::Hash[String, T.untyped])) }
       def local_bottle_hash(formula, bottle_dir:)
-        return if (local_bottle_json = bottle_glob(formula, bottle_dir, ".json").first).blank?
+        return unless (local_bottle_json = bottle_glob(formula, bottle_dir, ".json").first)
 
         JSON.parse(local_bottle_json.read)
       end

Library/Homebrew/utils/git.rb

@@ -213,7 +213,7 @@ module Utils
              to: T.nilable(String)).returns(Integer)
     }
     def self.count_coauthors(repository_path, person, from:, to:)
-      return 0 if repository_path.blank?
+      return 0 unless repository_path
 
       cmd = [git.to_s, "-C", repository_path.to_s, "log", "--oneline"]
       cmd << "--format='%(trailers:key=Co-authored-by:)''"

Library/Homebrew/utils/github/actions.rb

@@ -107,7 +107,7 @@ module GitHub
       # the `GITHUB_WORKSPACE` directory or if no `file` is specified.
       sig { returns(T::Boolean) }
       def relevant?
-        return true if @file.blank?
+        return true unless @file
 
         @file.descend.next.to_s != ".."
       end

Library/Homebrew/utils/tar.rb

@@ -15,7 +15,7 @@ module Utils
 
       sig { returns(T::Boolean) }
       def available?
-        executable.present?
+        !!executable
       end
 
       sig { returns(T.nilable(Pathname)) }