autoremove: don't remove formulae that were built from source

When a formula was built from source, it should not be removed by
`brew autoremove` as it will take a while to be installed again.

Fixes https://github.com/Homebrew/brew/issues/17433

Library/Homebrew/test/cmd/autoremove_spec.rb

@@ -11,13 +11,18 @@ RSpec.describe Homebrew::Cmd::Autoremove do
     let(:unused_formula) { Formula["testball2"] }
 
     before do
+      # Make testball1 poured from a bottle
       install_test_formula "testball1"
-      install_test_formula "testball2"
+      tab = Tab.for_name("testball1")
+      tab.poured_from_bottle = true
+      tab.write
 
-      # Make testball2 an unused dependency
+      # Make testball2 poured from a bottle and an unused dependency
+      install_test_formula "testball2"
       tab = Tab.for_name("testball2")
       tab.installed_on_request = false
       tab.installed_as_dependency = true
+      tab.poured_from_bottle = true
       tab.write
     end
 

Library/Homebrew/test/utils/autoremove_spec.rb

@@ -61,7 +61,7 @@ RSpec.describe Utils::Autoremove do
     end
   end
 
-  describe "::formulae_with_no_formula_dependents" do
+  describe "::bottled_formulae_with_no_formula_dependents" do
     include_context "with formulae for dependency testing"
 
     before do
@@ -72,17 +72,17 @@ RSpec.describe Utils::Autoremove 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))
+        expect(described_class.send(:bottled_formulae_with_no_formula_dependents, formulae))
           .to eq([formula_with_deps, formula_is_build_dep])
       end
     end
 
     context "when formulae are built from source" do
-      it "filters out runtime and build dependencies" do
+      it "filters out formulae" 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])
+        expect(described_class.send(:bottled_formulae_with_no_formula_dependents, formulae))
+          .to eq([])
       end
     end
   end

Library/Homebrew/utils/autoremove.rb

@@ -29,26 +29,31 @@ module Utils
              .flat_map { |f| [f, *f.runtime_formula_dependencies].compact }
       end
 
-      # An array of all installed {Formula} without runtime {Formula}
+      # An array of all installed bottled {Formula} without runtime {Formula}
       # dependents for bottles and without build {Formula} dependents
       # for those built from source.
       # @private
       sig { params(formulae: T::Array[Formula]).returns(T::Array[Formula]) }
-      def formulae_with_no_formula_dependents(formulae)
-        dependents = T.let([], T::Array[Formula])
+      def bottled_formulae_with_no_formula_dependents(formulae)
+        formulae_to_keep = T.let([], T::Array[Formula])
         formulae.each do |formula|
-          dependents += formula.runtime_formula_dependencies
+          formulae_to_keep += formula.runtime_formula_dependencies
 
-          # Ignore build dependencies when the formula is a bottle
-          next if formula.any_installed_keg&.tab&.poured_from_bottle
+          if (tab = formula.any_installed_keg&.tab)
+            # Ignore build dependencies when the formula is a bottle
+            next if tab.poured_from_bottle
+
+            # Keep the formula if it was built from source
+            formulae_to_keep << formula
+          end
 
           formula.deps.select(&:build?).each do |dep|
-            dependents << dep.to_formula
+            formulae_to_keep << dep.to_formula
           rescue FormulaUnavailableError
             # do nothing
           end
         end
-        formulae - dependents
+        formulae - formulae_to_keep
       end
 
       # Recursive function that returns an array of {Formula} without
@@ -56,7 +61,7 @@ module Utils
       # @private
       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|
+        unused_formulae = bottled_formulae_with_no_formula_dependents(formulae).reject do |f|
           f.any_installed_keg&.tab&.installed_on_request
         end