Document Tab.for_keg and use Keg#tab where possible.

Library/Homebrew/cleanup.rb

@@ -703,7 +703,7 @@ module Homebrew
 
       require "uninstall"
 
-      kegs_by_rack = removable_formulae.map(&:any_installed_keg).group_by(&:rack)
+      kegs_by_rack = removable_formulae.filter_map(&:any_installed_keg).group_by(&:rack)
       Uninstall.uninstall_kegs(kegs_by_rack)
 
       # The installed formula cache will be invalid after uninstalling.

Library/Homebrew/cli/named_args.rb

@@ -371,11 +371,11 @@ module Homebrew
         # Return keg if it is the only installed keg
         return kegs if kegs.length == 1
 
-        stable_kegs = kegs.reject { |k| k.version.head? }
+        stable_kegs = kegs.reject { |keg| keg.version.head? }
 
         if stable_kegs.blank?
           return kegs.max_by do |keg|
-            [Tab.for_keg(keg).source_modified_time, keg.version.revision]
+            [keg.tab.source_modified_time, keg.version.revision]
           end
         end
 

Library/Homebrew/cmd/info.rb

@@ -293,9 +293,9 @@ module Homebrew
         end
 
         kegs = formula.installed_kegs
-        heads, versioned = kegs.partition { |k| k.version.head? }
+        heads, versioned = kegs.partition { |keg| keg.version.head? }
         kegs = [
-          *heads.sort_by { |k| -Tab.for_keg(k).time.to_i },
+          *heads.sort_by { |keg| -keg.tab.time.to_i },
           *versioned.sort_by(&:scheme_and_version),
         ]
         if kegs.empty?
@@ -304,7 +304,7 @@ module Homebrew
           puts "Installed"
           kegs.each do |keg|
             puts "#{keg} (#{keg.abv})#{" *" if keg.linked?}"
-            tab = Tab.for_keg(keg).to_s
+            tab = keg.tab.to_s
             puts "  #{tab}" unless tab.empty?
           end
         end

Library/Homebrew/cmd/leaves.rb

@@ -40,11 +40,11 @@ module Homebrew
       private
 
       def installed_on_request?(formula)
-        Tab.for_keg(formula.any_installed_keg).installed_on_request
+        formula.any_installed_keg.tab.installed_on_request
       end
 
       def installed_as_dependency?(formula)
-        Tab.for_keg(formula.any_installed_keg).installed_as_dependency
+        formula.any_installed_keg.installed_as_dependency
       end
     end
   end

Library/Homebrew/cmd/update-report.rb

@@ -162,7 +162,7 @@ module Homebrew
               next unless formula.any_version_installed?
 
               keg = formula.installed_kegs.last
-              tab = Tab.for_keg(keg)
+              tab = keg.tab
               # force a `brew upgrade` from the linuxbrew-core version to the homebrew-core version (even if lower)
               tab.source["versions"]["version_scheme"] = -1
               tab.write
@@ -631,7 +631,7 @@ class Reporter
 
       next unless (dir = HOMEBREW_CELLAR/name).exist? # skip if formula is not installed.
 
-      tabs = dir.subdirs.map { |d| Tab.for_keg(Keg.new(d)) }
+      tabs = dir.subdirs.map { |d| Keg.new(d).tab }
       next if tabs.first.tap != tap # skip if installed formula is not from this tap.
 
       new_tap = Tap.fetch(new_tap_name)

Library/Homebrew/dev-cmd/bottle.rb

@@ -491,7 +491,7 @@ module Homebrew
             Tab.clear_cache
             Dependency.clear_cache
             Requirement.clear_cache
-            tab = Tab.for_keg(keg)
+            tab = keg.tab
             original_tab = tab.dup
             tab.poured_from_bottle = false
             tab.time = nil

Library/Homebrew/diagnostic.rb

@@ -832,7 +832,7 @@ module Homebrew
         kegs = Keg.all
 
         deleted_formulae = kegs.filter_map do |keg|
-          tap = Tab.for_keg(keg).tap
+          tap = keg.tab.tap
           tap_keg_name = tap ? "#{tap}/#{keg.name}" : keg.name
 
           loadable = [

Library/Homebrew/extend/os/linux/cmd/update-report.rb

@@ -23,7 +23,7 @@ module Homebrew
       next unless recursive_runtime_dependencies.map(&:name).include? "gcc"
 
       keg = formula.installed_kegs.last
-      tab = Tab.for_keg(keg)
+      tab = keg.tab
       # Force reinstallation upon `brew upgrade` to fix the bottle RPATH.
       tab.source["versions"]["version_scheme"] = -1
       tab.write

Library/Homebrew/extend/os/mac/formula_cellar_checks.rb

@@ -80,7 +80,7 @@ module FormulaCellarChecks
           #{checker.display_test_output}
       EOS
 
-      tab = Tab.for_keg(keg)
+      tab = keg.tab
       if tab.poured_from_bottle
         output += <<~EOS
           Rebuild this from source with:

Library/Homebrew/formula.rb

@@ -657,7 +657,7 @@ class Formula
     end
 
     head_versions.max_by do |pn_pkgversion|
-      [Tab.for_keg(prefix(pn_pkgversion)).source_modified_time, pn_pkgversion.revision]
+      [Keg.new(prefix(pn_pkgversion)).tab.source_modified_time, pn_pkgversion.revision]
     end
   end
 
@@ -751,6 +751,7 @@ class Formula
   end
 
   # All currently installed kegs.
+  sig { returns(T::Array[Keg]) }
   def installed_kegs
     installed_prefixes.map { |dir| Keg.new(dir) }
   end
@@ -1408,7 +1409,7 @@ class Formula
     rescue NotAKegError, Errno::ENOENT
       # file doesn't belong to any keg.
     else
-      tab_tap = Tab.for_keg(keg).tap
+      tab_tap = keg.tab.tap
       # this keg doesn't below to any core/tap formula, most likely coming from a DIY install.
       return false if tab_tap.nil?
 
@@ -1850,12 +1851,15 @@ class Formula
   # universal binaries in a {Formula}'s {Keg}.
   sig { params(targets: T.nilable(T.any(Pathname, String))).void }
   def deuniversalize_machos(*targets)
-    targets = nil if targets.blank?
+    if targets.none?
-    targets ||= any_installed_keg.mach_o_files.select do |file|
+      targets = any_installed_keg&.mach_o_files&.select do |file|
         file.arch == :universal && file.archs.include?(Hardware::CPU.arch)
       end
+    end
 
-    targets.each { |t| extract_macho_slice_from(Pathname.new(t), Hardware::CPU.arch) }
+    targets&.each do |target|
+      extract_macho_slice_from(Pathname(target), Hardware::CPU.arch)
+    end
   end
 
   sig { params(file: Pathname, arch: T.nilable(Symbol)).void }
@@ -2147,6 +2151,7 @@ class Formula
 
   # Returns a Keg for the opt_prefix or installed_prefix if they exist.
   # If not, return `nil`.
+  sig { returns(T.nilable(Keg)) }
   def any_installed_keg
     Formula.cache[:any_installed_keg] ||= {}
     Formula.cache[:any_installed_keg][full_name] ||= if (installed_prefix = any_installed_prefix)
@@ -2328,7 +2333,7 @@ class Formula
     hsh.merge!(dependencies_hash)
 
     hsh["installed"] = installed_kegs.sort_by(&:scheme_and_version).map do |keg|
-      tab = Tab.for_keg keg
+      tab = keg.tab
       {
         "version"                 => keg.version.to_s,
         "used_options"            => tab.used_options.as_flags,
@@ -2882,12 +2887,13 @@ class Formula
     eligible_for_cleanup = []
     if latest_version_installed?
       eligible_kegs = if head? && (head_prefix = latest_head_prefix)
-        head, stable = installed_kegs.partition { |k| k.version.head? }
+        head, stable = installed_kegs.partition { |keg| keg.version.head? }
-        # Remove newest head and stable kegs
+
-        head - [Keg.new(head_prefix)] + stable.sort_by(&:scheme_and_version).slice(0...-1)
+        # Remove newest head and stable kegs.
+        head - [Keg.new(head_prefix)] + T.must(stable.sort_by(&:scheme_and_version).slice(0...-1))
       else
         installed_kegs.select do |keg|
-          tab = Tab.for_keg(keg)
+          tab = keg.tab
           if version_scheme > tab.version_scheme
             true
           elsif version_scheme == tab.version_scheme

Library/Homebrew/formula_installer.rb

@@ -471,7 +471,7 @@ on_request: installed_on_request?, options:)
       Pathname(brew_prefix/"#{formula.name}.rb").atomic_write(s)
 
       keg = Keg.new(formula.prefix)
-      tab = Tab.for_keg(keg)
+      tab = keg.tab
       tab.installed_as_dependency = installed_as_dependency?
       tab.installed_on_request = installed_on_request?
       tab.write
@@ -707,7 +707,7 @@ on_request: installed_on_request?, options:)
 
     if df.linked_keg.directory?
       linked_keg = Keg.new(df.linked_keg.resolved_path)
-      tab = Tab.for_keg(linked_keg)
+      tab = linked_keg.tab
       keg_had_linked_keg = true
       keg_was_linked = linked_keg.linked?
       linked_keg.unlink
@@ -715,7 +715,7 @@ on_request: installed_on_request?, options:)
 
     if df.latest_version_installed?
       installed_keg = Keg.new(df.prefix)
-      tab ||= Tab.for_keg(installed_keg)
+      tab ||= installed_keg.tab
       tmp_keg = Pathname.new("#{installed_keg}.tmp")
       installed_keg.rename(tmp_keg)
     end
@@ -822,7 +822,7 @@ on_request: installed_on_request?, options:)
     end
 
     # Update tab with actual runtime dependencies
-    tab = Tab.for_keg(keg)
+    tab = keg.tab
     Tab.clear_cache
     f_runtime_deps = formula.runtime_dependencies(read_from_tab: false)
     tab.runtime_dependencies = Tab.runtime_deps_hash(formula, f_runtime_deps)

Library/Homebrew/formulary.rb

@@ -1038,7 +1038,7 @@ module Formulary
     force_bottle: T.unsafe(nil),
     flags: T.unsafe(nil)
   )
-    tab = Tab.for_keg(keg)
+    tab = keg.tab
     tap = tab.tap
     spec ||= tab.spec
 

Library/Homebrew/install.rb

@@ -211,7 +211,7 @@ module Homebrew
         return false unless formula.opt_prefix.directory?
 
         keg = Keg.new(formula.opt_prefix.resolved_path)
-        tab = Tab.for_keg(keg)
+        tab = keg.tab
         unless tab.installed_on_request
           tab.installed_on_request = true
           tab.write

Library/Homebrew/keg.rb

@@ -158,6 +158,7 @@ class Keg
                  :to_path, :hash, :abv, :disk_usage, :file_count, :directory?, :exist?, :/,
                  :join, :rename, :find
 
+  sig { params(path: Pathname).void }
   def initialize(path)
     path = path.resolved_path if path.to_s.start_with?("#{HOMEBREW_PREFIX}/opt/")
     raise "#{path} is not a valid keg" if path.parent.parent.realpath != HOMEBREW_CELLAR.realpath
@@ -508,6 +509,7 @@ class Keg
     end
   end
 
+  sig { returns(Tab) }
   def tab
     Tab.for_keg(self)
   end

Library/Homebrew/linkage_checker.rb

@@ -143,7 +143,7 @@ class LinkageChecker
         end
 
         begin
-          owner = Keg.for Pathname.new(dylib)
+          owner = Keg.for(Pathname(dylib))
         rescue NotAKegError
           @system_dylibs << dylib
         rescue Errno::ENOENT
@@ -159,7 +159,7 @@ class LinkageChecker
             @broken_dylibs << dylib
           end
         else
-          tap = Tab.for_keg(owner).tap
+          tap = owner.tab.tap
           f = if tap.nil? || tap.core_tap?
             owner.name
           else

Library/Homebrew/migrator.rb

@@ -128,7 +128,7 @@ class Migrator
     @old_cellar = HOMEBREW_CELLAR/oldname
     raise MigratorNoOldpathError, oldname unless old_cellar.exist?
 
-    @old_tabs = old_cellar.subdirs.map { |d| Tab.for_keg(Keg.new(d)) }
+    @old_tabs = old_cellar.subdirs.map { |d| Keg.new(d).tab }
     @old_tap = old_tabs.first.tap
 
     raise MigratorDifferentTapsError.new(formula, oldname, old_tap) if !force && !from_same_tap_user?
@@ -373,7 +373,7 @@ class Migrator
   # After migration every `INSTALL_RECEIPT.json` has the wrong path to the formula
   # so we must update `INSTALL_RECEIPT`s.
   def update_tabs
-    new_tabs = new_cellar.subdirs.map { |d| Tab.for_keg(Keg.new(d)) }
+    new_tabs = new_cellar.subdirs.map { |d| Keg.new(d).tab }
     new_tabs.each do |tab|
       tab.source["path"] = formula.path.to_s if tab.source["path"]
       tab.write

Library/Homebrew/reinstall.rb

@@ -25,7 +25,7 @@ module Homebrew
   )
     if formula.opt_prefix.directory?
       keg = Keg.new(formula.opt_prefix.resolved_path)
-      tab = Tab.for_keg(keg)
+      tab = keg.tab
       keg_had_linked_opt = true
       keg_was_linked = keg.linked?
       backup keg

Library/Homebrew/tab.rb

@@ -128,7 +128,11 @@ class Tab
     new(attributes)
   end
 
+  # Get the {Tab} for the given {Keg},
+  # or a fake one if the formula is not installed.
+  #
   # @api internal
+  sig { params(keg: T.any(Keg, Pathname)).returns(T.attached_class) }
   def self.for_keg(keg)
     path = keg/FILENAME
 

Library/Homebrew/test/formula_installer_bottle_spec.rb

@@ -34,7 +34,7 @@ RSpec.describe FormulaInstaller do
     expect(formula).to be_latest_version_installed
 
     begin
-      expect(Tab.for_keg(keg)).to be_poured_from_bottle
+      expect(keg.tab).to be_poured_from_bottle
 
       yield formula
     ensure

Library/Homebrew/test/formula_installer_spec.rb

@@ -30,7 +30,7 @@ RSpec.describe FormulaInstaller do
 
     begin
       Tab.clear_cache
-      expect(Tab.for_keg(keg)).not_to be_poured_from_bottle
+      expect(keg.tab).not_to be_poured_from_bottle
 
       yield formula if block_given?
     ensure

Library/Homebrew/test/installed_dependents_spec.rb

@@ -51,7 +51,7 @@ RSpec.describe InstalledDependents do
     end
 
     def alter_tab(keg)
-      tab = Tab.for_keg(keg)
+      tab = keg.tab
       yield tab
       tab.write
     end

Library/Homebrew/test/utils/autoremove_spec.rb

@@ -39,14 +39,25 @@ RSpec.describe Utils::Autoremove do
       ]
     end
 
-    let(:tab_from_keg) { double }
+    let(:tab_from_keg) { instance_double(Tab) }
 
     before do
-      allow(formula_with_deps).to receive(:runtime_formula_dependencies).and_return([first_formula_dep,
+      allow(formula_with_deps).to receive_messages(
-                                                                                     second_formula_dep])
+        runtime_formula_dependencies: [first_formula_dep, second_formula_dep],
-      allow(first_formula_dep).to receive(:runtime_formula_dependencies).and_return([second_formula_dep])
+        any_installed_keg:            instance_double(Keg, tab: tab_from_keg),
-
+      )
-      allow(Tab).to receive(:for_keg).and_return(tab_from_keg)
+      allow(first_formula_dep).to receive_messages(
+        runtime_formula_dependencies: [second_formula_dep],
+        any_installed_keg:            instance_double(Keg, tab: tab_from_keg),
+      )
+      allow(second_formula_dep).to receive_messages(
+        runtime_formula_dependencies: [],
+        any_installed_keg:            instance_double(Keg, tab: tab_from_keg),
+      )
+      allow(formula_is_build_dep).to receive_messages(
+        runtime_formula_dependencies: [],
+        any_installed_keg:            instance_double(Keg, tab: tab_from_keg),
+      )
     end
   end
 
@@ -60,6 +71,7 @@ RSpec.describe Utils::Autoremove do
     context "when formulae are bottles" do
       it "filters out runtime dependencies" do
         allow(tab_from_keg).to receive(:poured_from_bottle).and_return(true)
+
         expect(described_class.send(:formulae_with_no_formula_dependents, formulae))
           .to eq([formula_with_deps, formula_is_build_dep])
       end
@@ -68,6 +80,7 @@ RSpec.describe Utils::Autoremove do
     context "when formulae are built from source" do
       it "filters out runtime and build dependencies" do
         allow(tab_from_keg).to receive(:poured_from_bottle).and_return(false)
+
         expect(described_class.send(:formulae_with_no_formula_dependents, formulae))
           .to eq([formula_with_deps])
       end
@@ -83,12 +96,14 @@ RSpec.describe Utils::Autoremove do
 
     specify "installed on request" do
       allow(tab_from_keg).to receive(:installed_on_request).and_return(true)
+
       expect(described_class.send(:unused_formulae_with_no_formula_dependents, formulae))
         .to eq([])
     end
 
     specify "not installed on request" do
       allow(tab_from_keg).to receive(:installed_on_request).and_return(false)
+
       expect(described_class.send(:unused_formulae_with_no_formula_dependents, formulae))
         .to match_array(formulae)
     end

Library/Homebrew/upgrade.rb

@@ -161,7 +161,7 @@ module Homebrew
 
       if formula.opt_prefix.directory?
         keg = Keg.new(formula.opt_prefix.resolved_path)
-        tab = Tab.for_keg(keg)
+        tab = keg.tab
       end
 
       build_options = BuildOptions.new(Options.create(flags), formula.options)

Library/Homebrew/utils/autoremove.rb

@@ -40,7 +40,7 @@ module Utils
           dependents += formula.runtime_formula_dependencies
 
           # Ignore build dependencies when the formula is a bottle
-          next if Tab.for_keg(formula.any_installed_keg).poured_from_bottle
+          next if formula.any_installed_keg&.tab&.poured_from_bottle
 
           formula.deps.select(&:build?).each do |dep|
             dependents << dep.to_formula
@@ -57,7 +57,7 @@ module Utils
       sig { params(formulae: T::Array[Formula]).returns(T::Array[Formula]) }
       def unused_formulae_with_no_formula_dependents(formulae)
         unused_formulae = formulae_with_no_formula_dependents(formulae).reject do |f|
-          Tab.for_keg(f.any_installed_keg).installed_on_request
+          f.any_installed_keg&.tab&.installed_on_request
         end
 
         unless unused_formulae.empty?

Library/Homebrew/utils/bottles.rb

@@ -30,7 +30,7 @@ module Utils
       def built_as?(formula)
         return false unless formula.latest_version_installed?
 
-        tab = Tab.for_keg(formula.latest_installed_prefix)
+        tab = Keg.new(formula.latest_installed_prefix).tab
         tab.built_as_bottle
       end
 
@@ -117,7 +117,7 @@ module Utils
           tab_json = bottle_hash[formula.full_name]["bottle"]["tags"][tag]["tab"].to_json
           Tab.from_file_content(tab_json, tabfile)
         else
-          tab = Tab.for_keg(keg)
+          tab = keg.tab
 
           tab.runtime_dependencies = begin
             f_runtime_deps = formula.runtime_dependencies(read_from_tab: false)