# coding: US-ASCII

require_relative "helper"
require "rubygems"
require "rubygems/command"
require "rubygems/installer"
require "pathname"
require "tmpdir"
require "rbconfig"

class TestGem < Gem::TestCase
  PLUGINS_LOADED = [] # rubocop:disable Style/MutableConstant

  PROJECT_DIR = File.expand_path("../..", __dir__)

  def setup
    super

    PLUGINS_LOADED.clear

    common_installer_setup

    @additional = %w[a b].map {|d| File.join @tempdir, d }
  end

  def test_self_finish_resolve
    a1 = util_spec "a", "1", "b" => "> 0"
    b1 = util_spec "b", "1", "c" => ">= 1"
    b2 = util_spec "b", "2", "c" => ">= 2"
    c1 = util_spec "c", "1"
    c2 = util_spec "c", "2"

    install_specs c1, c2, b1, b2, a1

    a1.activate

    assert_equal %w[a-1], loaded_spec_names
    assert_equal ["b (> 0)"], unresolved_names

    Gem.finish_resolve

    assert_equal %w[a-1 b-2 c-2], loaded_spec_names
    assert_equal [], unresolved_names
  end

  def test_self_finish_resolve_wtf
    a1 = util_spec "a", "1", "b" => "> 0", "d" => "> 0"    # this
    b1 = util_spec "b", "1", { "c" => ">= 1" }, "lib/b.rb" # this
    b2 = util_spec "b", "2", { "c" => ">= 2" }, "lib/b.rb"
    c1 = util_spec "c", "1"                                # this
    c2 = util_spec "c", "2"
    d1 = util_spec "d", "1", { "c" => "< 2" },  "lib/d.rb"
    d2 = util_spec "d", "2", { "c" => "< 2" },  "lib/d.rb" # this

    install_specs c1, c2, b1, b2, d1, d2, a1

    a1.activate

    assert_equal %w[a-1], loaded_spec_names
    assert_equal ["b (> 0)", "d (> 0)"], unresolved_names

    Gem.finish_resolve

    assert_equal %w[a-1 b-1 c-1 d-2], loaded_spec_names
    assert_equal [], unresolved_names
  end

  def test_self_finish_resolve_respects_loaded_specs
    a1 = util_spec "a", "1", "b" => "> 0"
    b1 = util_spec "b", "1", "c" => ">= 1"
    b2 = util_spec "b", "2", "c" => ">= 2"
    c1 = util_spec "c", "1"
    c2 = util_spec "c", "2"

    install_specs c1, c2, b1, b2, a1

    a1.activate
    c1.activate

    assert_equal %w[a-1 c-1], loaded_spec_names
    assert_equal ["b (> 0)"], unresolved_names

    Gem.finish_resolve

    assert_equal %w[a-1 b-1 c-1], loaded_spec_names
    assert_equal [], unresolved_names
  end

  def test_self_install
    spec_fetcher do |f|
      f.gem  "a", 1
      f.spec "a", 2
    end

    gemhome2 = "#{@gemhome}2"

    installed = Gem.install "a", "= 1", install_dir: gemhome2

    assert_equal %w[a-1], installed.map(&:full_name)

    assert_path_exist File.join(gemhome2, "gems", "a-1")
  end

  def test_self_install_in_rescue
    spec_fetcher do |f|
      f.gem  "a", 1
      f.spec "a", 2
    end

    gemhome2 = "#{@gemhome}2"

    installed =
      begin
        raise "Error"
      rescue StandardError
        Gem.install "a", "= 1", install_dir: gemhome2
      end
    assert_equal %w[a-1], installed.map(&:full_name)
  end

  def test_self_install_permissions
    assert_self_install_permissions
  end

  def test_self_install_permissions_umask_0
    umask = File.umask(0)
    assert_self_install_permissions
  ensure
    File.umask(umask)
  end

  def test_self_install_permissions_umask_077
    umask = File.umask(0o077)
    assert_self_install_permissions(data_mode: 0o600)
  ensure
    File.umask(umask)
  end

  def test_self_install_permissions_with_format_executable
    assert_self_install_permissions(format_executable: true)
  end

  def test_self_install_permissions_with_format_executable_and_non_standard_ruby_install_name
    Gem::Installer.exec_format = nil
    ruby_install_name "ruby27" do
      assert_self_install_permissions(format_executable: true)
    end
  ensure
    Gem::Installer.exec_format = nil
  end

  def assert_self_install_permissions(format_executable: false, data_mode: 0o640)
    mask = Gem.win_platform? ? 0o700 : 0o777
    options = {
      dir_mode: 0o500,
      prog_mode: Gem.win_platform? ? 0o410 : 0o510,
      data_mode: data_mode,
      wrappers: true,
      format_executable: format_executable,
    }
    Dir.chdir @tempdir do
      Dir.mkdir "bin"
      Dir.mkdir "data"

      File.write "bin/foo", "#!/usr/bin/env ruby\n"
      File.chmod 0o755, "bin/foo"

      File.write "data/foo.txt", "blah\n"

      spec_fetcher do |f|
        f.gem "foo", 1 do |s|
          s.executables = ["foo"]
          s.files = %w[bin/foo data/foo.txt]
        end
      end
      Gem.install "foo", Gem::Requirement.default, options
    end

    prog_mode = (options[:prog_mode] & mask).to_s(8)
    dir_mode = (options[:dir_mode] & mask).to_s(8)
    data_mode = (options[:data_mode] & mask).to_s(8)
    prog_name = "foo"
    prog_name = RbConfig::CONFIG["ruby_install_name"].sub("ruby", "foo") if options[:format_executable]
    expected = {
      "bin/#{prog_name}" => prog_mode,
      "gems/foo-1" => dir_mode,
      "gems/foo-1/bin" => dir_mode,
      "gems/foo-1/data" => dir_mode,
      "gems/foo-1/bin/foo" => prog_mode,
      "gems/foo-1/data/foo.txt" => data_mode,
    }
    # add Windows script
    expected["bin/#{prog_name}.bat"] = mask.to_s(8) if Gem.win_platform?
    result = {}
    Dir.chdir @gemhome do
      expected.each_key do |n|
        result[n] = (File.stat(n).mode & mask).to_s(8)
      end
    end
    assert_equal(expected, result)
  ensure
    File.chmod(0o755, *Dir.glob(@gemhome + "/gems/**/"))
  end

  def test_require_missing
    assert_raise ::LoadError do
      require "test_require_missing"
    end
  end

  def test_require_does_not_glob
    a1 = util_spec "a", "1", nil, "lib/a1.rb"

    install_specs a1

    assert_raise ::LoadError do
      require "a*"
    end

    assert_equal [], loaded_spec_names
  end

  def test_self_bin_path_active
    a1 = util_spec "a", "1" do |s|
      s.executables = ["exec"]
    end

    util_spec "a", "2" do |s|
      s.executables = ["exec"]
    end

    a1.activate

    assert_match "a-1/bin/exec", Gem.bin_path("a", "exec", ">= 0")
  end

  def test_self_bin_path_picking_newest
    a1 = util_spec "a", "1" do |s|
      s.executables = ["exec"]
    end

    a2 = util_spec "a", "2" do |s|
      s.executables = ["exec"]
    end

    install_specs a1, a2

    assert_match "a-2/bin/exec", Gem.bin_path("a", "exec", ">= 0")
  end

  def test_self_activate_bin_path_no_exec_name
    e = assert_raise ArgumentError do
      Gem.activate_bin_path "a"
    end

    assert_equal "you must supply exec_name", e.message
  end

  def test_activate_bin_path_resolves_eagerly
    a1 = util_spec "a", "1" do |s|
      s.executables = ["exec"]
      s.add_dependency "b"
    end

    b1 = util_spec "b", "1" do |s|
      s.add_dependency "c", "2"
    end

    b2 = util_spec "b", "2" do |s|
      s.add_dependency "c", "1"
    end

    c1 = util_spec "c", "1"
    c2 = util_spec "c", "2"

    install_specs c1, c2, b1, b2, a1

    Gem.activate_bin_path("a", "exec", ">= 0")

    # If we didn't eagerly resolve, this would activate c-2 and then the
    # finish_resolve would cause a conflict
    gem "c"
    Gem.finish_resolve

    assert_equal %w[a-1 b-2 c-1], loaded_spec_names
  end

  def test_activate_bin_path_does_not_error_if_a_gem_thats_not_finally_activated_has_orphaned_dependencies
    a1 = util_spec "a", "1" do |s|
      s.executables = ["exec"]
      s.add_dependency "b"
    end

    b1 = util_spec "b", "1" do |s|
      s.add_dependency "c", "1"
    end

    b2 = util_spec "b", "2" do |s|
      s.add_dependency "c", "2"
    end

    c2 = util_spec "c", "2"

    install_specs c2, b1, b2, a1

    # c1 is missing, but not needed for activation, so we should not get any errors here

    Gem.activate_bin_path("a", "exec", ">= 0")

    assert_equal %w[a-1 b-2 c-2], loaded_spec_names
  end

  def test_activate_bin_path_raises_a_meaningful_error_if_a_gem_thats_finally_activated_has_orphaned_dependencies
    a1 = util_spec "a", "1" do |s|
      s.executables = ["exec"]
      s.add_dependency "b"
    end

    b1 = util_spec "b", "1" do |s|
      s.add_dependency "c", "1"
    end

    b2 = util_spec "b", "2" do |s|
      s.add_dependency "c", "2"
    end

    c1 = util_spec "c", "1"

    install_specs c1, b1, b2, a1

    # c2 is missing, and b2 which has it as a dependency will be activated, so we should get an error about the orphaned dependency

    e = assert_raise Gem::UnsatisfiableDependencyError do
      load Gem.activate_bin_path("a", "exec", ">= 0")
    end

    assert_equal "Unable to resolve dependency: 'b (>= 0)' requires 'c (= 2)'", e.message
  end

  def test_activate_bin_path_in_debug_mode
    a1 = util_spec "a", "1" do |s|
      s.executables = ["exec"]
    end

    install_specs a1

    require "open3"
    output, status = Open3.capture2e(
      { "GEM_HOME" => Gem.paths.home, "DEBUG_RESOLVER" => "1" },
      *ruby_with_rubygems_in_load_path, "-e", "\"Gem.activate_bin_path('a', 'exec', '>= 0')\""
    )

    assert status.success?, output
  end

  def test_activate_bin_path_selects_exact_bundler_version_if_present
    bundler_latest = util_spec "bundler", "2.0.1" do |s|
      s.executables = ["bundle"]
    end

    bundler_previous = util_spec "bundler", "2.0.0" do |s|
      s.executables = ["bundle"]
    end

    install_specs bundler_latest, bundler_previous

    File.open("Gemfile.lock", "w") do |f|
      f.write <<~L
        GEM
          remote: https://rubygems.org/
          specs:

        PLATFORMS
          ruby

        DEPENDENCIES

        BUNDLED WITH
          2.0.0
      L
    end

    File.open("Gemfile", "w") {|f| f.puts('source "https://rubygems.org"') }

    load Gem.activate_bin_path("bundler", "bundle", ">= 0.a")

    assert_equal %w[bundler-2.0.0], loaded_spec_names
  end

  def test_activate_bin_path_respects_underscore_selection_if_given
    bundler_latest = util_spec "bundler", "2.0.1" do |s|
      s.executables = ["bundle"]
    end

    bundler_previous = util_spec "bundler", "1.17.3" do |s|
      s.executables = ["bundle"]
    end

    install_specs bundler_latest, bundler_previous

    File.open("Gemfile.lock", "w") do |f|
      f.write <<~L
        GEM
          remote: https://rubygems.org/
          specs:

        PLATFORMS
          ruby

        DEPENDENCIES

        BUNDLED WITH
          2.0.1
      L
    end

    File.open("Gemfile", "w") {|f| f.puts('source "https://rubygems.org"') }

    load Gem.activate_bin_path("bundler", "bundle", "= 1.17.3")

    assert_equal %w[bundler-1.17.3], loaded_spec_names
  end

  def test_activate_bin_path_gives_proper_error_for_bundler_when_underscore_selection_given
    File.open("Gemfile.lock", "w") do |f|
      f.write <<~L
        GEM
          remote: https://rubygems.org/
          specs:

        PLATFORMS
          ruby

        DEPENDENCIES

        BUNDLED WITH
          2.1.4
      L
    end

    File.open("Gemfile", "w") {|f| f.puts('source "https://rubygems.org"') }

    e = assert_raise Gem::GemNotFoundException do
      load Gem.activate_bin_path("bundler", "bundle", "= 2.2.8")
    end

    assert_equal "can't find gem bundler (= 2.2.8) with executable bundle", e.message
  end

  def test_self_bin_path_no_exec_name
    e = assert_raise ArgumentError do
      Gem.bin_path "a"
    end

    assert_equal "you must supply exec_name", e.message
  end

  def test_self_bin_path_bin_name
    install_specs util_exec_gem
    assert_equal @abin_path, Gem.bin_path("a", "abin")
  end

  def test_self_bin_path_bin_name_version
    install_specs util_exec_gem
    assert_equal @abin_path, Gem.bin_path("a", "abin", "4")
  end

  def test_self_bin_path_nonexistent_binfile
    util_spec "a", "2" do |s|
      s.executables = ["exec"]
    end
    assert_raise(Gem::GemNotFoundException) do
      Gem.bin_path("a", "other", "2")
    end
  end

  def test_self_bin_path_no_bin_file
    util_spec "a", "1"
    assert_raise(ArgumentError) do
      Gem.bin_path("a", nil, "1")
    end
  end

  def test_self_bin_path_not_found
    assert_raise(Gem::GemNotFoundException) do
      Gem.bin_path("non-existent", "blah")
    end
  end

  def test_self_bin_path_bin_file_gone_in_latest
    install_specs util_exec_gem
    spec = util_spec "a", "10" do |s|
      s.executables = []
    end
    install_specs spec
    assert_equal @abin_path, Gem.bin_path("a", "abin")
  end

  def test_self_bindir
    assert_equal File.join(@gemhome, "bin"), Gem.bindir
    assert_equal File.join(@gemhome, "bin"), Gem.bindir(Gem.dir)
    assert_equal File.join(@gemhome, "bin"), Gem.bindir(Pathname.new(Gem.dir))
  end

  def test_self_bindir_default_dir
    default = Gem.default_dir

    assert_equal Gem.default_bindir, Gem.bindir(default)
  end

  def test_self_clear_paths
    assert_match(/gemhome$/, Gem.dir)
    assert_match(/gemhome$/, Gem.path.first)

    Gem.clear_paths

    with_env("GEM_HOME" => "foo", "GEM_PATH" => "bar") do
      assert_equal("foo", Gem.dir)
      assert_equal("bar", Gem.path.first)
    end
  end

  def test_self_configuration
    expected = Gem::ConfigFile.new []
    Gem.configuration = nil

    assert_equal expected, Gem.configuration
  end

  def test_self_default_exec_format
    ruby_install_name "ruby" do
      assert_equal "%s", Gem.default_exec_format
    end
  end

  def test_self_default_exec_format_18
    ruby_install_name "ruby18" do
      assert_equal "%s18", Gem.default_exec_format
    end
  end

  def test_self_default_exec_format_jruby
    ruby_install_name "jruby" do
      assert_equal "j%s", Gem.default_exec_format
    end
  end

  def test_default_path
    vendordir(File.join(@tempdir, "vendor")) do
      FileUtils.rm_rf Gem.user_home

      expected = [Gem.default_dir]

      assert_equal expected, Gem.default_path
    end
  end

  def test_default_path_missing_vendor
    vendordir(nil) do
      FileUtils.rm_rf Gem.user_home

      expected = [Gem.default_dir]

      assert_equal expected, Gem.default_path
    end
  end

  def test_default_path_user_home
    vendordir(File.join(@tempdir, "vendor")) do
      expected = [Gem.user_dir, Gem.default_dir]

      assert_equal expected, Gem.default_path
    end
  end

  def test_default_path_vendor_dir
    vendordir(File.join(@tempdir, "vendor")) do
      FileUtils.mkdir_p Gem.vendor_dir

      FileUtils.rm_rf Gem.user_home

      expected = [Gem.default_dir, Gem.vendor_dir]

      assert_equal expected, Gem.default_path
    end
  end

  def test_self_default_sources
    Gem.remove_instance_variable :@default_sources
    assert_equal %w[https://rubygems.org/], Gem.default_sources
  end

  def test_self_dir
    assert_equal @gemhome, Gem.dir
  end

  def test_self_ensure_gem_directories
    FileUtils.rm_r @gemhome
    Gem.use_paths @gemhome

    Gem.ensure_gem_subdirectories @gemhome

    assert_path_exist File.join @gemhome, "build_info"
    assert_path_exist File.join @gemhome, "cache"
    assert_path_exist File.join @gemhome, "doc"
    assert_path_exist File.join @gemhome, "extensions"
    assert_path_exist File.join @gemhome, "gems"
    assert_path_exist File.join @gemhome, "specifications"
  end

  def test_self_ensure_gem_directories_permissions
    FileUtils.rm_r @gemhome
    Gem.use_paths @gemhome

    Gem.ensure_gem_subdirectories @gemhome, 0o750

    assert_directory_exists File.join(@gemhome, "cache")

    assert_equal 0o750, File::Stat.new(@gemhome).mode & 0o777
    assert_equal 0o750, File::Stat.new(File.join(@gemhome, "cache")).mode & 0o777
  end unless Gem.win_platform?

  def test_self_ensure_gem_directories_safe_permissions
    FileUtils.rm_r @gemhome
    Gem.use_paths @gemhome

    old_umask = File.umask
    File.umask 0
    Gem.ensure_gem_subdirectories @gemhome

    assert_equal 0, File::Stat.new(@gemhome).mode & 0o002
    assert_equal 0, File::Stat.new(File.join(@gemhome, "cache")).mode & 0o002
  ensure
    File.umask old_umask
  end unless Gem.win_platform?

  def test_self_ensure_gem_directories_missing_parents
    gemdir = File.join @tempdir, "a/b/c/gemdir"
    begin
      FileUtils.rm_rf File.join(@tempdir, "a")
    rescue StandardError
      nil
    end
    refute File.exist?(File.join(@tempdir, "a")),
           "manually remove #{File.join @tempdir, "a"}, tests are broken"
    Gem.use_paths gemdir

    Gem.ensure_gem_subdirectories gemdir

    assert_directory_exists util_cache_dir
  end

  unless Gem.win_platform? || Process.uid.zero? # only for FS that support write protection
    def test_self_ensure_gem_directories_write_protected
      gemdir = File.join @tempdir, "egd"
      begin
        FileUtils.rm_r gemdir
      rescue StandardError
        nil
      end
      refute File.exist?(gemdir), "manually remove #{gemdir}, tests are broken"
      FileUtils.mkdir_p gemdir
      FileUtils.chmod 0o400, gemdir
      Gem.use_paths gemdir

      Gem.ensure_gem_subdirectories gemdir

      refute File.exist?(util_cache_dir)
    ensure
      FileUtils.chmod 0o600, gemdir
    end

    def test_self_ensure_gem_directories_write_protected_parents
      parent = File.join(@tempdir, "egd")
      gemdir = "#{parent}/a/b/c"

      begin
        FileUtils.rm_r parent
      rescue StandardError
        nil
      end
      refute File.exist?(parent), "manually remove #{parent}, tests are broken"
      FileUtils.mkdir_p parent
      FileUtils.chmod 0o400, parent
      Gem.use_paths(gemdir)

      Gem.ensure_gem_subdirectories gemdir

      refute File.exist? File.join(gemdir, "gems")
    ensure
      FileUtils.chmod 0o600, parent
    end

    def test_self_ensure_gem_directories_non_existent_paths
      Gem.ensure_gem_subdirectories "/proc/0123456789/bogus" # should not raise
      Gem.ensure_gem_subdirectories "classpath:/bogus/x" # JRuby embed scenario
    end
  end

  def test_self_extension_dir_shared
    enable_shared "yes" do
      assert_equal Gem.ruby_api_version, Gem.extension_api_version
    end
  end

  def test_self_extension_dir_static
    enable_shared "no" do
      assert_equal "#{Gem.ruby_api_version}-static", Gem.extension_api_version
    end
  end

  def test_self_find_files
    cwd = File.expand_path("test/rubygems", PROJECT_DIR)
    $LOAD_PATH.unshift cwd

    discover_path = File.join "lib", "sff", "discover.rb"

    foo1, foo2 = %w[1 2].map do |version|
      spec = quick_gem "sff", version do |s|
        s.files << discover_path
      end

      write_file(File.join("gems", spec.full_name, discover_path)) do |fp|
        fp.puts "# #{spec.full_name}"
      end

      spec
    end

    Gem.refresh

    expected = [
      File.expand_path("test/rubygems/sff/discover.rb", PROJECT_DIR),
      File.join(foo2.full_gem_path, discover_path),
      File.join(foo1.full_gem_path, discover_path),
    ]

    assert_equal expected, Gem.find_files("sff/discover")
    assert_equal expected, Gem.find_files("sff/**.rb"), "[ruby-core:31730]"
  ensure
    assert_equal cwd, $LOAD_PATH.shift
  end

  def test_self_find_latest_files
    cwd = File.expand_path("test/rubygems", PROJECT_DIR)
    $LOAD_PATH.unshift cwd

    discover_path = File.join "lib", "sff", "discover.rb"

    _, foo2 = %w[1 2].map do |version|
      spec = quick_gem "sff", version do |s|
        s.files << discover_path
      end

      write_file(File.join("gems", spec.full_name, discover_path)) do |fp|
        fp.puts "# #{spec.full_name}"
      end

      spec
    end

    Gem.refresh

    expected = [
      File.expand_path("test/rubygems/sff/discover.rb", PROJECT_DIR),
      File.join(foo2.full_gem_path, discover_path),
    ]

    assert_equal expected, Gem.find_latest_files("sff/discover")
    assert_equal expected, Gem.find_latest_files("sff/**.rb"), "[ruby-core:31730]"
  ensure
    assert_equal cwd, $LOAD_PATH.shift
  end

  def test_self_latest_spec_for
    gems = spec_fetcher do |fetcher|
      fetcher.spec "a", 1
      fetcher.spec "a", "3.a"
      fetcher.spec "a", 2
    end

    spec = Gem.latest_spec_for "a"

    assert_equal gems["a-2"], spec
  end

  def test_self_latest_spec_for_multiple_sources
    uri = "https://example.sample.com/"
    source = Gem::Source.new(uri)
    source_list = Gem::SourceList.new
    source_list << Gem::Source.new(@uri)
    source_list << source
    Gem.sources.replace source_list

    spec_fetcher(uri) do |fetcher|
      fetcher.spec "a", 1.1
    end

    gems = spec_fetcher do |fetcher|
      fetcher.spec "a", 1
      fetcher.spec "a", "3.a"
      fetcher.spec "a", 2
    end
    spec = Gem.latest_spec_for "a"
    assert_equal gems["a-2"], spec
  end

  def test_self_latest_rubygems_version
    spec_fetcher do |fetcher|
      fetcher.spec "rubygems-update", "1.8.23"
      fetcher.spec "rubygems-update", "1.8.24"
      fetcher.spec "rubygems-update", "2.0.0.preview3"
    end

    version = Gem.latest_rubygems_version

    assert_equal Gem::Version.new("1.8.24"), version
  end

  def test_self_latest_version_for
    spec_fetcher do |fetcher|
      fetcher.spec "a", 1
      fetcher.spec "a", 2
      fetcher.spec "a", "3.a"
    end

    version = Gem.latest_version_for "a"

    assert_equal Gem::Version.new(2), version
  end

  def test_self_latest_version_for_multiple_sources
    uri = "https://example.sample.com/"
    source = Gem::Source.new(uri)
    source_list = Gem::SourceList.new
    source_list << Gem::Source.new(@uri)
    source_list << source
    Gem.sources.replace source_list

    spec_fetcher(uri) do |fetcher|
      fetcher.spec "a", 1.1
    end

    spec_fetcher do |fetcher|
      fetcher.spec "a", 1
      fetcher.spec "a", 2
      fetcher.spec "a", "3.a"
    end

    version = Gem.latest_version_for "a"

    assert_equal Gem::Version.new(2), version
  end

  def test_self_loaded_specs
    foo = util_spec "foo"
    install_gem foo

    foo.activate

    assert_equal true, Gem.loaded_specs.keys.include?("foo")
  end

  def test_self_path
    assert_equal [Gem.dir], Gem.path
  end

  def test_self_path_default
    ENV.delete "GEM_HOME"
    ENV.delete "GEM_PATH"

    Gem.instance_variable_set :@paths, nil

    assert_equal [Gem.default_path, Gem.dir].flatten.uniq, Gem.path
  end

  def test_self_path_ENV_PATH
    path_count = Gem.path.size
    Gem.clear_paths

    ENV["GEM_PATH"] = @additional.join(File::PATH_SEPARATOR)

    assert_equal @additional, Gem.path[0,2]

    assert_equal path_count + @additional.size, Gem.path.size,
                 "extra path components: #{Gem.path[2..-1].inspect}"
    assert_equal Gem.dir, Gem.path.last
  end

  def test_self_path_duplicate
    Gem.clear_paths
    util_ensure_gem_dirs
    dirs = @additional + [@gemhome] + [File.join(@tempdir, "a")]

    ENV["GEM_HOME"] = @gemhome
    ENV["GEM_PATH"] = dirs.join File::PATH_SEPARATOR

    assert_equal @gemhome, Gem.dir

    paths = [Gem.dir]
    assert_equal @additional + paths, Gem.path
  end

  def test_self_path_overlap
    Gem.clear_paths

    util_ensure_gem_dirs
    ENV["GEM_HOME"] = @gemhome
    ENV["GEM_PATH"] = @additional.join(File::PATH_SEPARATOR)

    assert_equal @gemhome, Gem.dir

    paths = [Gem.dir]
    assert_equal @additional + paths, Gem.path
  end

  def test_self_platforms
    assert_equal [Gem::Platform::RUBY, Gem::Platform.local], Gem.platforms
  end

  def test_self_prefix
    assert_equal PROJECT_DIR, Gem.prefix
  end

  def test_self_prefix_libdir
    orig_libdir = RbConfig::CONFIG["libdir"]
    RbConfig::CONFIG["libdir"] = PROJECT_DIR

    assert_nil Gem.prefix
  ensure
    RbConfig::CONFIG["libdir"] = orig_libdir
  end

  def test_self_prefix_sitelibdir
    orig_sitelibdir = RbConfig::CONFIG["sitelibdir"]
    RbConfig::CONFIG["sitelibdir"] = PROJECT_DIR

    assert_nil Gem.prefix
  ensure
    RbConfig::CONFIG["sitelibdir"] = orig_sitelibdir
  end

  def test_self_read_binary
    File.open "test", "w" do |io|
      io.write "\xCF\x80"
    end

    assert_equal ["\xCF", "\x80"], Gem.read_binary("test").chars.to_a

    pend "chmod not supported" if Gem.win_platform?

    begin
      File.chmod 0o444, "test"

      assert_equal ["\xCF", "\x80"], Gem.read_binary("test").chars.to_a
    ensure
      File.chmod 0o644, "test"
    end
  end

  def test_self_refresh
    util_make_gems

    a1_spec = @a1.spec_file
    moved_path = File.join @tempdir, File.basename(a1_spec)

    FileUtils.mv a1_spec, moved_path

    Gem.refresh

    refute_includes Gem::Specification.all_names, @a1.full_name

    FileUtils.mv moved_path, a1_spec

    Gem.refresh

    assert_includes Gem::Specification.all_names, @a1.full_name
  end

  def test_self_refresh_keeps_loaded_specs_activated
    util_make_gems

    a1_spec = @a1.spec_file
    moved_path = File.join @tempdir, File.basename(a1_spec)

    FileUtils.mv a1_spec, moved_path

    Gem.refresh

    s = Gem::Specification.first
    s.activate

    Gem.refresh

    Gem::Specification.each {|spec| assert spec.activated? if spec == s }

    Gem.loaded_specs.delete(s)
    Gem.refresh
  end

  def test_activated_specs_does_not_cause_duplicates_when_looping_through_specs
    util_make_gems

    s = Gem::Specification.first
    s.activate

    Gem.refresh

    assert_equal 1, Gem::Specification.count {|spec| spec.full_name == s.full_name }

    Gem.loaded_specs.delete(s)
    Gem.refresh
  end

  def test_self_ruby_escaping_spaces_in_path
    with_clean_path_to_ruby do
      with_rb_config_ruby("C:/Ruby 1.8/bin/ruby.exe") do
        assert_equal "\"C:/Ruby 1.8/bin/ruby.exe\"", Gem.ruby
      end
    end
  end

  def test_self_ruby_path_without_spaces
    with_clean_path_to_ruby do
      with_rb_config_ruby("C:/Ruby18/bin/ruby.exe") do
        assert_equal "C:/Ruby18/bin/ruby.exe", Gem.ruby
      end
    end
  end

  def test_self_ruby_api_version
    orig_ruby_version = RbConfig::CONFIG["ruby_version"]
    RbConfig::CONFIG["ruby_version"] = "1.2.3"

    Gem.instance_variable_set :@ruby_api_version, nil

    assert_equal "1.2.3", Gem.ruby_api_version
  ensure
    Gem.instance_variable_set :@ruby_api_version, nil

    RbConfig::CONFIG["ruby_version"] = orig_ruby_version
  end

  def test_self_env_requirement
    ENV["GEM_REQUIREMENT_FOO"] = ">= 1.2.3"
    ENV["GEM_REQUIREMENT_BAR"] = "1.2.3"
    ENV["GEM_REQUIREMENT_BAZ"] = "abcd"

    assert_equal Gem::Requirement.create(">= 1.2.3"), Gem.env_requirement("foo")
    assert_equal Gem::Requirement.create("1.2.3"), Gem.env_requirement("bAr")
    assert_raise(Gem::Requirement::BadRequirementError) { Gem.env_requirement("baz") }
    assert_equal Gem::Requirement.default, Gem.env_requirement("qux")
  end

  def test_self_ruby_version_with_non_mri_implementations
    util_set_RUBY_VERSION "2.5.0", 0, 60_928, "jruby 9.2.0.0 (2.5.0) 2018-05-24 81156a8 OpenJDK 64-Bit Server VM 25.171-b11 on 1.8.0_171-8u171-b11-0ubuntu0.16.04.1-b11 [linux-x86_64]"

    assert_equal Gem::Version.new("2.5.0"), Gem.ruby_version
  ensure
    util_restore_RUBY_VERSION
  end

  def test_self_ruby_version_with_svn_prerelease
    util_set_RUBY_VERSION "2.6.0", -1, 63_539, "ruby 2.6.0preview2 (2018-05-31 trunk 63539) [x86_64-linux]"

    assert_equal Gem::Version.new("2.6.0.preview2"), Gem.ruby_version
  ensure
    util_restore_RUBY_VERSION
  end

  def test_self_ruby_version_with_git_prerelease
    util_set_RUBY_VERSION "2.7.0", -1, "b563439274a402e33541f5695b1bfd4ac1085638", "ruby 2.7.0preview3 (2019-11-23 master b563439274) [x86_64-linux]"

    assert_equal Gem::Version.new("2.7.0.preview3"), Gem.ruby_version
  ensure
    util_restore_RUBY_VERSION
  end

  def test_self_ruby_version_with_non_mri_implementations_with_mri_prerelase_compatibility
    util_set_RUBY_VERSION "2.6.0", -1, 63_539, "weirdjruby 9.2.0.0 (2.6.0preview2) 2018-05-24 81156a8 OpenJDK 64-Bit Server VM 25.171-b11 on 1.8.0_171-8u171-b11-0ubuntu0.16.04.1-b11 [linux-x86_64]", "weirdjruby", "9.2.0.0"

    assert_equal Gem::Version.new("2.6.0.preview2"), Gem.ruby_version
  ensure
    util_restore_RUBY_VERSION
  end

  def test_self_ruby_version_with_svn_trunk
    util_set_RUBY_VERSION "1.9.2", -1, 23_493, "ruby 1.9.2dev (2009-05-20 trunk 23493) [x86_64-linux]"

    assert_equal Gem::Version.new("1.9.2.dev"), Gem.ruby_version
  ensure
    util_restore_RUBY_VERSION
  end

  def test_self_ruby_version_with_git_master
    util_set_RUBY_VERSION "2.7.0", -1, "5de284ec78220e75643f89b454ce999da0c1c195", "ruby 2.7.0dev (2019-12-23T01:37:30Z master 5de284ec78) [x86_64-linux]"

    assert_equal Gem::Version.new("2.7.0.dev"), Gem.ruby_version
  ensure
    util_restore_RUBY_VERSION
  end

  def test_self_rubygems_version
    assert_equal Gem::Version.new(Gem::VERSION), Gem.rubygems_version
  end

  def test_self_paths_eq
    other = File.join @tempdir, "other"
    path = [@userhome, other].join File::PATH_SEPARATOR

    #
    # FIXME remove after fixing test_case
    #
    ENV["GEM_HOME"] = @gemhome
    Gem.paths = { "GEM_PATH" => path }

    assert_equal [@userhome, other, @gemhome], Gem.path
  end

  def test_self_paths_eq_nonexistent_home
    ENV["GEM_HOME"] = @gemhome
    Gem.clear_paths

    other = File.join @tempdir, "other"

    ENV["HOME"] = other

    Gem.paths = { "GEM_PATH" => other }

    assert_equal [other, @gemhome], Gem.path
  end

  def test_self_post_build
    assert_equal 1, Gem.post_build_hooks.length

    Gem.post_build {|installer| }

    assert_equal 2, Gem.post_build_hooks.length
  end

  def test_self_post_install
    assert_equal 1, Gem.post_install_hooks.length

    Gem.post_install {|installer| }

    assert_equal 2, Gem.post_install_hooks.length
  end

  def test_self_done_installing
    assert_empty Gem.done_installing_hooks

    Gem.done_installing {|gems| }

    assert_equal 1, Gem.done_installing_hooks.length
  end

  def test_self_post_reset
    assert_empty Gem.post_reset_hooks

    Gem.post_reset {}

    assert_equal 1, Gem.post_reset_hooks.length
  end

  def test_self_post_uninstall
    assert_equal 1, Gem.post_uninstall_hooks.length

    Gem.post_uninstall {|installer| }

    assert_equal 2, Gem.post_uninstall_hooks.length
  end

  def test_self_pre_install
    assert_equal 1, Gem.pre_install_hooks.length

    Gem.pre_install {|installer| }

    assert_equal 2, Gem.pre_install_hooks.length
  end

  def test_self_pre_reset
    assert_empty Gem.pre_reset_hooks

    Gem.pre_reset {}

    assert_equal 1, Gem.pre_reset_hooks.length
  end

  def test_self_pre_uninstall
    assert_equal 1, Gem.pre_uninstall_hooks.length

    Gem.pre_uninstall {|installer| }

    assert_equal 2, Gem.pre_uninstall_hooks.length
  end

  def test_self_sources
    assert_equal %w[http://gems.example.com/], Gem.sources
    Gem.sources = nil
    Gem.configuration.sources = %w[http://test.example.com/]
    assert_equal %w[http://test.example.com/], Gem.sources
  ensure
    Gem.configuration.sources = nil
  end

  def test_try_activate_returns_true_for_activated_specs
    b = util_spec "b", "1.0" do |spec|
      spec.files << "lib/b.rb"
    end
    install_specs b

    assert Gem.try_activate("b"), "try_activate should return true"
    assert Gem.try_activate("b"), "try_activate should still return true"
  end

  def test_spec_order_is_consistent
    b1 = util_spec "b", "1.0"
    b2 = util_spec "b", "2.0"
    b3 = util_spec "b", "3.0"

    install_specs b1, b2, b3

    specs1 = Gem::Specification.stubs.find_all {|s| s.name == "b" }
    Gem::Specification.reset
    specs2 = Gem::Specification.stubs_for("b")
    assert_equal specs1.map(&:version), specs2.map(&:version)
  end

  def test_self_try_activate_missing_dep
    b = util_spec "b", "1.0"
    a = util_spec "a", "1.0", "b" => ">= 1.0"

    install_specs b, a
    uninstall_gem b

    a_file = File.join a.gem_dir, "lib", "a_file.rb"

    write_file a_file do |io|
      io.puts "# a_file.rb"
    end

    e = assert_raise Gem::MissingSpecError do
      Gem.try_activate "a_file"
    end

    assert_include(e.message, "Could not find 'b' ")
    assert_include(e.message, "at: #{a.spec_file}")
  end

  def test_self_try_activate_missing_prerelease
    b = util_spec "b", "1.0rc1"
    a = util_spec "a", "1.0rc1", "b" => "1.0rc1"

    install_specs b, a
    uninstall_gem b

    a_file = File.join a.gem_dir, "lib", "a_file.rb"

    write_file a_file do |io|
      io.puts "# a_file.rb"
    end

    e = assert_raise Gem::MissingSpecError do
      Gem.try_activate "a_file"
    end

    assert_match(/Could not find 'b' \(= 1.0rc1\)/, e.message)
  end

  def test_self_try_activate_missing_extensions
    spec = util_spec "ext", "1" do |s|
      s.extensions = %w[ext/extconf.rb]
      s.installed_by_version = v("2.2")
    end

    # write the spec without install to simulate a failed install
    write_file spec.spec_file do |io|
      io.write spec.to_ruby_for_cache
    end

    _, err = capture_output do
      refute Gem.try_activate "nonexistent"
    end

    expected = "Ignoring ext-1 because its extensions are not built. " \
               "Try: gem pristine ext --version 1\n"

    assert_equal expected, err
  end

  def test_self_use_paths_with_nils
    orig_home = ENV.delete "GEM_HOME"
    orig_path = ENV.delete "GEM_PATH"
    Gem.use_paths nil, nil
    assert_equal Gem.default_dir, Gem.paths.home
    path = (Gem.default_path + [Gem.paths.home]).uniq
    assert_equal path, Gem.paths.path
  ensure
    ENV["GEM_HOME"] = orig_home
    ENV["GEM_PATH"] = orig_path
  end

  def test_setting_paths_does_not_warn_about_unknown_keys
    stdout, stderr = capture_output do
      Gem.paths = { "foo" => [],
                    "bar" => Object.new,
                    "GEM_HOME" => Gem.paths.home,
                    "GEM_PATH" => "foo" }
    end
    assert_equal ["foo", Gem.paths.home], Gem.paths.path
    assert_equal "", stderr
    assert_equal "", stdout
  end

  def test_setting_paths_does_not_mutate_parameter_object
    Gem.paths = { "GEM_HOME" => Gem.paths.home,
                  "GEM_PATH" => "foo" } .freeze
    assert_equal ["foo", Gem.paths.home], Gem.paths.path
  end

  def test_deprecated_paths=
    stdout, stderr = capture_output do
      Gem.paths = { "GEM_HOME" => Gem.paths.home,
                    "GEM_PATH" => [Gem.paths.home, "foo"] }
    end
    assert_equal [Gem.paths.home, "foo"], Gem.paths.path
    assert_match(/Array values in the parameter to `Gem.paths=` are deprecated.\nPlease use a String or nil/m, stderr)
    assert_equal "", stdout
  end

  def test_self_use_paths
    util_ensure_gem_dirs

    Gem.use_paths @gemhome, @additional

    assert_equal @gemhome, Gem.dir
    assert_equal @additional + [Gem.dir], Gem.path
  end

  def test_self_user_dir
    parts = [@userhome, ".gem", Gem.ruby_engine]
    parts << RbConfig::CONFIG["ruby_version"] unless RbConfig::CONFIG["ruby_version"].empty?

    FileUtils.mkdir_p File.join(parts)

    assert_equal File.join(parts), Gem.user_dir
  end

  def test_self_user_home
    if ENV["HOME"]
      assert_equal ENV["HOME"], Gem.user_home
    else
      assert true, "count this test"
    end
  end

  def test_self_needs
    a = util_spec "a", "1"
    b = util_spec "b", "1", "c" => nil
    c = util_spec "c", "2"

    install_specs a, c, b

    Gem.needs do |r|
      r.gem "a"
      r.gem "b", "= 1"
    end

    activated = Gem::Specification.map(&:full_name)

    assert_equal %w[a-1 b-1 c-2], activated.sort
  end

  def test_self_needs_picks_up_unresolved_deps
    a = util_spec "a", "1"
    b = util_spec "b", "1", "c" => nil
    c = util_spec "c", "2"
    d = util_spec "d", "1", { "e" => "= 1" }, "lib/d#{$$}.rb"
    e = util_spec "e", "1"

    install_specs a, c, b, e, d

    Gem.needs do |r|
      r.gem "a"
      r.gem "b", "= 1"

      require "d#{$$}"
    end

    assert_equal %w[a-1 b-1 c-2 d-1 e-1], loaded_spec_names
  end

  def test_self_gunzip
    input = "\x1F\x8B\b\0\xED\xA3\x1AQ\0\x03\xCBH" \
            "\xCD\xC9\xC9\a\0\x86\xA6\x106\x05\0\0\0"

    output = Gem::Util.gunzip input

    assert_equal "hello", output
    assert_equal Encoding::BINARY, output.encoding
  end

  def test_self_gzip
    input = "hello"

    output = Gem::Util.gzip input

    zipped = StringIO.new output

    assert_equal "hello", Zlib::GzipReader.new(zipped).read
    assert_equal Encoding::BINARY, output.encoding
  end

  def test_self_vendor_dir
    vendordir(File.join(@tempdir, "vendor")) do
      expected =
        File.join RbConfig::CONFIG["vendordir"], "gems",
                  RbConfig::CONFIG["ruby_version"]

      assert_equal expected, Gem.vendor_dir
    end
  end

  def test_self_vendor_dir_ENV_GEM_VENDOR
    ENV["GEM_VENDOR"] = File.join @tempdir, "vendor", "gems"

    assert_equal ENV["GEM_VENDOR"], Gem.vendor_dir
    refute Gem.vendor_dir.frozen?
  end

  def test_self_vendor_dir_missing
    vendordir(nil) do
      assert_nil Gem.vendor_dir
    end
  end

  def test_load_plugins
    plugin_path = File.join "lib", "rubygems_plugin.rb"

    foo1_plugin_path = nil
    foo2_plugin_path = nil
    Dir.chdir @tempdir do
      FileUtils.mkdir_p "lib"
      File.open plugin_path, "w" do |fp|
        fp.puts "class TestGem; PLUGINS_LOADED << 'plugin'; end"
      end

      foo1 = util_spec "foo", "1" do |s|
        s.files << plugin_path
      end
      foo1_plugin_path = File.join(foo1.gem_dir, plugin_path)

      install_gem foo1

      foo2 = util_spec "foo", "2" do |s|
        s.files << plugin_path
      end
      foo2_plugin_path = File.join(foo2.gem_dir, plugin_path)

      install_gem foo2
    end

    Gem::Specification.reset
    PLUGINS_LOADED.clear
    $LOADED_FEATURES.delete(foo1_plugin_path)
    $LOADED_FEATURES.delete(foo2_plugin_path)

    gem "foo"

    Gem.load_plugins

    assert_equal %w[plugin], PLUGINS_LOADED
  end

  def test_load_user_installed_plugins
    @orig_gem_home = ENV["GEM_HOME"]
    ENV["GEM_HOME"] = @gemhome

    plugin_path = File.join "lib", "rubygems_plugin.rb"

    Dir.chdir @tempdir do
      FileUtils.mkdir_p "lib"
      File.open plugin_path, "w" do |fp|
        fp.puts "class TestGem; PLUGINS_LOADED << 'plugin'; end"
      end

      foo = util_spec "foo", "1" do |s|
        s.files << plugin_path
      end

      install_gem_user foo
    end

    Gem.paths = { "GEM_PATH" => [Gem.dir, Gem.user_dir].join(File::PATH_SEPARATOR) }

    gem "foo"

    Gem.load_plugins

    assert_equal %w[plugin], PLUGINS_LOADED
  ensure
    ENV["GEM_HOME"] = @orig_gem_home
  end

  def test_load_env_plugins
    with_plugin("load") { Gem.load_env_plugins }
    begin
      assert_equal :loaded, TEST_PLUGIN_LOAD
    rescue StandardError
      nil
    end

    # Should attempt to cause a StandardError
    with_plugin("standarderror") { Gem.load_env_plugins }
    begin
      assert_equal :loaded, TEST_PLUGIN_STANDARDERROR
    rescue StandardError
      nil
    end

    # Should attempt to cause an Exception
    with_plugin("scripterror") { Gem.load_env_plugins }
    begin
      assert_equal :loaded, TEST_PLUGIN_EXCEPTION
    rescue StandardError
      nil
    end
  end

  def test_gem_path_ordering
    refute_equal Gem.dir, Gem.user_dir

    write_file File.join(@tempdir, "lib", "g.rb") {|fp| fp.puts "" }
    write_file File.join(@tempdir, "lib", "m.rb") {|fp| fp.puts "" }

    g = util_spec "g", "1", nil, "lib/g.rb"
    m = util_spec "m", "1", nil, "lib/m.rb"

    install_gem g, install_dir: Gem.dir
    m0 = install_gem m, install_dir: Gem.dir
    m1 = install_gem m, install_dir: Gem.user_dir

    assert_equal m0.gem_dir, File.join(Gem.dir, "gems", "m-1")
    assert_equal m1.gem_dir, File.join(Gem.user_dir, "gems", "m-1")

    tests = [
      [:dir0, [Gem.dir, Gem.user_dir]],
      [:dir1, [Gem.user_dir, Gem.dir]],
    ]

    tests.each do |name, paths|
      Gem.use_paths paths.first, paths
      Gem.searcher = nil

      assert_equal Gem::Dependency.new("m","1").to_specs,
                   Gem::Dependency.new("m","1").to_specs.sort

      assert_equal \
        [m0.gem_dir, m1.gem_dir],
        Gem::Dependency.new("m","1").to_specs.map(&:gem_dir).uniq.sort,
        "Wrong specs for #{name}"

      spec = Gem::Dependency.new("m","1").to_spec

      assert_equal \
        File.join(paths.first, "gems", "m-1"),
        spec.gem_dir,
        "Wrong spec before require for #{name}"
      refute spec.activated?, "dependency already activated for #{name}"

      gem "m"

      spec = Gem::Dependency.new("m","1").to_spec
      assert spec.activated?, "dependency not activated for #{name}"

      assert_equal \
        File.join(paths.first, "gems", "m-1"),
        spec.gem_dir,
        "Wrong spec after require for #{name}"

      spec.instance_variable_set :@activated, false
      Gem.loaded_specs.delete(spec.name)
      $:.delete(File.join(spec.gem_dir, "lib"))
    end
  end

  def test_gem_path_ordering_short
    write_file File.join(@tempdir, "lib", "g.rb") {|fp| fp.puts "" }
    write_file File.join(@tempdir, "lib", "m.rb") {|fp| fp.puts "" }

    g = util_spec "g", "1", nil, "lib/g.rb"
    m = util_spec "m", "1", nil, "lib/m.rb"

    install_gem g, install_dir: Gem.dir
    install_gem m, install_dir: Gem.dir
    install_gem m, install_dir: Gem.user_dir

    Gem.use_paths Gem.dir, [Gem.dir, Gem.user_dir]

    spec = Gem::Dependency.new("m", "1").to_spec

    assert_equal \
      File.join(Gem.dir, "gems", "m-1"),
      spec.gem_dir,
      "Wrong spec selected"
  end

  def test_register_default_spec
    Gem.clear_default_specs

    old_style = Gem::Specification.new do |spec|
      spec.files = ["foo.rb", "bar.rb"]
    end

    Gem.register_default_spec old_style

    assert_equal old_style, Gem.find_unresolved_default_spec("foo.rb")
    assert_equal old_style, Gem.find_unresolved_default_spec("bar.rb")
    assert_nil              Gem.find_unresolved_default_spec("baz.rb")

    Gem.clear_default_specs

    new_style = Gem::Specification.new do |spec|
      spec.files = ["lib/foo.rb", "ext/bar.rb", "bin/exec", "README"]
      spec.require_paths = ["lib", "ext"]
    end

    Gem.register_default_spec new_style

    assert_equal new_style, Gem.find_unresolved_default_spec("foo.rb")
    assert_equal new_style, Gem.find_unresolved_default_spec("bar.rb")
    assert_nil              Gem.find_unresolved_default_spec("exec")
    assert_nil              Gem.find_unresolved_default_spec("README")
  end

  def test_register_default_spec_old_style_with_folder_starting_with_lib
    Gem.clear_default_specs

    old_style = Gem::Specification.new do |spec|
      spec.files = ["libexec/bundle", "foo.rb", "bar.rb"]
    end

    Gem.register_default_spec old_style

    assert_equal old_style, Gem.find_unresolved_default_spec("foo.rb")
  end

  def test_operating_system_defaults
    operating_system_defaults = Gem.operating_system_defaults

    assert !operating_system_defaults.nil?
    assert operating_system_defaults.is_a? Hash
  end

  def test_platform_defaults
    platform_defaults = Gem.platform_defaults

    assert !platform_defaults.nil?
    assert platform_defaults.is_a? Hash
  end

  # Ensure that `Gem.source_date_epoch` is consistent even if
  # $SOURCE_DATE_EPOCH has not been set.
  def test_default_source_date_epoch_doesnt_change
    old_epoch = ENV["SOURCE_DATE_EPOCH"]
    ENV["SOURCE_DATE_EPOCH"] = nil

    # Unfortunately, there is no real way to test this aside from waiting
    # enough for `Time.now.to_i` to change -- which is a whole second.
    #
    # Fortunately, we only need to do this once.
    a = Gem.source_date_epoch
    sleep 1
    b = Gem.source_date_epoch
    assert_equal a, b
  ensure
    ENV["SOURCE_DATE_EPOCH"] = old_epoch
  end

  def test_data_home_default
    expected = File.join(@userhome, ".local", "share")
    assert_equal expected, Gem.data_home
  end

  def test_data_home_from_env
    ENV["XDG_DATA_HOME"] = expected = "/test/data/home"
    assert_equal expected, Gem.data_home
  end

  def test_state_home_default
    Gem.instance_variable_set :@state_home, nil
    Gem.data_home # memoize @data_home, to demonstrate GH-6418
    expected = File.join(@userhome, ".local", "state")
    assert_equal expected, Gem.state_home
  end

  def test_state_home_from_env
    Gem.instance_variable_set :@state_home, nil
    Gem.data_home # memoize @data_home, to demonstrate GH-6418
    ENV["XDG_STATE_HOME"] = expected = "/test/state/home"
    assert_equal expected, Gem.state_home
  end

  private

  def ruby_install_name(name)
    with_clean_path_to_ruby do
      orig_ruby_install_name = RbConfig::CONFIG["ruby_install_name"]
      RbConfig::CONFIG["ruby_install_name"] = name

      begin
        yield
      ensure
        if orig_ruby_install_name
          RbConfig::CONFIG["ruby_install_name"] = orig_ruby_install_name
        else
          RbConfig::CONFIG.delete "ruby_install_name"
        end
      end
    end
  end

  def with_rb_config_ruby(path)
    rb_config_singleton_class = class << RbConfig; self; end
    orig_path = RbConfig.ruby

    redefine_method(rb_config_singleton_class, :ruby, path)

    yield
  ensure
    redefine_method(rb_config_singleton_class, :ruby, orig_path)
  end

  def redefine_method(base, method, new_result)
    base.alias_method(method, method)
    base.define_method(method) { new_result }
  end

  def with_plugin(path)
    test_plugin_path = File.expand_path("test/rubygems/plugin/#{path}",
                                        PROJECT_DIR)

    # A single test plugin should get loaded once only, in order to preserve
    # sane test semantics.
    refute_includes $LOAD_PATH, test_plugin_path
    $LOAD_PATH.unshift test_plugin_path

    capture_output do
      yield
    end
  ensure
    $LOAD_PATH.delete test_plugin_path
  end

  def util_ensure_gem_dirs
    Gem.ensure_gem_subdirectories @gemhome

    #
    # FIXME what does this solve precisely? -ebh
    #
    @additional.each do |_dir|
      Gem.ensure_gem_subdirectories @gemhome
    end
  end

  def util_exec_gem
    spec, _ = util_spec "a", "4" do |s|
      s.executables = ["exec", "abin"]
    end

    @exec_path = File.join spec.full_gem_path, spec.bindir, "exec"
    @abin_path = File.join spec.full_gem_path, spec.bindir, "abin"
    spec
  end

  def util_cache_dir
    File.join Gem.dir, "cache"
  end
end
