brew/Library/Homebrew/test/formula_installer_spec.rb

# typed: false
# frozen_string_literal: true

require "formula"
require "formula_installer"
require "keg"
require "sandbox"
require "tab"
require "trust"
require "cmd/install"
require "test/support/fixtures/testball"
require "test/support/fixtures/testball_bottle"
require "test/support/fixtures/failball"
require "test/support/fixtures/failball_offline_install"

RSpec.describe FormulaInstaller do
  matcher :be_poured_from_bottle do
    match(&:poured_from_bottle)
  end

  def temporary_install(formula, **options)
    expect(formula).not_to be_latest_version_installed

    installer = FormulaInstaller.new(formula, **options)

    with_env(HOMEBREW_NO_INSTALL_FROM_API: "1") do
      installer.fetch
      installer.install
    end

    keg = Keg.new(formula.prefix)

    expect(formula).to be_latest_version_installed

    begin
      Tab.clear_cache
      expect(keg.tab).not_to be_poured_from_bottle

      yield formula if block_given?
    ensure
      Tab.clear_cache
      keg.unlink
      keg.uninstall
      formula.clear_cache
      # there will be log files when sandbox is enable.
      FileUtils.rm_r(formula.logs) if formula.logs.directory?
    end

    expect(keg).not_to exist
    expect(formula).not_to be_latest_version_installed
  end

  specify "basic installation" do
    temporary_install(Testball.new) do |f|
      # Test that things made it into the Keg
      # "readme" is empty, so it should not be installed
      expect(f.prefix/"readme").not_to exist

      expect(f.bin).to be_a_directory
      expect(f.bin.children.count).to eq(3)

      expect(f.libexec).to be_a_directory
      expect(f.libexec.children.count).to eq(1)

      expect(f.prefix/"main.c").not_to exist
      expect(f.prefix/"license").not_to exist

      # Test that things make it into the Cellar
      keg = Keg.new f.prefix
      keg.link

      bin = HOMEBREW_PREFIX/"bin"
      expect(bin).to be_a_directory
      expect(bin.children.count).to eq(3)
      expect(f.prefix/".brew/testball.rb").to be_readable
    end
  end

  specify "offline installation" do
    expect { temporary_install(FailballOfflineInstall.new) }.to raise_error(BuildError) if Sandbox.available?
  end

  specify "Formula is not poured from bottle when compiler specified" do
    temporary_install(TestballBottle.new, cc: "clang") do |f|
      tab = Tab.for_formula(f)
      expect(tab.compiler).to eq("clang")
    end
  end

  specify "relocated bottle install does not require developer tools on Apple Silicon", :needs_macos do
    formula = TestballBottle.new
    installer = described_class.new(formula)

    allow(installer).to receive_messages(lock: nil, pour_bottle?: true, quiet?: true)
    allow(Hardware::CPU).to receive(:arm?).and_return(true)
    allow(formula.bottle_specification).to receive(:skip_relocation?).and_return(false)
    expect(Homebrew::Diagnostic::Checks).not_to receive(:new)
    allow(installer).to receive(:check_conflicts).and_raise("stopped after preinstall checks")

    expect do
      installer.install
    end.to raise_error("stopped after preinstall checks")
  end

  describe "#finish" do
    it "runs structured post-install work through the post-install subprocess" do
      formula = formula "finish-install-steps" do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      installer = described_class.new(formula)
      tab = instance_double(Tab)
      keg = instance_double(Keg, tab:)

      allow(Keg).to receive(:new).with(formula.prefix).and_return(keg)
      allow(installer).to receive_messages(
        build_bottle?:               false,
        caveats:                     nil,
        debug_symbols?:              false,
        fix_dynamic_linkage:         nil,
        install_service:             nil,
        link:                        nil,
        link_manual_command_warning: nil,
        only_deps?:                  false,
        quiet?:                      true,
        show_summary_heading?:       false,
        skip_post_install?:          false,
        summary:                     "summary",
        verbose?:                    false,
      )
      allow(formula).to receive_messages(post_install_steps_defined?: true, post_install_defined?: false,
                                         runtime_dependencies: [])
      allow(CacheStoreDatabase).to receive(:use).with(:linkage)
      allow(Homebrew::EnvConfig).to receive(:sbom?).and_return(false)
      allow(Homebrew::Install).to receive(:global_post_install)
      allow(Tab).to receive_messages(clear_cache: nil, runtime_deps_hash: [])
      allow(tab).to receive(:runtime_dependencies=)
      allow(tab).to receive(:write)

      expect(formula).to receive(:install_etc_var).ordered
      expect(formula).not_to receive(:run_post_install_steps)
      expect(installer).to receive(:post_install).ordered

      installer.finish
    end
  end

  describe "#post_install" do
    it "restores bin/brew after a Landlock-sandboxed post-install replaces it" do
      prefix = mktmpdir
      stub_const("HOMEBREW_PREFIX", prefix)
      brew_file = prefix/"bin/brew"
      original_brew_file = prefix/"Homebrew/bin/brew"
      original_brew_file.dirname.mkpath
      original_brew_file.write "#!/bin/sh\n"
      brew_file.dirname.mkpath
      brew_file.make_relative_symlink original_brew_file
      original_target = brew_file.readlink
      original_directory_mode = brew_file.dirname.stat.mode & 07777
      formula = formula("replace-brew-postinstall") do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      installer = described_class.new(formula)
      sandbox = instance_double(Sandbox).as_null_object

      allow(installer).to receive_messages(post_install_formula_path: formula.path, use_sandbox?: true)
      allow(formula).to receive_messages(logs: mktmpdir, network_access_allowed?: true)
      allow(Sandbox).to receive_messages(full_write_isolation?: false, new: sandbox)
      allow(sandbox).to receive(:run) do
        FileUtils.rm_f brew_file
        brew_file.write "malicious\n"
        brew_file.dirname.chmod 0500
      end

      installer.post_install

      expect(brew_file).to be_a_symlink
      expect(brew_file.readlink).to eq(original_target)
      expect(brew_file.dirname.stat.mode & 07777).to eq(original_directory_mode)
    end
  end

  describe "#post_install_formula_path" do
    it "uses the API formula for structured-only post-installs" do
      formula = formula("api-install-steps") do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      installer = described_class.new(formula)

      allow(formula).to receive_messages(any_installed_prefix: mktmpdir, loaded_from_api?: true,
                                         post_install_defined?: false)

      expect(installer.post_install_formula_path).to eq(formula.full_name)
    end

    it "uses the keg formula for API post-installs with Ruby hooks" do
      formula = formula("api-post-install-hook") do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      installer = described_class.new(formula)
      installed_prefix = mktmpdir

      allow(formula).to receive_messages(any_installed_prefix: installed_prefix, loaded_from_api?: true,
                                         post_install_defined?: true)

      expect(installer.post_install_formula_path).to eq(installed_prefix/".brew/api-post-install-hook.rb")
    end
  end

  describe "#pour" do
    let(:f) do
      formula("missing-bottle-tab") do
        T.bind(self, T.class_of(Formula))
        url "https://brew.sh/missing-bottle-tab-1.0.tar.gz"

        bottle do
          sha256 cellar: :any_skip_relocation,
                 Utils::Bottles.tag.to_sym => "d7b9f4e8bf83608b71fe958a99f19f2e5e68bb2582965d32e41759c24f1aef97"
        end
      end
    end
    let(:installer) { Class.new(described_class).new(f) }
    let(:downloader) { instance_double(AbstractDownloadStrategy, basename: "missing-bottle-tab", stage: nil) }
    let(:downloadable) { instance_double(Resource, downloader:) }
    let(:tab) do
      instance_double(Tab, changed_files: nil, source: { "versions" => {} }, write: nil).as_null_object
    end
    let(:keg) { instance_double(Keg) }

    before do
      allow(installer).to receive(:downloadable).and_return(downloadable)
      allow(Utils::Bottles).to receive(:load_tab).with(f).and_return(tab)
      allow(Tab).to receive(:clear_cache)
      allow(Keg).to receive(:new).with(f.prefix).and_return(keg)
      allow(keg).to receive(:replace_placeholders_with_locations)
      allow(f.bottle_specification).to receive(:skip_relocation?).with(tab:).and_return(true)
    end

    it "preserves the skip-linkage decision for the default bottle domain" do
      expect(keg).to receive(:replace_placeholders_with_locations).with(nil, skip_linkage: true)

      installer.pour
    end

    it "relocates dynamic linkage without metadata from a bottle mirror" do
      ENV["HOMEBREW_BOTTLE_DOMAIN"] = "https://mirror.example.com"

      expect(keg).to receive(:replace_placeholders_with_locations).with(nil, skip_linkage: false)

      installer.pour
    end

    it "explains how a bottle mirror can provide metadata once per invocation" do
      ENV["HOMEBREW_BOTTLE_DOMAIN"] = "https://mirror.example.com"

      expect { 2.times { installer.pour } }
        .to output(satisfy do |stderr|
          stderr.scan("OCI registry proxy").one? &&
            stderr.include?("sh.brew.tab") && stderr.include?("HOMEBREW_ARTIFACT_DOMAIN")
        end).to_stderr
    end
  end

  describe "#build_bottle_postinstall" do
    let(:f) do
      formula "bottle-config" do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
    end
    let(:config_file) { HOMEBREW_PREFIX/"etc/bottle-config.conf" }

    before do
      FileUtils.rm_rf f.rack
      FileUtils.rm_f config_file
      FileUtils.rm_f Pathname("#{config_file}.default")
    end

    after do
      FileUtils.rm_rf f.rack
      FileUtils.rm_f config_file
      FileUtils.rm_f Pathname("#{config_file}.default")
    end

    it "stores new prefix config where install_etc_var restores it from" do
      installer = described_class.new(f)
      installer.build_bottle_preinstall
      config_file.dirname.mkpath
      config_file.write "new\n"

      installer.build_bottle_postinstall

      expect((f.bottle_prefix/"etc/bottle-config.conf").read).to eq("new\n")
    end
  end

  describe "#verify_deps_exist" do
    it "does not install an untapped dependency tap" do
      formula = Testball.new
      installer = described_class.new(formula)
      tap = instance_double(Tap, user: "user", repository: "repo", to_s: "user/repo", installed?: false)

      allow(installer).to receive(:compute_dependencies).and_raise(TapFormulaUnavailableError.new(tap, "foo"))

      expect(tap).not_to receive(:ensure_installed!)

      expect { installer.verify_deps_exist }
        .to raise_error(TapFormulaUnavailableError, /If you trust this tap/) { |error|
          expect(error.dependent).to eq(formula.full_name)
        }
    end
  end

  describe "#fetch_bottle_tab" do
    it "does not enqueue cached bottle manifests" do
      formula = formula("deno") do
        T.bind(self, T.class_of(Formula))
        url "https://brew.sh/deno-2.7.11.tar.gz"

        bottle do
          root_url HOMEBREW_BOTTLE_DEFAULT_DOMAIN
          sha256 cellar: :any_skip_relocation,
                 Utils::Bottles.tag.to_sym => "d7b9f4e8bf83608b71fe958a99f19f2e5e68bb2582965d32e41759c24f1aef97"
        end
      end
      installer = described_class.new(formula)
      installer.download_queue = instance_double(Homebrew::DownloadQueue)
      manifest_resource = formula.bottle&.github_packages_manifest_resource
      cached_download = manifest_resource&.cached_download

      allow(manifest_resource).to receive(:downloaded?).and_return(true)
      expect(manifest_resource).to receive(:verify_download_integrity).with(cached_download) do
        expect(Context.current.quiet?).to be(true)
      end
      expect(manifest_resource).not_to receive(:clear_cache)
      expect(installer.download_queue).not_to receive(:enqueue)

      installer.fetch_bottle_tab(enqueue: true)
    end

    it "enqueues invalid cached bottle manifests" do
      formula = formula("deno") do
        T.bind(self, T.class_of(Formula))
        url "https://brew.sh/deno-2.7.11.tar.gz"

        bottle do
          root_url HOMEBREW_BOTTLE_DEFAULT_DOMAIN
          sha256 cellar: :any_skip_relocation,
                 Utils::Bottles.tag.to_sym => "d7b9f4e8bf83608b71fe958a99f19f2e5e68bb2582965d32e41759c24f1aef97"
        end
      end
      installer = described_class.new(formula)
      installer.download_queue = instance_double(Homebrew::DownloadQueue)
      manifest_resource = formula.bottle&.github_packages_manifest_resource

      allow(manifest_resource).to receive(:downloaded?).and_return(true)
      manifest_resource&.manifest_annotations = {}
      expect(manifest_resource).to receive(:verify_download_integrity) do
        expect(Context.current.quiet?).to be(true)
        raise Resource::BottleManifest::Error
      end
      expect(installer.download_queue).to receive(:enqueue).with(manifest_resource)

      installer.fetch_bottle_tab(enqueue: true)

      # Read the raw ivar: the private memoising reader would re-parse the manifest.
      # rubocop:disable Homebrew/NoInstanceVariableAccessInTests
      expect(manifest_resource&.instance_variable_get(:@manifest_annotations)).to be_nil
      # rubocop:enable Homebrew/NoInstanceVariableAccessInTests
    end
  end

  describe "#enqueue_fetch" do
    let(:formula) { TestballBottle.new }
    let(:installer) { described_class.new(formula) }
    let(:download_queue) { instance_double(Homebrew::DownloadQueue) }
    let(:bottle) { instance_double(Bottle, cached_download: HOMEBREW_CACHE/"downloads/testball-bottle") }

    before do
      installer.download_queue = download_queue

      allow(Homebrew::EnvConfig).to receive(:verify_attestations?).and_return(false)
      allow(installer).to receive(:previously_fetched_formula)
      allow(installer).to receive(:pour_bottle?).with(output_warning: true).and_return(true)
      allow(installer).to receive(:downloadable).and_return(bottle)
      allow(installer).to receive(:fetch_bottle_tab)
    end

    it "starts a bottle download before enqueueing dependencies after the prelude" do
      installer.ran_prelude = true

      expect(download_queue).to receive(:enqueue)
        .with(bottle, check_attestation: false, stage: false).ordered
      expect(installer).to receive(:fetch_dependencies).ordered
      expect(download_queue).to receive(:enqueue)
        .with(bottle, check_attestation: false).ordered

      installer.enqueue_fetch
    end

    it "resolves dependencies before enqueueing a bottle without the prelude" do
      expect(installer).to receive(:fetch_dependencies).ordered
      expect(installer).to receive(:fetch_bottle_tab).with(enqueue: true).ordered
      expect(download_queue).to receive(:enqueue)
        .with(bottle, check_attestation: false).ordered

      installer.enqueue_fetch
    end

    it "does not requeue a bottle already enqueued by the prelude fetch" do
      allow(installer).to receive(:pour_bottle?).and_return(true)
      expect(download_queue).to receive(:enqueue)
        .with(bottle, check_attestation: false, stage: true).once
      installer.prelude_fetch

      expect(installer).to receive(:fetch_dependencies)

      installer.enqueue_fetch
    end
  end

  describe "linking defaults" do
    it "links non-keg-only formulae when link_keg is false" do
      ordinary_formula = formula "homebrew-link-default" do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end

      expect(described_class.new(ordinary_formula, link_keg: false).link_keg).to be true
    end

    it "links non-keg-only dependencies even when they were not previously linked" do
      dependency_formula = formula "homebrew-link-default-dependency" do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      dependency = instance_double(Dependency, to_formula: dependency_formula, name: dependency_formula.name,
                                               options: Options.new)
      installer = described_class.new(Testball.new)
      # Sorbet doesn't like `T.let(nil, T.nilable(described_class))`, but the
      # RuboCop will always autocorrect to that.
      # rubocop:disable RSpec/DescribedClass
      child_installer = T.let(nil, T.nilable(FormulaInstaller))
      # rubocop:enable RSpec/DescribedClass

      allow(dependency_formula).to receive_messages(
        linked_keg:                Pathname("/tmp/nonexistent-linked-keg"),
        latest_version_installed?: false,
        tap:                       nil,
        any_version_installed?:    false,
      )
      allow(installer).to receive(:oh1)
      allow(described_class).to receive(:new).and_wrap_original do |original, formula, **kwargs|
        instance = original.call(formula, **kwargs)
        next instance if formula != dependency_formula

        child_installer = instance
        allow(instance).to receive_messages(prelude: true, install: true, finish: true)
        instance
      end

      installer.install_dependency(dependency)

      expect(child_installer).not_to be_installed_on_request
      expect(child_installer&.link_keg).to be true
    end
  end

  describe "#check_conflicts" do
    let(:test_formula) do
      formula "testball" do
        T.bind(self, T.class_of(Formula))
        url "https://brew.sh/testball-0.1.tar.gz"
        conflicts_with "other"
      end
    end

    let(:conflicting_formula) do
      formula "other" do
        T.bind(self, T.class_of(Formula))
        url "https://brew.sh/other-0.1.tar.gz"
        conflicts_with "testball"
      end
    end

    before { allow(Formulary).to receive(:factory).with("other").and_return(conflicting_formula) }

    context "when conflicting formula is installed but not linked" do
      before do
        linked_keg = instance_double(Pathname, exist?: false)
        opt_prefix = instance_double(Pathname, exist?: true)
        allow(conflicting_formula).to receive_messages(linked_keg:, opt_prefix:)
      end

      it "does not raise an error" do
        installer = described_class.new(test_formula, link_keg: true)
        expect { installer.check_conflicts }.not_to raise_error
      end
    end

    context "when conflicting formula is installed" do
      before do
        linked_keg = opt_prefix = instance_double(Pathname, exist?: true)
        allow(conflicting_formula).to receive_messages(linked_keg:, opt_prefix:)
      end

      it "raises an error if linking keg" do
        installer = described_class.new(test_formula, link_keg: true)
        expect { installer.check_conflicts }.to raise_error(FormulaConflictError)
      end

      it "does not raise an error with force set" do
        installer = described_class.new(test_formula, link_keg: true, force: true)
        expect { installer.check_conflicts }.not_to raise_error
      end

      it "does not raise an error with skip_link set" do
        installer = described_class.new(test_formula, link_keg: true, skip_link: true)
        expect { installer.check_conflicts }.not_to raise_error
      end

      it "does not raise an error if not linking keg" do
        allow(test_formula).to receive(:keg_only?).and_return(true)
        installer = described_class.new(test_formula, link_keg: false, installed_on_request: false)
        expect { installer.check_conflicts }.not_to raise_error
      end
    end

    it "ignores conflicts that name the formula being installed" do
      f = formula("terraform", tap: Tap.fetch("thirdparty", "selfconflict")) do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
        conflicts_with "terraform"
      end

      expect(Formulary).not_to receive(:factory)

      described_class.new(f).check_conflicts
    ensure
      FileUtils.rm_rf HOMEBREW_TAP_DIRECTORY/"thirdparty"
    end
  end

  describe "#install_dependencies" do
    it "marks only outdated dependencies as upgradable in the header" do
      outdated = formula "outdated-dependency" do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      uninstalled = formula "uninstalled-dependency" do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      allow(outdated).to receive_messages(any_version_installed?: true, outdated?: true)
      allow(uninstalled).to receive_messages(any_version_installed?: false, outdated?: false)
      deps = [
        instance_double(Dependency, to_formula: outdated, name: outdated.name, to_s: outdated.name),
        instance_double(Dependency, to_formula: uninstalled, name: uninstalled.name, to_s: uninstalled.name),
      ]
      installer = described_class.new(Testball.new)
      allow(installer).to receive(:install_dependency)
      allow_any_instance_of(StringIO).to receive(:tty?).and_return(true)
      allow(Homebrew::EnvConfig).to receive(:no_emoji?).and_return(true)

      expect { installer.install_dependencies(deps) }
        .to output(/outdated-dependency.*\(upgradable\).*and.*uninstalled-dependency[^(]*$/m).to_stdout
    end

    it "does not render the first dependency name bolder than the rest" do
      ENV["HOMEBREW_COLOR"] = "1"
      dep_a = formula("dep-a") do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      dep_b = formula("dep-b") do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      [dep_a, dep_b].each { |f| allow(f).to receive_messages(any_version_installed?: true, outdated?: true) }
      deps = [
        instance_double(Dependency, to_formula: dep_a, name: dep_a.name, to_s: dep_a.name),
        instance_double(Dependency, to_formula: dep_b, name: dep_b.name, to_s: dep_b.name),
      ]
      installer = described_class.new(Testball.new)
      allow(installer).to receive(:install_dependency)
      allow_any_instance_of(StringIO).to receive(:tty?).and_return(true)

      expect { installer.install_dependencies(deps) }
        .to output(/:\e\[0m /).to_stdout
    end

    it "shows the formula header after installing a single dependency" do
      dep = formula("single-dep") do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      deps = [instance_double(Dependency, to_formula: dep, name: dep.name, to_s: dep.name)]
      installer = described_class.new(Testball.new)
      allow(installer).to receive(:install_dependency)

      installer.install_dependencies(deps)

      expect(installer.show_header?).to be(true)
    end
  end

  describe "#expand_dependencies_for_formula" do
    it "checks equal dependency satisfaction once per expansion" do
      shared_formula = instance_double(Formula, deps: [], name: "shared", full_name: "shared")
      shared_dep = Dependency.new("shared")
      repeated_shared_dep = Dependency.new("shared")
      expect(shared_dep).to receive(:satisfied?).once.and_return(false)
      expect(repeated_shared_dep).not_to receive(:satisfied?)
      allow(shared_dep).to receive(:to_formula).and_return(shared_formula)
      allow(repeated_shared_dep).to receive(:to_formula).and_return(shared_formula)

      first_parent = Dependency.new("first-parent")
      first_parent_formula = instance_double(Formula, deps: [shared_dep], name: "first-parent",
                                                     full_name: "first-parent")
      allow(first_parent).to receive_messages(satisfied?: false, to_formula: first_parent_formula)

      second_parent = Dependency.new("second-parent")
      second_parent_formula = instance_double(Formula, deps: [repeated_shared_dep], name: "second-parent",
                                                      full_name: "second-parent")
      allow(second_parent).to receive_messages(satisfied?: false, to_formula: second_parent_formula)

      f = formula "homebrew-expand-dependencies-cache" do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      allow(f).to receive(:deps).and_return([first_parent, second_parent])

      installer = described_class.new(f)
      build_options = BuildOptions.new(Options.new, Options.new)
      allow(installer).to receive_messages(effective_build_options_for: build_options, install_bottle_for?: false)

      deps = installer.expand_dependencies_for_formula(f)

      expect(deps.map(&:name)).to eq(%w[shared first-parent second-parent])
    end

    it "checks uses_from_macos dependencies with different bounds separately" do
      shared_formula = instance_double(Formula, deps: [], name: "shared", full_name: "shared")
      first_dep = UsesFromMacOSDependency.new("shared", [], bounds: { since: :ventura })
      second_dep = UsesFromMacOSDependency.new("shared", [], bounds: { since: :sonoma })
      expect(first_dep).to receive(:satisfied?).once.and_return(false)
      expect(second_dep).to receive(:satisfied?).once.and_return(false)
      allow(first_dep).to receive(:to_formula).and_return(shared_formula)
      allow(second_dep).to receive(:to_formula).and_return(shared_formula)

      first_parent = Dependency.new("first-parent")
      first_parent_formula = instance_double(Formula, deps: [first_dep], name: "first-parent",
                                                     full_name: "first-parent")
      allow(first_parent).to receive_messages(satisfied?: false, to_formula: first_parent_formula)

      second_parent = Dependency.new("second-parent")
      second_parent_formula = instance_double(Formula, deps: [second_dep], name: "second-parent",
                                                      full_name: "second-parent")
      allow(second_parent).to receive_messages(satisfied?: false, to_formula: second_parent_formula)

      f = formula "homebrew-expand-uses-from-macos-dependencies-cache" do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      allow(f).to receive(:deps).and_return([first_parent, second_parent])

      installer = described_class.new(f)
      build_options = BuildOptions.new(Options.new, Options.new)
      allow(installer).to receive_messages(effective_build_options_for: build_options, install_bottle_for?: false)

      deps = installer.expand_dependencies_for_formula(f)

      expect(deps.map(&:name)).to eq(%w[shared first-parent second-parent])
    end
  end

  describe "versioned keg-only linking defaults" do
    let(:base_name) { "homebrew-versioned-formula" }
    let(:formula_name) { "#{base_name}@1.0" }
    let(:keg_only_formula) do
      formula formula_name do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
        keg_only :versioned_formula
      end
    end

    before do
      allow(keg_only_formula).to receive_messages(any_version_installed?:  false,
                                                  link_overwrite_formulae: [])
    end

    it "does not link by default when it is not installed on request" do
      fi = described_class.new(keg_only_formula)

      expect(fi.link_keg).to be false
    end

    it "links by default when no sibling variants are installed" do
      fi = described_class.new(keg_only_formula, installed_on_request: true)

      expect(fi.link_keg).to be true
    end

    it "does not link by default when any version is already installed" do
      allow(keg_only_formula).to receive(:any_version_installed?).and_return(true)

      fi = described_class.new(keg_only_formula)

      expect(fi.link_keg).to be false
    end

    it "links when explicitly requested" do
      allow(keg_only_formula).to receive(:any_version_installed?).and_return(true)

      fi = described_class.new(keg_only_formula, link_keg: true)

      expect(fi.link_keg).to be true
    end

    it "does not link by default when another @-versioned formula is installed" do
      other_version = formula "#{base_name}@2.0" do
        T.bind(self, T.class_of(Formula))
        url "foo-2.0"
        keg_only :versioned_formula
      end
      allow(other_version).to receive(:any_version_installed?).and_return(true)
      allow(keg_only_formula).to receive(:link_overwrite_formulae).and_return([other_version])

      fi = described_class.new(keg_only_formula)

      expect(fi.link_keg).to be false
    end

    it "does not link by default when the unversioned sibling is installed" do
      unversioned_formula = formula base_name do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      allow(unversioned_formula).to receive(:any_version_installed?).and_return(true)
      allow(keg_only_formula).to receive(:link_overwrite_formulae).and_return([unversioned_formula])

      fi = described_class.new(keg_only_formula)

      expect(fi.link_keg).to be false
    end

    it "does not link by default when the unversioned sibling is keg-only" do
      unversioned_formula = formula base_name do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
        keg_only "some reason"
      end
      allow(keg_only_formula).to receive(:link_overwrite_formulae).and_return([unversioned_formula])

      fi = described_class.new(keg_only_formula)

      expect(fi.link_keg).to be false
    end

    it "does not link by default when the -full variant is installed" do
      full_variant = formula "#{base_name}-full" do
        T.bind(self, T.class_of(Formula))
        url "foo-full-1.0"
        keg_only :versioned_formula
      end
      allow(full_variant).to receive(:any_version_installed?).and_return(true)
      allow(keg_only_formula).to receive(:link_overwrite_formulae).and_return([full_variant])

      fi = described_class.new(keg_only_formula)

      expect(fi.link_keg).to be false
    end

    it "does not link by default when the non-full variant is installed" do
      full_formula = formula "#{base_name}-full" do
        T.bind(self, T.class_of(Formula))
        url "foo-full-1.0"
        keg_only :versioned_formula
      end
      non_full_variant = formula base_name do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
        keg_only :versioned_formula
      end
      allow(non_full_variant).to receive(:any_version_installed?).and_return(true)
      allow(full_formula).to receive_messages(any_version_installed?:  false,
                                              link_overwrite_formulae: [non_full_variant])

      fi = described_class.new(full_formula)

      expect(fi.link_keg).to be false
    end
  end

  describe "#link" do
    let(:versioned_formula) do
      formula "homebrew-versioned-formula@1.0" do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
        keg_only :versioned_formula
      end
    end
    let(:other_version) do
      formula "homebrew-versioned-formula" do
        T.bind(self, T.class_of(Formula))
        url "foo-2.0"
        keg_only :versioned_formula
      end
    end
    let(:keg) do
      instance_double(Keg, linked?: false)
    end

    before do
      allow(Formula).to receive(:clear_cache)
      allow(Cask::Caskroom).to receive(:path).and_return(Pathname("/tmp/nonexistent-caskroom"))
      allow(versioned_formula).to receive_messages(link_overwrite_formulae: [other_version],
                                                   any_version_installed?:  false)
      allow(other_version).to receive(:any_version_installed?).and_return(true)
    end

    it "only optlinks when default linking is disabled by an installed sibling" do
      installer = described_class.new(versioned_formula)

      expect(installer.link_keg).to be false
      expect(Homebrew::Unlink).not_to receive(:unlink_link_overwrite_formulae)
      expect(keg).to receive(:optlink).with(verbose: false, overwrite: false)
      expect(keg).not_to receive(:link)

      installer.link(keg)
    end

    it "unlinks siblings before linking when explicitly requested" do
      installer = described_class.new(versioned_formula, link_keg: true)

      expect(installer.link_keg).to be true
      expect(Homebrew::Unlink).to receive(:unlink_link_overwrite_formulae).with(versioned_formula,
                                                                                verbose: false).ordered
      expect(keg).to receive(:link).with(verbose: false, overwrite: false).ordered

      installer.link(keg)
    end
  end

  describe "#link_manual_command_warning" do
    let(:base_name) { "homebrew-versioned-formula" }
    let(:formula_name) { "#{base_name}@1.0" }
    let(:keg_only_formula) do
      formula formula_name do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
        keg_only :versioned_formula
      end
    end

    it "explains why a versioned formula was installed but not linked" do
      unversioned_formula = formula base_name do
        T.bind(self, T.class_of(Formula))
        url "foo-1.0"
      end
      allow(unversioned_formula).to receive_messages(any_version_installed?: true, linked?: true)
      allow(keg_only_formula).to receive_messages(any_version_installed?: false, linked?: false,
                                                  link_overwrite_formulae: [unversioned_formula])

      installer = described_class.new(keg_only_formula, installed_on_request: true)

      expect(installer.link_manual_command_warning).to eq <<~EOS
        #{formula_name} was installed but not linked because #{base_name} is already linked.
        To link this version, run:
          brew link #{formula_name}
      EOS
    end
  end

  describe "#check_install_sanity" do
    it "raises on direct cyclic dependency" do
      ENV["HOMEBREW_DEVELOPER"] = "1"

      dep_name = "homebrew-test-cyclic"
      dep_path = CoreTap.instance.new_formula_path(dep_name)
      dep_path.write <<~RUBY
        class #{Formulary.class_s(dep_name)} < Formula
          url "foo"
          version "0.1"
          depends_on "#{dep_name}"
        end
      RUBY
      f = Formulary.factory(dep_name)

      fi = described_class.new(f)

      expect do
        fi.check_install_sanity
      end.to raise_error(CannotInstallFormulaError)
    end

    it "raises on indirect cyclic dependency" do
      ENV["HOMEBREW_DEVELOPER"] = "1"

      formula1_name = "homebrew-test-formula1"
      formula2_name = "homebrew-test-formula2"
      formula1_path = CoreTap.instance.new_formula_path(formula1_name)
      formula1_path.write <<~RUBY
        class #{Formulary.class_s(formula1_name)} < Formula
          url "foo"
          version "0.1"
          depends_on "#{formula2_name}"
        end
      RUBY
      formula1 = Formulary.factory(formula1_name)

      formula2_path = CoreTap.instance.new_formula_path(formula2_name)
      formula2_path.write <<~RUBY
        class #{Formulary.class_s(formula2_name)} < Formula
          url "foo"
          version "0.1"
          depends_on "#{formula1_name}"
        end
      RUBY

      fi = described_class.new(formula1)

      expect do
        fi.check_install_sanity
      end.to raise_error(CannotInstallFormulaError)
    end

    it "raises on pinned dependency" do
      dep_name = "homebrew-test-dependency"
      dep_path = CoreTap.instance.new_formula_path(dep_name)
      dep_path.write <<~RUBY
        class #{Formulary.class_s(dep_name)} < Formula
          url "foo"
          version "0.2"
        end
      RUBY

      dependency = Formulary.factory(dep_name)

      dependent = formula do
        T.bind(self, T.class_of(Formula))
        url "foo"
        version "0.5"
        depends_on dependency.name.to_s
      end

      (dependency.prefix("0.1")/"bin"/"a").mkpath
      HOMEBREW_PINNED_KEGS.mkpath
      FileUtils.ln_s dependency.prefix("0.1"), HOMEBREW_PINNED_KEGS/dep_name

      dependency_keg = Keg.new(dependency.prefix("0.1"))
      dependency_keg.link

      expect(dependency_keg).to be_linked
      expect(dependency).to be_pinned

      fi = described_class.new(dependent)

      expect do
        fi.check_install_sanity
      end.to raise_error(CannotInstallFormulaError)
    end
  end

  describe "#forbidden_license_check" do
    it "raises on forbidden license on formula" do
      ENV["HOMEBREW_FORBIDDEN_LICENSES"] = "AGPL-3.0"

      f_name = "homebrew-forbidden-license"
      f_path = CoreTap.instance.new_formula_path(f_name)
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
          license "AGPL-3.0"
        end
      RUBY

      f = Formulary.factory(f_name)
      fi = described_class.new(f)

      expect do
        fi.forbidden_license_check
      end.to raise_error(CannotInstallFormulaError, /#{f_name}'s licenses are all forbidden/)
    end

    it "raises on forbidden license on formula with contact instructions" do
      ENV["HOMEBREW_FORBIDDEN_LICENSES"] = "AGPL-3.0"
      ENV["HOMEBREW_FORBIDDEN_OWNER"] = owner = "your dog"
      ENV["HOMEBREW_FORBIDDEN_OWNER_CONTACT"] = contact = "Woof loudly to get this unblocked."

      f_name = "homebrew-forbidden-license"
      f_path = CoreTap.instance.new_formula_path(f_name)
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
          license "AGPL-3.0"
        end
      RUBY

      f = Formulary.factory(f_name)
      fi = described_class.new(f)

      expect do
        fi.forbidden_license_check
      end.to raise_error(CannotInstallFormulaError, /#{owner}.+\n#{contact}/m)
    end

    it "raises on forbidden license on dependency" do
      ENV["HOMEBREW_FORBIDDEN_LICENSES"] = "GPL-3.0"

      dep_name = "homebrew-forbidden-dependency-license"
      dep_path = CoreTap.instance.new_formula_path(dep_name)
      dep_path.write <<~RUBY
        class #{Formulary.class_s(dep_name)} < Formula
          url "foo"
          version "0.1"
          license "GPL-3.0"
        end
      RUBY

      f_name = "homebrew-forbidden-dependent-license"
      f_path = CoreTap.instance.new_formula_path(f_name)
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
          depends_on "#{dep_name}"
        end
      RUBY

      f = Formulary.factory(f_name)
      fi = described_class.new(f)

      expect do
        fi.forbidden_license_check
      end.to raise_error(CannotInstallFormulaError, /dependency on #{dep_name} where all/)
    end

    it "raises on forbidden symbol license on formula" do
      ENV["HOMEBREW_FORBIDDEN_LICENSES"] = "public_domain"

      f_name = "homebrew-forbidden-license"
      f_path = CoreTap.instance.new_formula_path(f_name)
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
          license :public_domain
        end
      RUBY

      f = Formulary.factory(f_name)
      fi = described_class.new(f)

      expect do
        fi.forbidden_license_check
      end.to raise_error(CannotInstallFormulaError, /#{f_name}'s licenses are all forbidden/)
    end
  end

  describe "#forbidden_tap_check" do
    before do
      allow(Tap).to receive_messages(allowed_taps: allowed_taps_set, forbidden_taps: forbidden_taps_set)
      allow(Homebrew::Trust).to receive(:trusted_tap?).and_return(true)
    end

    let(:homebrew_forbidden) { Tap.fetch("homebrew/forbidden") }
    let(:allowed_third_party) { Tap.fetch("nothomebrew/allowed") }
    let(:disallowed_third_party) { Tap.fetch("nothomebrew/notallowed") }
    let(:allowed_taps_set) { [allowed_third_party.name] }
    let(:forbidden_taps_set) { [homebrew_forbidden.name] }

    it "raises on forbidden tap on formula" do
      f_tap = homebrew_forbidden
      f_name = "homebrew-forbidden-tap"
      f_path = homebrew_forbidden.new_formula_path(f_name)
      f_path.parent.mkpath
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
        end
      RUBY

      f = Formulary.factory("#{f_tap}/#{f_name}")
      fi = described_class.new(f)

      expect do
        fi.forbidden_tap_check
      end.to raise_error(CannotInstallFormulaError, /has the tap #{f_tap}/)
    ensure
      FileUtils.rm_r(f_path.parent.parent)
    end

    it "raises on not allowed third-party tap on formula" do
      f_tap = disallowed_third_party
      f_name = "homebrew-not-allowed-tap"
      f_path = disallowed_third_party.new_formula_path(f_name)
      f_path.parent.mkpath
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
        end
      RUBY

      f = Formulary.factory("#{f_tap}/#{f_name}")
      fi = described_class.new(f)

      expect do
        fi.forbidden_tap_check
      end.to raise_error(CannotInstallFormulaError, /has the tap #{f_tap}/)
    ensure
      FileUtils.rm_r(f_path.parent.parent.parent)
    end

    it "does not raise on allowed tap on formula" do
      f_tap = allowed_third_party
      f_name = "homebrew-allowed-tap"
      f_path = allowed_third_party.new_formula_path(f_name)
      f_path.parent.mkpath
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
        end
      RUBY

      f = Formulary.factory("#{f_tap}/#{f_name}")
      fi = described_class.new(f)

      expect { fi.forbidden_tap_check }.not_to raise_error
    ensure
      FileUtils.rm_r(f_path.parent.parent.parent)
    end

    it "raises on forbidden tap on dependency" do
      dep_tap = homebrew_forbidden
      dep_name = "homebrew-forbidden-dependency-tap"
      dep_path = homebrew_forbidden.new_formula_path(dep_name)
      dep_path.parent.mkpath
      dep_path.write <<~RUBY
        class #{Formulary.class_s(dep_name)} < Formula
          url "foo"
          version "0.1"
        end
      RUBY

      f_name = "homebrew-forbidden-dependent-tap"
      f_path = CoreTap.instance.new_formula_path(f_name)
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
          depends_on "#{dep_name}"
        end
      RUBY

      f = Formulary.factory(f_name)
      fi = described_class.new(f)

      expect do
        fi.forbidden_tap_check
      end.to raise_error(CannotInstallFormulaError, /from the #{dep_tap} tap but/)
    ensure
      FileUtils.rm_r(dep_path.parent.parent)
    end
  end

  describe "#forbidden_formula_check" do
    it "raises on forbidden formula" do
      ENV["HOMEBREW_FORBIDDEN_FORMULAE"] = f_name = "homebrew-forbidden-formula"
      f_path = CoreTap.instance.new_formula_path(f_name)
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
        end
      RUBY

      f = Formulary.factory(f_name)
      fi = described_class.new(f)

      expect do
        fi.forbidden_formula_check
      end.to raise_error(CannotInstallFormulaError, /#{f_name} was forbidden/)
    end

    it "raises on forbidden dependency" do
      ENV["HOMEBREW_FORBIDDEN_FORMULAE"] = dep_name = "homebrew-forbidden-dependency-formula"
      dep_path = CoreTap.instance.new_formula_path(dep_name)
      dep_path.write <<~RUBY
        class #{Formulary.class_s(dep_name)} < Formula
          url "foo"
          version "0.1"
        end
      RUBY

      f_name = "homebrew-forbidden-dependent-formula"
      f_path = CoreTap.instance.new_formula_path(f_name)
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
          depends_on "#{dep_name}"
        end
      RUBY

      f = Formulary.factory(f_name)
      fi = described_class.new(f)

      expect do
        fi.forbidden_formula_check
      end.to raise_error(CannotInstallFormulaError, /#{dep_name} formula was forbidden/)
    end
  end

  describe "#prelude_fetch" do
    context "with an API-loaded bottled formula" do
      let(:deno_formula) do
        formula("deno") do
          T.bind(self, T.class_of(Formula))
          url "https://brew.sh/deno-2.7.11.tar.gz"
        end
      end
      let(:formula_struct) do
        Homebrew::API::FormulaStruct.new(
          bottle_checksums:     [
            {
              cellar:                  :any_skip_relocation,
              Utils::Bottles.tag.to_sym => "d7b9f4e8bf83608b71fe958a99f19f2e5e68bb2582965d32e41759c24f1aef97",
            },
          ],
          bottle_present:       true,
          desc:                 "deno",
          homepage:             "https://brew.sh",
          license:              "MIT",
          ruby_source_checksum: "abc123",
          stable_present:       true,
          stable_version:       "2.7.11",
        )
      end
      let(:installer) do
        installer = described_class.new(deno_formula, ignore_deps: true)
        installer.download_queue = instance_double(Homebrew::DownloadQueue)
        installer
      end

      before do
        allow(deno_formula).to receive_messages(
          bottle_tag?:               true,
          core_formula?:             true,
          loaded_from_internal_api?: true,
          pour_bottle?:              true,
        )
        allow(Homebrew::API::Internal).to receive(:formula_struct).with("deno").and_return(formula_struct)
      end

      it "uses API bottle metadata to enqueue the manifest and bottle" do
        expect(deno_formula).not_to receive(:bottle_for_tag)
        expect(deno_formula).not_to receive(:bottle)
        expect(installer.download_queue).to receive(:enqueue).with(an_instance_of(Resource::BottleManifest))
        expect(installer.download_queue).to receive(:enqueue)
          .with(an_instance_of(Bottle), check_attestation: false, stage: true)

        installer.prelude_fetch
      end

      it "enqueues only the bottle manifest when fetching metadata" do
        expect(installer.download_queue).to receive(:enqueue).with(an_instance_of(Resource::BottleManifest))

        installer.prelude_fetch(metadata_only: true)
      end

      it "enqueues the bottle without repeating metadata work after a metadata-only run" do
        expect(installer.download_queue).to receive(:enqueue).with(an_instance_of(Resource::BottleManifest)).once

        installer.prelude_fetch(metadata_only: true)

        expect(installer.download_queue).to receive(:enqueue)
          .with(an_instance_of(Bottle), check_attestation: false, stage: true)

        installer.prelude_fetch
      end
    end

    it "does not repeat source download prelude work" do
      f = formula("homebrew-prelude-fetch-once") do
        T.bind(self, T.class_of(Formula))
        url "https://brew.sh/prelude-fetch-once-0.1.tar.gz"
      end
      allow(f).to receive(:loaded_from_api?).and_return(true)
      fi = described_class.new(f, ignore_deps: true)
      fi.download_queue = instance_double(Homebrew::DownloadQueue)

      expect(Homebrew::API::Formula).to receive(:source_download)
        .with(f, download_queue: fi.download_queue, enqueue: true)
        .once

      fi.prelude_fetch
      fi.prelude_fetch
    end

    it "raises on forbidden formula tap before fetching the source from the API" do
      homebrew_forbidden = Tap.fetch("homebrew/forbidden")
      allow(Tap).to receive_messages(allowed_taps: [], forbidden_taps: [homebrew_forbidden.name])
      f_name = "homebrew-forbidden-fail-fast-tap"
      f_path = homebrew_forbidden.new_formula_path(f_name)
      f_path.parent.mkpath
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
        end
      RUBY

      f = Formulary.factory("#{homebrew_forbidden}/#{f_name}")
      allow(f).to receive(:loaded_from_api?).and_return(true)
      fi = described_class.new(f)

      expect(Homebrew::API::Formula).not_to receive(:source_download)

      expect { fi.prelude_fetch }.to raise_error(CannotInstallFormulaError, /has the tap #{homebrew_forbidden}/)
    ensure
      FileUtils.rm_r(f_path.parent.parent)
    end

    it "raises on forbidden formula before fetching the source from the API" do
      ENV["HOMEBREW_FORBIDDEN_FORMULAE"] = f_name = "homebrew-forbidden-fail-fast-formula"
      f_path = CoreTap.instance.new_formula_path(f_name)
      f_path.write <<~RUBY
        class #{Formulary.class_s(f_name)} < Formula
          url "foo"
          version "0.1"
        end
      RUBY

      f = Formulary.factory(f_name)
      allow(f).to receive(:loaded_from_api?).and_return(true)
      fi = described_class.new(f)

      expect(Homebrew::API::Formula).not_to receive(:source_download)

      expect { fi.prelude_fetch }.to raise_error(CannotInstallFormulaError, /was forbidden/)
    end
  end

  specify "install fails with BuildError when a system() call fails" do
    ENV["HOMEBREW_TEST_NO_EXIT_CLEANUP"] = "1"
    ENV["FAILBALL_BUILD_ERROR"] = "1"

    expect do
      temporary_install(Failball.new)
    end.to raise_error(BuildError)
  end

  specify "install fails with a RuntimeError when #install raises" do
    ENV["HOMEBREW_TEST_NO_EXIT_CLEANUP"] = "1"

    expect do
      temporary_install(Failball.new)
    end.to raise_error(RuntimeError)
  end

  describe "#caveats" do
    subject(:formula_installer) { described_class.new(Testball.new) }

    it "shows audit problems if HOMEBREW_DEVELOPER is set" do
      ENV["HOMEBREW_DEVELOPER"] = "1"
      with_env(HOMEBREW_NO_INSTALL_FROM_API: "1") do
        formula_installer.fetch
        formula_installer.install
      end
      expect(formula_installer).to receive(:audit_installed).and_call_original
      formula_installer.caveats
    end
  end

  describe "#install_service" do
    it "works if service is set" do
      formula = Testball.new
      service = Homebrew::Service.new(formula)
      launchd_service_path = formula.launchd_service_path
      service_path = formula.systemd_service_path
      formula.opt_prefix.mkpath

      expect(formula).to receive(:service?).and_return(true)
      expect(formula).to receive(:service).at_least(:once).and_return(service)
      expect(formula).to receive(:launchd_service_path).and_call_original
      expect(formula).to receive(:systemd_service_path).and_call_original

      expect(service).to receive(:timed?).and_return(false)
      expect(service).to receive(:command?).and_return(true)
      expect(service).to receive(:to_plist).and_return("plist")
      expect(service).to receive(:to_systemd_unit).and_return("unit")

      installer = described_class.new(formula)
      expect do
        installer.install_service
      end.not_to output(/Error: Failed to install service files/).to_stderr

      expect(launchd_service_path).to exist
      expect(service_path).to exist
    end

    it "works if timed service is set" do
      formula = Testball.new
      service = Homebrew::Service.new(formula)
      launchd_service_path = formula.launchd_service_path
      service_path = formula.systemd_service_path
      timer_path = formula.systemd_timer_path
      formula.opt_prefix.mkpath

      expect(formula).to receive(:service?).and_return(true)
      expect(formula).to receive(:service).at_least(:once).and_return(service)
      expect(formula).to receive(:launchd_service_path).and_call_original
      expect(formula).to receive(:systemd_service_path).and_call_original
      expect(formula).to receive(:systemd_timer_path).and_call_original

      expect(service).to receive(:timed?).and_return(true)
      expect(service).to receive(:command?).and_return(true)
      expect(service).to receive(:to_plist).and_return("plist")
      expect(service).to receive(:to_systemd_unit).and_return("unit")
      expect(service).to receive(:to_systemd_timer).and_return("timer")

      installer = described_class.new(formula)
      expect do
        installer.install_service
      end.not_to output(/Error: Failed to install service files/).to_stderr

      expect(launchd_service_path).to exist
      expect(service_path).to exist
      expect(timer_path).to exist
    end

    it "returns without definition" do
      formula = Testball.new
      path = formula.launchd_service_path
      formula.opt_prefix.mkpath

      expect(formula).to receive(:service?).and_return(nil)
      expect(formula).not_to receive(:launchd_service_path)

      installer = described_class.new(formula)
      expect do
        installer.install_service
      end.not_to output(/Error: Failed to install service files/).to_stderr

      expect(path).not_to exist
    end
  end

  describe "#build" do
    it "attempts source download when formula is loaded from API" do
      formula = Testball.new
      allow(formula).to receive(:loaded_from_api?).and_return(true)

      source_formula = Testball.new
      allow(source_formula).to receive(:loaded_from_api?).and_return(false)

      expect(Homebrew::API::Formula).to receive(:source_download_formula)
        .with(formula)
        .and_return(source_formula)

      installer = described_class.new(formula)

      # Stub out the actual build subprocess since we only care about the guard
      allow(installer).to receive(:build_argv).and_return([])
      allow(Utils).to receive(:safe_fork)
      allow(source_formula).to receive_messages(logs: mktmpdir, update_head_version: nil, prefix: mktmpdir,
                                                network_access_allowed?: true)
      allow(Keg).to receive(:new).and_return(instance_double(Keg, empty_installation?: false))

      installer.build

      expect(installer.formula).to eq(source_formula)
    end

    it "raises when formula is loaded from API and source download fails" do
      formula = Testball.new
      allow(formula).to receive(:loaded_from_api?).and_return(true)

      expect(Homebrew::API::Formula).to receive(:source_download_formula)
        .with(formula)
        .and_raise(CannotInstallFormulaError, "source code not found")

      installer = described_class.new(formula)

      expect do
        installer.build
      end.to raise_error(CannotInstallFormulaError, /source code not found/)
    end

    it "exposes local formula and trust paths to the sandbox" do
      formula_path = mktmpdir/"homebrew-local-formula.rb"
      FileUtils.touch formula_path
      formula = formula("homebrew-local-formula", path: formula_path) do
        T.bind(self, T.class_of(Formula))
        url "foo"
        version "1.0"
      end
      installer = described_class.new(formula)
      sandbox = instance_double(Sandbox)

      allow(installer).to receive(:build_argv).and_return([])
      allow(Sandbox).to receive_messages(available?: true, new: sandbox)
      allow(sandbox).to receive_messages(record_log: nil, allow_read_if_exists: nil, allow_write_temp_and_cache: nil,
                                         allow_write_log: nil, allow_cvs: nil, allow_fossil: nil,
                                         allow_write_xcode: nil, allow_write_cellar: nil, deny_read_home: nil,
                                         run: nil)
      allow(formula).to receive_messages(logs: mktmpdir, update_head_version: nil, prefix: mktmpdir,
                                         network_access_allowed?: true)
      allow(Keg).to receive(:new).and_return(instance_double(Keg, empty_installation?: false))

      expect(sandbox).to receive(:allow_read_if_exists).with(path: formula_path).ordered
      expect(sandbox).to receive(:allow_read_if_exists).with(path: Homebrew::Trust.trust_file).ordered

      with_env(HOMEBREW_REQUIRE_TAP_TRUST: "1") do
        installer.build
      end
    end
  end
end