[rubygems/rubygems] Copy files specific to testing rubygems to `test`

https://github.com/rubygems/rubygems/commit/aa390a3500

4 files changed, 2365 insertions, 0 deletions

diff --git a/test/rubygems/installer_test_case.rb b/test/rubygems/installer_test_case.rb
new file mode 100644
index 0000000000..416dac7be6
--- /dev/null
+++ b/test/rubygems/installer_test_case.rb
@@ -0,0 +1,247 @@
+# frozen_string_literal: true
+require 'rubygems/test_case'
+require 'rubygems/installer'
+
+class Gem::Installer
+  ##
+  # Available through requiring rubygems/installer_test_case
+
+  attr_writer :bin_dir
+
+  ##
+  # Available through requiring rubygems/installer_test_case
+
+  attr_writer :build_args
+
+  ##
+  # Available through requiring rubygems/installer_test_case
+
+  attr_writer :gem_dir
+
+  ##
+  # Available through requiring rubygems/installer_test_case
+
+  attr_writer :force
+
+  ##
+  # Available through requiring rubygems/installer_test_case
+
+  attr_writer :format
+
+  ##
+  # Available through requiring rubygems/installer_test_case
+
+  attr_writer :gem_home
+
+  ##
+  # Available through requiring rubygems/installer_test_case
+
+  attr_writer :env_shebang
+
+  ##
+  # Available through requiring rubygems/installer_test_case
+
+  attr_writer :ignore_dependencies
+
+  ##
+  # Available through requiring rubygems/installer_test_case
+
+  attr_writer :format_executable
+
+  ##
+  # Available through requiring rubygems/installer_test_case
+
+  attr_writer :security_policy
+
+  ##
+  # Available through requiring rubygems/installer_test_case
+
+  attr_writer :wrappers
+end
+
+##
+# A test case for Gem::Installer.
+
+class Gem::InstallerTestCase < Gem::TestCase
+  def setup
+    super
+
+    Gem::Installer.path_warning = false
+  end
+
+  ##
+  # The path where installed executables live
+
+  def util_inst_bindir
+    File.join @gemhome, "bin"
+  end
+
+  ##
+  # Adds an executable named "executable" to +spec+ with the given +shebang+.
+  #
+  # The executable is also written to the bin dir in @tmpdir and the installed
+  # gem directory for +spec+.
+
+  def util_make_exec(spec = @spec, shebang = "#!/usr/bin/ruby", bindir = "bin")
+    spec.executables = %w[executable]
+    spec.bindir = bindir
+
+    exec_path = spec.bin_file "executable"
+    write_file exec_path do |io|
+      io.puts shebang
+    end
+
+    bin_path = File.join @tempdir, "bin", "executable"
+    write_file bin_path do |io|
+      io.puts shebang
+    end
+  end
+
+  ##
+  # Creates the following instance variables:
+  #
+  # @spec::
+  #   a spec named 'a', intended for regular installs
+  #
+  # @gem::
+  #   the path to a built gem from @spec
+  #
+  # And returns a Gem::Installer for the @spec that installs into @gemhome
+
+  def setup_base_installer(force = true)
+    @gem = setup_base_gem
+    util_installer @spec, @gemhome, false, force
+  end
+
+  ##
+  # Creates the following instance variables:
+  #
+  # @spec::
+  #   a spec named 'a', intended for regular installs
+  #
+  # And returns a gem built for the @spec
+
+  def setup_base_gem
+    @spec = setup_base_spec
+    util_build_gem @spec
+    @spec.cache_file
+  end
+
+  ##
+  # Sets up a generic specification for testing the rubygems installer
+  #
+  # And returns it
+
+  def setup_base_spec
+    quick_gem 'a' do |spec|
+      util_make_exec spec
+    end
+  end
+
+  ##
+  # Creates the following instance variables:
+  #
+  # @spec::
+  #   a spec named 'a', intended for regular installs
+  # @user_spec::
+  #   a spec named 'b', intended for user installs
+  #
+  # @gem::
+  #   the path to a built gem from @spec
+  # @user_gem::
+  #   the path to a built gem from @user_spec
+  #
+  # And returns a Gem::Installer for the @user_spec that installs into Gem.user_dir
+
+  def setup_base_user_installer
+    @user_spec = quick_gem 'b' do |spec|
+      util_make_exec spec
+    end
+
+    util_build_gem @user_spec
+
+    @user_gem = @user_spec.cache_file
+
+    util_installer @user_spec, Gem.user_dir, :user
+  end
+
+  ##
+  # Sets up the base @gem, builds it and returns an installer for it.
+  #
+  def util_setup_installer(&block)
+    @gem = setup_base_gem
+
+    util_setup_gem(&block)
+  end
+
+  ##
+  # Builds the @spec gem and returns an installer for it.  The built gem
+  # includes:
+  #
+  #   bin/executable
+  #   lib/code.rb
+  #   ext/a/mkrf_conf.rb
+
+  def util_setup_gem(ui = @ui, force = true)
+    @spec.files << File.join('lib', 'code.rb')
+    @spec.extensions << File.join('ext', 'a', 'mkrf_conf.rb')
+
+    Dir.chdir @tempdir do
+      FileUtils.mkdir_p 'bin'
+      FileUtils.mkdir_p 'lib'
+      FileUtils.mkdir_p File.join('ext', 'a')
+
+      File.open File.join('bin', 'executable'), 'w' do |f|
+        f.puts "raise 'ran executable'"
+      end
+
+      File.open File.join('lib', 'code.rb'), 'w' do |f|
+        f.puts '1'
+      end
+
+      File.open File.join('ext', 'a', 'mkrf_conf.rb'), 'w' do |f|
+        f << <<-EOF
+          File.open 'Rakefile', 'w' do |rf| rf.puts "task :default" end
+        EOF
+      end
+
+      yield @spec if block_given?
+
+      use_ui ui do
+        FileUtils.rm_f @gem
+
+        @gem = Gem::Package.build @spec
+      end
+    end
+
+    Gem::Installer.at @gem, :force => force
+  end
+
+  ##
+  # Creates an installer for +spec+ that will install into +gem_home+.  If
+  # +user+ is true a user-install will be performed.
+
+  def util_installer(spec, gem_home, user=false, force=true)
+    Gem::Installer.at(spec.cache_file,
+                       :install_dir => gem_home,
+                       :user_install => user,
+                       :force => force)
+  end
+
+  @@symlink_supported = nil
+
+  # This is needed for Windows environment without symlink support enabled (the default
+  # for non admin) to be able to skip test for features using symlinks.
+  def symlink_supported?
+    if @@symlink_supported.nil?
+      begin
+        File.symlink("", "")
+      rescue Errno::ENOENT, Errno::EEXIST
+        @@symlink_supported = true
+      rescue NotImplementedError, SystemCallError
+        @@symlink_supported = false
+      end
+    end
+    @@symlink_supported
+  end
+end
diff --git a/test/rubygems/package/tar_test_case.rb b/test/rubygems/package/tar_test_case.rb
new file mode 100644
index 0000000000..1161d0a5a8
--- /dev/null
+++ b/test/rubygems/package/tar_test_case.rb
@@ -0,0 +1,139 @@
+# frozen_string_literal: true
+require 'rubygems/test_case'
+require 'rubygems/package'
+
+##
+# A test case for Gem::Package::Tar* classes
+
+class Gem::Package::TarTestCase < Gem::TestCase
+  def ASCIIZ(str, length)
+    str + "\0" * (length - str.length)
+  end
+
+  def SP(s)
+    s + " "
+  end
+
+  def SP_Z(s)
+    s + " \0"
+  end
+
+  def Z(s)
+    s + "\0"
+  end
+
+  def assert_headers_equal(expected, actual)
+    expected = expected.to_s unless String === expected
+    actual = actual.to_s unless String === actual
+
+    fields = %w[
+      name 100
+      mode 8
+      uid 8
+      gid 8
+      size 12
+      mtime 12
+      checksum 8
+      typeflag 1
+      linkname 100
+      magic 6
+      version 2
+      uname 32
+      gname 32
+      devmajor 8
+      devminor 8
+      prefix 155
+    ]
+
+    offset = 0
+
+    until fields.empty? do
+      name = fields.shift
+      length = fields.shift.to_i
+
+      if name == "checksum"
+        chksum_off = offset
+        offset += length
+        next
+      end
+
+      assert_equal expected[offset, length], actual[offset, length],
+                   "Field #{name} of the tar header differs."
+
+      offset += length
+    end
+
+    assert_equal expected[chksum_off, 8], actual[chksum_off, 8]
+  end
+
+  def calc_checksum(header)
+    sum = header.unpack("C*").inject{|s,a| s + a }
+    SP(Z(to_oct(sum, 6)))
+  end
+
+  def header(type, fname, dname, length, mode, mtime, checksum = nil, linkname = "")
+    checksum ||= " " * 8
+
+    arr = [                  # struct tarfile_entry_posix
+      ASCIIZ(fname, 100),    # char name[100];     ASCII + (Z unless filled)
+      Z(to_oct(mode, 7)),    # char mode[8];       0 padded, octal null
+      Z(to_oct(0, 7)),       # char uid[8];        ditto
+      Z(to_oct(0, 7)),       # char gid[8];        ditto
+      Z(to_oct(length, 11)), # char size[12];      0 padded, octal, null
+      Z(to_oct(mtime, 11)),  # char mtime[12];     0 padded, octal, null
+      checksum,              # char checksum[8];   0 padded, octal, null, space
+      type,                  # char typeflag[1];   file: "0"  dir: "5"
+      ASCIIZ(linkname, 100), # char linkname[100]; ASCII + (Z unless filled)
+      "ustar\0",             # char magic[6];      "ustar\0"
+      "00",                  # char version[2];    "00"
+      ASCIIZ("wheel", 32),   # char uname[32];     ASCIIZ
+      ASCIIZ("wheel", 32),   # char gname[32];     ASCIIZ
+      Z(to_oct(0, 7)),       # char devmajor[8];   0 padded, octal, null
+      Z(to_oct(0, 7)),       # char devminor[8];   0 padded, octal, null
+      ASCIIZ(dname, 155), # char prefix[155];   ASCII + (Z unless filled)
+    ]
+
+    h = arr.join
+    ret = h + "\0" * (512 - h.size)
+    assert_equal(512, ret.size)
+    ret
+  end
+
+  def tar_dir_header(name, prefix, mode, mtime)
+    h = header("5", name, prefix, 0, mode, mtime)
+    checksum = calc_checksum(h)
+    header("5", name, prefix, 0, mode, mtime, checksum)
+  end
+
+  def tar_file_header(fname, dname, mode, length, mtime)
+    h = header("0", fname, dname, length, mode, mtime)
+    checksum = calc_checksum(h)
+    header("0", fname, dname, length, mode, mtime, checksum)
+  end
+
+  def tar_symlink_header(fname, prefix, mode, mtime, linkname)
+    h = header("2", fname, prefix, 0, mode, mtime, nil, linkname)
+    checksum = calc_checksum(h)
+    header("2", fname, prefix, 0, mode, mtime, checksum, linkname)
+  end
+
+  def to_oct(n, pad_size)
+    "%0#{pad_size}o" % n
+  end
+
+  def util_entry(tar)
+    io = TempIO.new tar
+
+    header = Gem::Package::TarHeader.from io
+
+    Gem::Package::TarReader::Entry.new header, io
+  end
+
+  def util_dir_entry
+    util_entry tar_dir_header("foo", "bar", 0, Time.now)
+  end
+
+  def util_symlink_entry
+    util_entry tar_symlink_header("foo", "bar", 0, Time.now, "link")
+  end
+end
diff --git a/test/rubygems/test_case.rb b/test/rubygems/test_case.rb
new file mode 100644
index 0000000000..f133822271
--- /dev/null
+++ b/test/rubygems/test_case.rb
@@ -0,0 +1,1606 @@
+# frozen_string_literal: true
+
+require 'rubygems'
+
+# If bundler gemspec exists, add to stubs
+bundler_gemspec = File.expand_path("../../../bundler/bundler.gemspec", __FILE__)
+if File.exist?(bundler_gemspec)
+  Gem::Specification.dirs.unshift File.dirname(bundler_gemspec)
+  Gem::Specification.class_variable_set :@@stubs, nil
+  Gem::Specification.stubs
+  Gem::Specification.dirs.shift
+end
+
+begin
+  gem 'test-unit', '~> 3.0'
+rescue Gem::LoadError
+end
+
+begin
+  require 'simplecov'
+  SimpleCov.start do
+    add_filter "/test/"
+    add_filter "/bundler/"
+    add_filter "/lib/rubygems/resolver/molinillo"
+  end
+rescue LoadError
+end
+
+if File.exist?(bundler_gemspec)
+  require_relative '../../bundler/lib/bundler'
+else
+  require 'bundler'
+end
+
+require 'test/unit'
+
+ENV["JARS_SKIP"] = "true" if Gem.java_platform? # avoid unnecessary and noisy `jar-dependencies` post install hook
+
+require 'rubygems/deprecate'
+
+require 'fileutils'
+require 'pathname'
+require 'pp'
+require 'rubygems/package'
+require 'shellwords'
+require 'tmpdir'
+require 'uri'
+require 'zlib'
+require 'benchmark' # stdlib
+require 'rubygems/mock_gem_ui'
+
+module Gem
+
+  ##
+  # Allows setting the gem path searcher.  This method is available when
+  # requiring 'rubygems/test_case'
+
+  def self.searcher=(searcher)
+    @searcher = searcher
+  end
+
+  ##
+  # Allows toggling Windows behavior.  This method is available when requiring
+  # 'rubygems/test_case'
+
+  def self.win_platform=(val)
+    @@win_platform = val
+  end
+
+  ##
+  # Allows setting path to Ruby.  This method is available when requiring
+  # 'rubygems/test_case'
+
+  def self.ruby=(ruby)
+    @ruby = ruby
+  end
+
+  ##
+  # When rubygems/test_case is required the default user interaction is a
+  # MockGemUi.
+
+  module DefaultUserInteraction
+    @ui = Gem::MockGemUi.new
+  end
+end
+
+require "rubygems/command"
+
+class Gem::Command
+  ##
+  # Allows resetting the hash of specific args per command.  This method is
+  # available when requiring 'rubygems/test_case'
+
+  def self.specific_extra_args_hash=(value)
+    @specific_extra_args_hash = value
+  end
+end
+
+##
+# RubyGemTestCase provides a variety of methods for testing rubygems and
+# gem-related behavior in a sandbox.  Through RubyGemTestCase you can install
+# and uninstall gems, fetch remote gems through a stub fetcher and be assured
+# your normal set of gems is not affected.
+
+class Gem::TestCase < Test::Unit::TestCase
+  extend Gem::Deprecate
+
+  attr_accessor :fetcher # :nodoc:
+
+  attr_accessor :gem_repo # :nodoc:
+
+  attr_accessor :uri # :nodoc:
+
+  TEST_PATH = ENV.fetch('RUBYGEMS_TEST_PATH', File.expand_path('../../../test/rubygems', __FILE__))
+
+  def assert_activate(expected, *specs)
+    specs.each do |spec|
+      case spec
+      when String then
+        Gem::Specification.find_by_name(spec).activate
+      when Gem::Specification then
+        spec.activate
+      else
+        flunk spec.inspect
+      end
+    end
+
+    loaded = Gem.loaded_specs.values.map(&:full_name)
+
+    assert_equal expected.sort, loaded.sort if expected
+  end
+
+  def assert_directory_exists(path, msg = nil)
+    msg = build_message(msg, "Expected path '#{path}' to be a directory")
+    assert_path_exist path
+    assert File.directory?(path), msg
+  end
+
+  # https://github.com/seattlerb/minitest/blob/21d9e804b63c619f602f3f4ece6c71b48974707a/lib/minitest/assertions.rb#L188
+  def _synchronize
+    yield
+  end
+
+  # https://github.com/seattlerb/minitest/blob/21d9e804b63c619f602f3f4ece6c71b48974707a/lib/minitest/assertions.rb#L546
+  def capture_subprocess_io
+    _synchronize do
+      begin
+        require "tempfile"
+
+        captured_stdout, captured_stderr = Tempfile.new("out"), Tempfile.new("err")
+
+        orig_stdout, orig_stderr = $stdout.dup, $stderr.dup
+        $stdout.reopen captured_stdout
+        $stderr.reopen captured_stderr
+
+        yield
+
+        $stdout.rewind
+        $stderr.rewind
+
+        return captured_stdout.read, captured_stderr.read
+      ensure
+        captured_stdout.unlink
+        captured_stderr.unlink
+        $stdout.reopen orig_stdout
+        $stderr.reopen orig_stderr
+
+        orig_stdout.close
+        orig_stderr.close
+        captured_stdout.close
+        captured_stderr.close
+      end
+    end
+  end
+
+  ##
+  # Sets the ENABLE_SHARED entry in RbConfig::CONFIG to +value+ and restores
+  # the original value when the block ends
+
+  def enable_shared(value)
+    enable_shared = RbConfig::CONFIG['ENABLE_SHARED']
+    RbConfig::CONFIG['ENABLE_SHARED'] = value
+
+    yield
+  ensure
+    if enable_shared
+      RbConfig::CONFIG['enable_shared'] = enable_shared
+    else
+      RbConfig::CONFIG.delete 'enable_shared'
+    end
+  end
+
+  ##
+  # Sets the vendordir entry in RbConfig::CONFIG to +value+ and restores the
+  # original value when the block ends
+  #
+  def vendordir(value)
+    vendordir = RbConfig::CONFIG['vendordir']
+
+    if value
+      RbConfig::CONFIG['vendordir'] = value
+    else
+      RbConfig::CONFIG.delete 'vendordir'
+    end
+
+    yield
+  ensure
+    if vendordir
+      RbConfig::CONFIG['vendordir'] = vendordir
+    else
+      RbConfig::CONFIG.delete 'vendordir'
+    end
+  end
+
+  ##
+  # Sets the bindir entry in RbConfig::CONFIG to +value+ and restores the
+  # original value when the block ends
+  #
+  def bindir(value)
+    with_clean_path_to_ruby do
+      bindir = RbConfig::CONFIG['bindir']
+
+      if value
+        RbConfig::CONFIG['bindir'] = value
+      else
+        RbConfig::CONFIG.delete 'bindir'
+      end
+
+      begin
+        yield
+      ensure
+        if bindir
+          RbConfig::CONFIG['bindir'] = bindir
+        else
+          RbConfig::CONFIG.delete 'bindir'
+        end
+      end
+    end
+  end
+
+  ##
+  # Sets the EXEEXT entry in RbConfig::CONFIG to +value+ and restores the
+  # original value when the block ends
+  #
+  def exeext(value)
+    exeext = RbConfig::CONFIG['EXEEXT']
+
+    if value
+      RbConfig::CONFIG['EXEEXT'] = value
+    else
+      RbConfig::CONFIG.delete 'EXEEXT'
+    end
+
+    yield
+  ensure
+    if exeext
+      RbConfig::CONFIG['EXEEXT'] = exeext
+    else
+      RbConfig::CONFIG.delete 'EXEEXT'
+    end
+  end
+
+  def scan_make_command_lines(output)
+    output.scan(/^#{Regexp.escape make_command}(?:[[:blank:]].*)?$/)
+  end
+
+  def parse_make_command_line(line)
+    command, *args = line.shellsplit
+
+    targets = []
+    macros = {}
+
+    args.each do |arg|
+      case arg
+      when /\A(\w+)=/
+        macros[$1] = $'
+      else
+        targets << arg
+      end
+    end
+
+    targets << '' if targets.empty?
+
+    {
+      :command => command,
+      :targets => targets,
+      :macros => macros,
+    }
+  end
+
+  def assert_contains_make_command(target, output, msg = nil)
+    if output.match(/\n/)
+      msg = build_message(msg,
+        "Expected output containing make command \"%s\", but was \n\nBEGIN_OF_OUTPUT\n%sEND_OF_OUTPUT" % [
+          ('%s %s' % [make_command, target]).rstrip,
+          output,
+        ]
+      )
+    else
+      msg = build_message(msg,
+        'Expected make command "%s": %s' % [
+          ('%s %s' % [make_command, target]).rstrip,
+          output,
+        ]
+      )
+    end
+
+    assert scan_make_command_lines(output).any? {|line|
+      make = parse_make_command_line(line)
+
+      if make[:targets].include?(target)
+        yield make, line if block_given?
+        true
+      else
+        false
+      end
+    }, msg
+  end
+
+  include Gem::DefaultUserInteraction
+
+  ##
+  # #setup prepares a sandboxed location to install gems.  All installs are
+  # directed to a temporary directory.  All install plugins are removed.
+  #
+  # If the +RUBY+ environment variable is set the given path is used for
+  # Gem::ruby.  The local platform is set to <tt>i386-mswin32</tt> for Windows
+  # or <tt>i686-darwin8.10.1</tt> otherwise.
+
+  def setup
+    @orig_env = ENV.to_hash
+    @tmp = File.expand_path("tmp")
+
+    FileUtils.mkdir_p @tmp
+
+    ENV['GEM_VENDOR'] = nil
+    ENV['GEMRC'] = nil
+    ENV['XDG_CACHE_HOME'] = nil
+    ENV['XDG_CONFIG_HOME'] = nil
+    ENV['XDG_DATA_HOME'] = nil
+    ENV['SOURCE_DATE_EPOCH'] = nil
+    ENV['BUNDLER_VERSION'] = nil
+
+    @current_dir = Dir.pwd
+    @fetcher     = nil
+
+    @back_ui                       = Gem::DefaultUserInteraction.ui
+    @ui                            = Gem::MockGemUi.new
+    # This needs to be a new instance since we call use_ui(@ui) when we want to
+    # capture output
+    Gem::DefaultUserInteraction.ui = Gem::MockGemUi.new
+
+    @tempdir = Dir.mktmpdir("test_rubygems_", @tmp)
+    @tempdir.tap(&Gem::UNTAINT)
+
+    ENV["TMPDIR"] = @tempdir
+
+    @orig_SYSTEM_WIDE_CONFIG_FILE = Gem::ConfigFile::SYSTEM_WIDE_CONFIG_FILE
+    Gem::ConfigFile.send :remove_const, :SYSTEM_WIDE_CONFIG_FILE
+    Gem::ConfigFile.send :const_set, :SYSTEM_WIDE_CONFIG_FILE,
+                         File.join(@tempdir, 'system-gemrc')
+
+    @gemhome  = File.join @tempdir, 'gemhome'
+    @userhome = File.join @tempdir, 'userhome'
+    ENV["GEM_SPEC_CACHE"] = File.join @tempdir, 'spec_cache'
+
+    @orig_ruby = if ENV['RUBY']
+                   ruby = Gem.ruby
+                   Gem.ruby = ENV['RUBY']
+                   ruby
+                 end
+
+    @git = ENV['GIT'] || (win_platform? ? 'git.exe' : 'git')
+
+    Gem.ensure_gem_subdirectories @gemhome
+    Gem.ensure_default_gem_subdirectories @gemhome
+
+    @orig_LOAD_PATH = $LOAD_PATH.dup
+    $LOAD_PATH.map! do |s|
+      expand_path = File.realpath(s) rescue File.expand_path(s)
+      if expand_path != s
+        expand_path.tap(&Gem::UNTAINT)
+        if s.instance_variable_defined?(:@gem_prelude_index)
+          expand_path.instance_variable_set(:@gem_prelude_index, expand_path)
+        end
+        expand_path.freeze if s.frozen?
+        s = expand_path
+      end
+      s
+    end
+
+    Dir.chdir @tempdir
+
+    ENV['HOME'] = @userhome
+    Gem.instance_variable_set :@config_file, nil
+    Gem.instance_variable_set :@user_home, nil
+    Gem.instance_variable_set :@config_home, nil
+    Gem.instance_variable_set :@data_home, nil
+    Gem.instance_variable_set :@gemdeps, nil
+    Gem.instance_variable_set :@env_requirements_by_name, nil
+    Gem.send :remove_instance_variable, :@ruby_version if
+      Gem.instance_variables.include? :@ruby_version
+
+    FileUtils.mkdir_p @userhome
+
+    ENV['GEM_PRIVATE_KEY_PASSPHRASE'] = PRIVATE_KEY_PASSPHRASE
+
+    if Gem.java_platform?
+      @orig_default_gem_home = RbConfig::CONFIG['default_gem_home']
+      RbConfig::CONFIG['default_gem_home'] = @gemhome
+    else
+      Gem.instance_variable_set(:@default_dir, @gemhome)
+    end
+
+    @orig_bindir = RbConfig::CONFIG["bindir"]
+    RbConfig::CONFIG["bindir"] = File.join @gemhome, "bin"
+
+    Gem::Specification.unresolved_deps.clear
+    Gem.use_paths(@gemhome)
+
+    Gem.loaded_specs.clear
+    Gem.instance_variable_set(:@activated_gem_paths, 0)
+    Gem.clear_default_specs
+    Bundler.reset!
+
+    Gem.configuration.verbose = true
+    Gem.configuration.update_sources = true
+
+    Gem::RemoteFetcher.fetcher = Gem::FakeFetcher.new
+
+    @gem_repo = "http://gems.example.com/"
+    @uri = URI.parse @gem_repo
+    Gem.sources.replace [@gem_repo]
+
+    Gem.searcher = nil
+    Gem::SpecFetcher.fetcher = nil
+
+    @orig_arch = RbConfig::CONFIG['arch']
+
+    if win_platform?
+      util_set_arch 'i386-mswin32'
+    else
+      util_set_arch 'i686-darwin8.10.1'
+    end
+
+    @orig_hooks = {}
+    %w[post_install_hooks done_installing_hooks post_uninstall_hooks pre_uninstall_hooks pre_install_hooks pre_reset_hooks post_reset_hooks post_build_hooks].each do |name|
+      @orig_hooks[name] = Gem.send(name).dup
+    end
+
+    @marshal_version = "#{Marshal::MAJOR_VERSION}.#{Marshal::MINOR_VERSION}"
+    @orig_LOADED_FEATURES = $LOADED_FEATURES.dup
+  end
+
+  ##
+  # #teardown restores the process to its original state and removes the
+  # tempdir
+
+  def teardown
+    $LOAD_PATH.replace @orig_LOAD_PATH if @orig_LOAD_PATH
+    if @orig_LOADED_FEATURES
+      if @orig_LOAD_PATH
+        ($LOADED_FEATURES - @orig_LOADED_FEATURES).each do |feat|
+          $LOADED_FEATURES.delete(feat) if feat.start_with?(@tmp)
+        end
+      else
+        $LOADED_FEATURES.replace @orig_LOADED_FEATURES
+      end
+    end
+
+    RbConfig::CONFIG['arch'] = @orig_arch
+
+    if defined? Gem::RemoteFetcher
+      Gem::RemoteFetcher.fetcher = nil
+    end
+
+    Dir.chdir @current_dir
+
+    FileUtils.rm_rf @tempdir
+
+    ENV.replace(@orig_env)
+
+    Gem::ConfigFile.send :remove_const, :SYSTEM_WIDE_CONFIG_FILE
+    Gem::ConfigFile.send :const_set, :SYSTEM_WIDE_CONFIG_FILE,
+                         @orig_SYSTEM_WIDE_CONFIG_FILE
+
+    Gem.ruby = @orig_ruby if @orig_ruby
+
+    RbConfig::CONFIG['bindir'] = @orig_bindir
+
+    if Gem.java_platform?
+      RbConfig::CONFIG['default_gem_home'] = @orig_default_gem_home
+    else
+      Gem.instance_variable_set :@default_dir, nil
+    end
+
+    Gem::Specification._clear_load_cache
+    Gem::Specification.unresolved_deps.clear
+    Gem::refresh
+
+    @orig_hooks.each do |name, hooks|
+      Gem.send(name).replace hooks
+    end
+
+    @back_ui.close
+  end
+
+  def credential_setup
+    @temp_cred = File.join(@userhome, '.gem', 'credentials')
+    FileUtils.mkdir_p File.dirname(@temp_cred)
+    File.write @temp_cred, ':rubygems_api_key: 701229f217cdf23b1344c7b4b54ca97'
+    File.chmod 0600, @temp_cred
+  end
+
+  def credential_teardown
+    FileUtils.rm_rf @temp_cred
+  end
+
+  def common_installer_setup
+    common_installer_teardown
+
+    Gem.post_build do |installer|
+      @post_build_hook_arg = installer
+      true
+    end
+
+    Gem.post_install do |installer|
+      @post_install_hook_arg = installer
+    end
+
+    Gem.post_uninstall do |uninstaller|
+      @post_uninstall_hook_arg = uninstaller
+    end
+
+    Gem.pre_install do |installer|
+      @pre_install_hook_arg = installer
+      true
+    end
+
+    Gem.pre_uninstall do |uninstaller|
+      @pre_uninstall_hook_arg = uninstaller
+    end
+  end
+
+  def common_installer_teardown
+    Gem.post_build_hooks.clear
+    Gem.post_install_hooks.clear
+    Gem.done_installing_hooks.clear
+    Gem.post_reset_hooks.clear
+    Gem.post_uninstall_hooks.clear
+    Gem.pre_install_hooks.clear
+    Gem.pre_reset_hooks.clear
+    Gem.pre_uninstall_hooks.clear
+  end
+
+  ##
+  # A git_gem is used with a gem dependencies file.  The gem created here
+  # has no files, just a gem specification for the given +name+ and +version+.
+  #
+  # Yields the +specification+ to the block, if given
+
+  def git_gem(name = 'a', version = 1)
+    have_git?
+
+    directory = File.join 'git', name
+    directory = File.expand_path directory
+
+    git_spec = Gem::Specification.new name, version do |specification|
+      yield specification if block_given?
+    end
+
+    FileUtils.mkdir_p directory
+
+    gemspec = "#{name}.gemspec"
+
+    File.open File.join(directory, gemspec), 'w' do |io|
+      io.write git_spec.to_ruby
+    end
+
+    head = nil
+
+    Dir.chdir directory do
+      unless File.exist? '.git'
+        system @git, 'init', '--quiet'
+        system @git, 'config', 'user.name',  'RubyGems Tests'
+        system @git, 'config', 'user.email', 'rubygems@example'
+      end
+
+      system @git, 'add', gemspec
+      system @git, 'commit', '-a', '-m', 'a non-empty commit message', '--quiet'
+      head = Gem::Util.popen(@git, 'rev-parse', 'master').strip
+    end
+
+    return name, git_spec.version, directory, head
+  end
+
+  ##
+  # Skips this test unless you have a git executable
+
+  def have_git?
+    return if in_path? @git
+
+    skip 'cannot find git executable, use GIT environment variable to set'
+  end
+
+  def in_path?(executable) # :nodoc:
+    return true if %r{\A([A-Z]:|/)} =~ executable and File.exist? executable
+
+    ENV['PATH'].split(File::PATH_SEPARATOR).any? do |directory|
+      File.exist? File.join directory, executable
+    end
+  end
+
+  ##
+  # Builds and installs the Gem::Specification +spec+
+
+  def install_gem(spec, options = {})
+    require 'rubygems/installer'
+
+    gem = spec.cache_file
+
+    unless File.exist? gem
+      use_ui Gem::MockGemUi.new do
+        Dir.chdir @tempdir do
+          Gem::Package.build spec
+        end
+      end
+
+      gem = File.join(@tempdir, File.basename(gem)).tap(&Gem::UNTAINT)
+    end
+
+    Gem::Installer.at(gem, options.merge({:wrappers => true})).install
+  end
+
+  ##
+  # Builds and installs the Gem::Specification +spec+ into the user dir
+
+  def install_gem_user(spec)
+    install_gem spec, :user_install => true
+  end
+
+  ##
+  # Uninstalls the Gem::Specification +spec+
+  def uninstall_gem(spec)
+    require 'rubygems/uninstaller'
+
+    Class.new(Gem::Uninstaller) do
+      def ask_if_ok(spec)
+        true
+      end
+    end.new(spec.name, :executables => true, :user_install => true).uninstall
+  end
+
+  ##
+  # Enables pretty-print for all tests
+
+  def mu_pp(obj)
+    s = String.new
+    s = PP.pp obj, s
+    s = s.force_encoding(Encoding.default_external)
+    s.chomp
+  end
+
+  ##
+  # Reads a Marshal file at +path+
+
+  def read_cache(path)
+    File.open path.dup.tap(&Gem::UNTAINT), 'rb' do |io|
+      Marshal.load io.read
+    end
+  end
+
+  ##
+  # Reads a binary file at +path+
+
+  def read_binary(path)
+    Gem.read_binary path
+  end
+
+  ##
+  # Writes a binary file to +path+ which is relative to +@gemhome+
+
+  def write_file(path)
+    path = File.join @gemhome, path unless Pathname.new(path).absolute?
+    dir = File.dirname path
+    FileUtils.mkdir_p dir unless File.directory? dir
+
+    File.open path, 'wb' do |io|
+      yield io if block_given?
+    end
+
+    path
+  end
+
+  ##
+  # Load a YAML string, the psych 3 way
+
+  def load_yaml(yaml)
+    if YAML.respond_to?(:unsafe_load)
+      YAML.unsafe_load(yaml)
+    else
+      YAML.load(yaml)
+    end
+  end
+
+  ##
+  # Load a YAML file, the psych 3 way
+
+  def load_yaml_file(file)
+    if YAML.respond_to?(:unsafe_load_file)
+      YAML.unsafe_load_file(file)
+    else
+      YAML.load_file(file)
+    end
+  end
+
+  def all_spec_names
+    Gem::Specification.map(&:full_name)
+  end
+
+  ##
+  # Creates a Gem::Specification with a minimum of extra work.  +name+ and
+  # +version+ are the gem's name and version,  platform, author, email,
+  # homepage, summary and description are defaulted.  The specification is
+  # yielded for customization.
+  #
+  # The gem is added to the installed gems in +@gemhome+ and the runtime.
+  #
+  # Use this with #write_file to build an installed gem.
+
+  def quick_gem(name, version='2')
+    require 'rubygems/specification'
+
+    spec = Gem::Specification.new do |s|
+      s.platform    = Gem::Platform::RUBY
+      s.name        = name
+      s.version     = version
+      s.author      = 'A User'
+      s.email       = 'example@example.com'
+      s.homepage    = 'http://example.com'
+      s.summary     = "this is a summary"
+      s.description = "This is a test description"
+
+      yield(s) if block_given?
+    end
+
+    written_path = write_file spec.spec_file do |io|
+      io.write spec.to_ruby_for_cache
+    end
+
+    spec.loaded_from = written_path
+
+    Gem::Specification.reset
+
+    return spec
+  end
+
+  ##
+  # Builds a gem from +spec+ and places it in <tt>File.join @gemhome,
+  # 'cache'</tt>.  Automatically creates files based on +spec.files+
+
+  def util_build_gem(spec)
+    dir = spec.gem_dir
+    FileUtils.mkdir_p dir
+
+    Dir.chdir dir do
+      spec.files.each do |file|
+        next if File.exist? file
+        FileUtils.mkdir_p File.dirname(file)
+
+        File.open file, 'w' do |fp|
+          fp.puts "# #{file}"
+        end
+      end
+
+      use_ui Gem::MockGemUi.new do
+        Gem::Package.build spec
+      end
+
+      cache = spec.cache_file
+      FileUtils.mv File.basename(cache), cache
+    end
+  end
+
+  def util_remove_gem(spec)
+    FileUtils.rm_rf spec.cache_file
+    FileUtils.rm_rf spec.spec_file
+  end
+
+  ##
+  # Removes all installed gems from +@gemhome+.
+
+  def util_clear_gems
+    FileUtils.rm_rf File.join(@gemhome, "gems")
+    FileUtils.mkdir File.join(@gemhome, "gems")
+    FileUtils.rm_rf File.join(@gemhome, "specifications")
+    FileUtils.mkdir File.join(@gemhome, "specifications")
+    Gem::Specification.reset
+  end
+
+  ##
+  # Install the provided specs
+
+  def install_specs(*specs)
+    specs.each do |spec|
+      Gem::Installer.for_spec(spec, :force => true).install
+    end
+
+    Gem.searcher = nil
+  end
+
+  ##
+  # Installs the provided default specs including writing the spec file
+
+  def install_default_gems(*specs)
+    specs.each do |spec|
+      installer = Gem::Installer.for_spec(spec, :install_as_default => true)
+      installer.install
+      Gem.register_default_spec(spec)
+    end
+  end
+
+  def loaded_spec_names
+    Gem.loaded_specs.values.map(&:full_name).sort
+  end
+
+  def unresolved_names
+    Gem::Specification.unresolved_deps.values.map(&:to_s).sort
+  end
+
+  def save_loaded_features
+    old_loaded_features = $LOADED_FEATURES.dup
+    yield
+  ensure
+    prefix = File.dirname(__FILE__) + "/"
+    new_features = ($LOADED_FEATURES - old_loaded_features)
+    old_loaded_features.concat(new_features.select {|f| f.rindex(prefix, 0) })
+    $LOADED_FEATURES.replace old_loaded_features
+  end
+
+  def new_default_spec(name, version, deps = nil, *files)
+    spec = util_spec name, version, deps
+
+    spec.loaded_from = File.join(@gemhome, "specifications", "default", spec.spec_name)
+    spec.files = files
+
+    lib_dir = File.join(@tempdir, "default_gems", "lib")
+    lib_dir.instance_variable_set(:@gem_prelude_index, lib_dir)
+    Gem.instance_variable_set(:@default_gem_load_paths, [*Gem.send(:default_gem_load_paths), lib_dir])
+    $LOAD_PATH.unshift(lib_dir)
+    files.each do |file|
+      rb_path = File.join(lib_dir, file)
+      FileUtils.mkdir_p(File.dirname(rb_path))
+      File.open(rb_path, "w") do |rb|
+        rb << "# #{file}"
+      end
+    end
+
+    spec
+  end
+
+  ##
+  # Creates a spec with +name+, +version+.  +deps+ can specify the dependency
+  # or a +block+ can be given for full customization of the specification.
+
+  def util_spec(name, version = 2, deps = nil, *files) # :yields: specification
+    raise "deps or block, not both" if deps and block_given?
+
+    spec = Gem::Specification.new do |s|
+      s.platform    = Gem::Platform::RUBY
+      s.name        = name
+      s.version     = version
+      s.author      = 'A User'
+      s.email       = 'example@example.com'
+      s.homepage    = 'http://example.com'
+      s.summary     = "this is a summary"
+      s.description = "This is a test description"
+
+      s.files.push(*files) unless files.empty?
+
+      yield s if block_given?
+    end
+
+    if deps
+      deps.keys.each do |n|
+        spec.add_dependency n, (deps[n] || '>= 0')
+      end
+    end
+
+    unless files.empty?
+      write_file spec.spec_file do |io|
+        io.write spec.to_ruby_for_cache
+      end
+
+      util_build_gem spec
+
+      FileUtils.rm spec.spec_file
+    end
+
+    return spec
+  end
+
+  ##
+  # Creates a gem with +name+, +version+ and +deps+.  The specification will
+  # be yielded before gem creation for customization.  The gem will be placed
+  # in <tt>File.join @tempdir, 'gems'</tt>.  The specification and .gem file
+  # location are returned.
+
+  def util_gem(name, version, deps = nil, &block)
+    if deps
+      block = proc do |s|
+        deps.keys.each do |n|
+          s.add_dependency n, (deps[n] || '>= 0')
+        end
+      end
+    end
+
+    spec = quick_gem(name, version, &block)
+
+    util_build_gem spec
+
+    cache_file = File.join @tempdir, 'gems', "#{spec.original_name}.gem"
+    FileUtils.mkdir_p File.dirname cache_file
+    FileUtils.mv spec.cache_file, cache_file
+    FileUtils.rm spec.spec_file
+
+    spec.loaded_from = nil
+
+    [spec, cache_file]
+  end
+
+  ##
+  # Gzips +data+.
+
+  def util_gzip(data)
+    out = StringIO.new
+
+    Zlib::GzipWriter.wrap out do |io|
+      io.write data
+    end
+
+    out.string
+  end
+
+  ##
+  # Creates several default gems which all have a lib/code.rb file.  The gems
+  # are not installed but are available in the cache dir.
+  #
+  # +@a1+:: gem a version 1, this is the best-described gem.
+  # +@a2+:: gem a version 2
+  # +@a3a:: gem a version 3.a
+  # +@a_evil9+:: gem a_evil version 9, use this to ensure similarly-named gems
+  #              don't collide with a.
+  # +@b2+:: gem b version 2
+  # +@c1_2+:: gem c version 1.2
+  # +@pl1+:: gem pl version 1, this gem has a legacy platform of i386-linux.
+  #
+  # Additional +prerelease+ gems may also be created:
+  #
+  # +@a2_pre+:: gem a version 2.a
+  # TODO: nuke this and fix tests. this should speed up a lot
+
+  def util_make_gems(prerelease = false)
+    @a1 = quick_gem 'a', '1' do |s|
+      s.files = %w[lib/code.rb]
+      s.require_paths = %w[lib]
+      s.date = Gem::Specification::TODAY - 86400
+      s.homepage = 'http://a.example.com'
+      s.email = %w[example@example.com example2@example.com]
+      s.authors = %w[Example Example2]
+      s.description = <<-DESC
+This line is really, really long.  So long, in fact, that it is more than eighty characters long!  The purpose of this line is for testing wrapping behavior because sometimes people don't wrap their text to eighty characters.  Without the wrapping, the text might not look good in the RSS feed.
+
+Also, a list:
+  * An entry that\'s actually kind of sort
+  * an entry that\'s really long, which will probably get wrapped funny.  That's ok, somebody wasn't thinking straight when they made it more than eighty characters.
+      DESC
+    end
+
+    init = proc do |s|
+      s.files = %w[lib/code.rb]
+      s.require_paths = %w[lib]
+    end
+
+    @a2      = quick_gem('a', '2',      &init)
+    @a3a     = quick_gem('a', '3.a',    &init)
+    @a_evil9 = quick_gem('a_evil', '9', &init)
+    @b2      = quick_gem('b', '2',      &init)
+    @c1_2    = quick_gem('c', '1.2',    &init)
+    @x       = quick_gem('x', '1',      &init)
+    @dep_x   = quick_gem('dep_x', '1') do |s|
+      s.files = %w[lib/code.rb]
+      s.require_paths = %w[lib]
+      s.add_dependency 'x', '>= 1'
+    end
+
+    @pl1 = quick_gem 'pl', '1' do |s| # l for legacy
+      s.files = %w[lib/code.rb]
+      s.require_paths = %w[lib]
+      s.platform = Gem::Platform.new 'i386-linux'
+      s.instance_variable_set :@original_platform, 'i386-linux'
+    end
+
+    if prerelease
+      @a2_pre = quick_gem('a', '2.a', &init)
+      write_file File.join(*%W[gems #{@a2_pre.original_name} lib code.rb])
+      util_build_gem @a2_pre
+    end
+
+    write_file File.join(*%W[gems #{@a1.original_name}      lib code.rb])
+    write_file File.join(*%W[gems #{@a2.original_name}      lib code.rb])
+    write_file File.join(*%W[gems #{@a3a.original_name}     lib code.rb])
+    write_file File.join(*%W[gems #{@a_evil9.original_name} lib code.rb])
+    write_file File.join(*%W[gems #{@b2.original_name}      lib code.rb])
+    write_file File.join(*%W[gems #{@c1_2.original_name}    lib code.rb])
+    write_file File.join(*%W[gems #{@pl1.original_name}     lib code.rb])
+    write_file File.join(*%W[gems #{@x.original_name}       lib code.rb])
+    write_file File.join(*%W[gems #{@dep_x.original_name}   lib code.rb])
+
+    [@a1, @a2, @a3a, @a_evil9, @b2, @c1_2, @pl1, @x, @dep_x].each do |spec|
+      util_build_gem spec
+    end
+
+    FileUtils.rm_r File.join(@gemhome, "gems", @pl1.original_name)
+  end
+
+  ##
+  # Set the platform to +arch+
+
+  def util_set_arch(arch)
+    RbConfig::CONFIG['arch'] = arch
+    platform = Gem::Platform.new arch
+
+    Gem.instance_variable_set :@platforms, nil
+    Gem::Platform.instance_variable_set :@local, nil
+
+    yield if block_given?
+
+    platform
+  end
+
+  ##
+  # Add +spec+ to +@fetcher+ serving the data in the file +path+.
+  # +repo+ indicates which repo to make +spec+ appear to be in.
+
+  def add_to_fetcher(spec, path=nil, repo=@gem_repo)
+    path ||= spec.cache_file
+    @fetcher.data["#{@gem_repo}gems/#{spec.file_name}"] = read_binary(path)
+  end
+
+  ##
+  # Sets up Gem::SpecFetcher to return information from the gems in +specs+.
+
+  def util_setup_spec_fetcher(*specs)
+    all_specs = Gem::Specification.to_a + specs
+    Gem::Specification._resort! all_specs
+
+    spec_fetcher = Gem::SpecFetcher.fetcher
+
+    prerelease, all = all_specs.partition {|spec| spec.version.prerelease? }
+    latest = Gem::Specification._latest_specs all_specs
+
+    spec_fetcher.specs[@uri] = []
+    all.each do |spec|
+      spec_fetcher.specs[@uri] << spec.name_tuple
+    end
+
+    spec_fetcher.latest_specs[@uri] = []
+    latest.each do |spec|
+      spec_fetcher.latest_specs[@uri] << spec.name_tuple
+    end
+
+    spec_fetcher.prerelease_specs[@uri] = []
+    prerelease.each do |spec|
+      spec_fetcher.prerelease_specs[@uri] << spec.name_tuple
+    end
+
+    # HACK for test_download_to_cache
+    unless Gem::RemoteFetcher === @fetcher
+      v = Gem.marshal_version
+
+      specs = all.map {|spec| spec.name_tuple }
+      s_zip = util_gzip Marshal.dump Gem::NameTuple.to_basic specs
+
+      latest_specs = latest.map do |spec|
+        spec.name_tuple
+      end
+
+      l_zip = util_gzip Marshal.dump Gem::NameTuple.to_basic latest_specs
+
+      prerelease_specs = prerelease.map {|spec| spec.name_tuple }
+      p_zip = util_gzip Marshal.dump Gem::NameTuple.to_basic prerelease_specs
+
+      @fetcher.data["#{@gem_repo}specs.#{v}.gz"]            = s_zip
+      @fetcher.data["#{@gem_repo}latest_specs.#{v}.gz"]     = l_zip
+      @fetcher.data["#{@gem_repo}prerelease_specs.#{v}.gz"] = p_zip
+
+      v = Gem.marshal_version
+
+      all_specs.each do |spec|
+        path = "#{@gem_repo}quick/Marshal.#{v}/#{spec.original_name}.gemspec.rz"
+        data = Marshal.dump spec
+        data_deflate = Zlib::Deflate.deflate data
+        @fetcher.data[path] = data_deflate
+      end
+    end
+
+    nil # force errors
+  end
+
+  ##
+  # Deflates +data+
+
+  def util_zip(data)
+    Zlib::Deflate.deflate data
+  end
+
+  def util_set_RUBY_VERSION(version, patchlevel = nil, revision = nil, description = nil, engine = "ruby", engine_version = nil)
+    if Gem.instance_variables.include? :@ruby_version
+      Gem.send :remove_instance_variable, :@ruby_version
+    end
+
+    @RUBY_VERSION        = RUBY_VERSION
+    @RUBY_PATCHLEVEL     = RUBY_PATCHLEVEL     if defined?(RUBY_PATCHLEVEL)
+    @RUBY_REVISION       = RUBY_REVISION       if defined?(RUBY_REVISION)
+    @RUBY_DESCRIPTION    = RUBY_DESCRIPTION    if defined?(RUBY_DESCRIPTION)
+    @RUBY_ENGINE         = RUBY_ENGINE
+    @RUBY_ENGINE_VERSION = RUBY_ENGINE_VERSION if defined?(RUBY_ENGINE_VERSION)
+
+    util_clear_RUBY_VERSION
+
+    Object.const_set :RUBY_VERSION,        version
+    Object.const_set :RUBY_PATCHLEVEL,     patchlevel     if patchlevel
+    Object.const_set :RUBY_REVISION,       revision       if revision
+    Object.const_set :RUBY_DESCRIPTION,    description    if description
+    Object.const_set :RUBY_ENGINE,         engine
+    Object.const_set :RUBY_ENGINE_VERSION, engine_version if engine_version
+  end
+
+  def util_restore_RUBY_VERSION
+    util_clear_RUBY_VERSION
+
+    Object.const_set :RUBY_VERSION,        @RUBY_VERSION
+    Object.const_set :RUBY_PATCHLEVEL,     @RUBY_PATCHLEVEL  if
+      defined?(@RUBY_PATCHLEVEL)
+    Object.const_set :RUBY_REVISION,       @RUBY_REVISION    if
+      defined?(@RUBY_REVISION)
+    Object.const_set :RUBY_DESCRIPTION,    @RUBY_DESCRIPTION if
+      defined?(@RUBY_DESCRIPTION)
+    Object.const_set :RUBY_ENGINE,         @RUBY_ENGINE
+    Object.const_set :RUBY_ENGINE_VERSION, @RUBY_ENGINE_VERSION if
+      defined?(@RUBY_ENGINE_VERSION)
+  end
+
+  def util_clear_RUBY_VERSION
+    Object.send :remove_const, :RUBY_VERSION
+    Object.send :remove_const, :RUBY_PATCHLEVEL     if defined?(RUBY_PATCHLEVEL)
+    Object.send :remove_const, :RUBY_REVISION       if defined?(RUBY_REVISION)
+    Object.send :remove_const, :RUBY_DESCRIPTION    if defined?(RUBY_DESCRIPTION)
+    Object.send :remove_const, :RUBY_ENGINE
+    Object.send :remove_const, :RUBY_ENGINE_VERSION if defined?(RUBY_ENGINE_VERSION)
+  end
+
+  ##
+  # Is this test being run on a Windows platform?
+
+  def self.win_platform?
+    Gem.win_platform?
+  end
+
+  ##
+  # Is this test being run on a Windows platform?
+
+  def win_platform?
+    Gem.win_platform?
+  end
+
+  ##
+  # Is this test being run on a Java platform?
+
+  def self.java_platform?
+    Gem.java_platform?
+  end
+
+  ##
+  # Is this test being run on a Java platform?
+
+  def java_platform?
+    Gem.java_platform?
+  end
+
+  ##
+  # Returns whether or not we're on a version of Ruby built with VC++ (or
+  # Borland) versus Cygwin, Mingw, etc.
+
+  def self.vc_windows?
+    RUBY_PLATFORM.match('mswin')
+  end
+
+  ##
+  # Returns whether or not we're on a version of Ruby built with VC++ (or
+  # Borland) versus Cygwin, Mingw, etc.
+
+  def vc_windows?
+    RUBY_PLATFORM.match('mswin')
+  end
+
+  ##
+  # Returns the make command for the current platform. For versions of Ruby
+  # built on MS Windows with VC++ or Borland it will return 'nmake'. On all
+  # other platforms, including Cygwin, it will return 'make'.
+
+  def self.make_command
+    ENV["make"] || ENV["MAKE"] || (vc_windows? ? 'nmake' : 'make')
+  end
+
+  ##
+  # Returns the make command for the current platform. For versions of Ruby
+  # built on MS Windows with VC++ or Borland it will return 'nmake'. On all
+  # other platforms, including Cygwin, it will return 'make'.
+
+  def make_command
+    ENV["make"] || ENV["MAKE"] || (vc_windows? ? 'nmake' : 'make')
+  end
+
+  ##
+  # Returns whether or not the nmake command could be found.
+
+  def nmake_found?
+    system('nmake /? 1>NUL 2>&1')
+  end
+
+  # In case we're building docs in a background process, this method waits for
+  # that process to exit (or if it's already been reaped, or never happened,
+  # swallows the Errno::ECHILD error).
+  def wait_for_child_process_to_exit
+    Process.wait if Process.respond_to?(:fork)
+  rescue Errno::ECHILD
+  end
+
+  ##
+  # Allows tests to use a random (but controlled) port number instead of
+  # a hardcoded one. This helps CI tools when running parallels builds on
+  # the same builder slave.
+
+  def self.process_based_port
+    @@process_based_port ||= 8000 + $$ % 1000
+  end
+
+  ##
+  # See ::process_based_port
+
+  def process_based_port
+    self.class.process_based_port
+  end
+
+  ##
+  # Allows the proper version of +rake+ to be used for the test.
+
+  def build_rake_in(good=true)
+    gem_ruby = Gem.ruby
+    Gem.ruby = self.class.rubybin
+    env_rake = ENV["rake"]
+    rake = (good ? @@good_rake : @@bad_rake)
+    ENV["rake"] = rake
+    yield rake
+  ensure
+    Gem.ruby = gem_ruby
+    if env_rake
+      ENV["rake"] = env_rake
+    else
+      ENV.delete("rake")
+    end
+  end
+
+  ##
+  # Finds the path to the Ruby executable
+
+  def self.rubybin
+    ruby = ENV["RUBY"]
+    return ruby if ruby
+    ruby = "ruby"
+    rubyexe = "#{ruby}.exe"
+
+    3.times do
+      if File.exist? ruby and File.executable? ruby and !File.directory? ruby
+        return File.expand_path(ruby)
+      end
+      if File.exist? rubyexe and File.executable? rubyexe
+        return File.expand_path(rubyexe)
+      end
+      ruby = File.join("..", ruby)
+    end
+
+    begin
+      Gem.ruby
+    rescue LoadError
+      "ruby"
+    end
+  end
+
+  def ruby_with_rubygems_in_load_path
+    [Gem.ruby, "-I", File.expand_path("../../lib", __dir__)]
+  end
+
+  def with_clean_path_to_ruby
+    orig_ruby = Gem.ruby
+
+    Gem.instance_variable_set :@ruby, nil
+
+    yield
+  ensure
+    Gem.instance_variable_set :@ruby, orig_ruby
+  end
+
+  class << self
+    # :nodoc:
+    ##
+    # Return the join path, with escaping backticks, dollars, and
+    # double-quotes.  Unlike `shellescape`, equal-sign is not escaped.
+
+    private
+
+    def escape_path(*path)
+      path = File.join(*path)
+      if %r{\A[-+:/=@,.\w]+\z} =~ path
+        path
+      else
+        "\"#{path.gsub(/[`$"]/, '\\&')}\""
+      end
+    end
+  end
+
+  @@good_rake = "#{rubybin} #{escape_path(TEST_PATH, 'good_rake.rb')}"
+  @@bad_rake = "#{rubybin} #{escape_path(TEST_PATH, 'bad_rake.rb')}"
+
+  ##
+  # Construct a new Gem::Dependency.
+
+  def dep(name, *requirements)
+    Gem::Dependency.new name, *requirements
+  end
+
+  ##
+  # Constructs a Gem::Resolver::DependencyRequest from a
+  # Gem::Dependency +dep+, a +from_name+ and +from_version+ requesting the
+  # dependency and a +parent+ DependencyRequest
+
+  def dependency_request(dep, from_name, from_version, parent = nil)
+    remote = Gem::Source.new @uri
+
+    unless parent
+      parent_dep = dep from_name, from_version
+      parent = Gem::Resolver::DependencyRequest.new parent_dep, nil
+    end
+
+    spec = Gem::Resolver::IndexSpecification.new \
+      nil, from_name, from_version, remote, Gem::Platform::RUBY
+    activation = Gem::Resolver::ActivationRequest.new spec, parent
+
+    Gem::Resolver::DependencyRequest.new dep, activation
+  end
+
+  ##
+  # Constructs a new Gem::Requirement.
+
+  def req(*requirements)
+    return requirements.first if Gem::Requirement === requirements.first
+    Gem::Requirement.create requirements
+  end
+
+  ##
+  # Constructs a new Gem::Specification.
+
+  def spec(name, version, &block)
+    Gem::Specification.new name, v(version), &block
+  end
+
+  ##
+  # Creates a SpecFetcher pre-filled with the gems or specs defined in the
+  # block.
+  #
+  # Yields a +fetcher+ object that responds to +spec+ and +gem+.  +spec+ adds
+  # a specification to the SpecFetcher while +gem+ adds both a specification
+  # and the gem data to the RemoteFetcher so the built gem can be downloaded.
+  #
+  # If only the a-3 gem is supposed to be downloaded you can save setup
+  # time by creating only specs for the other versions:
+  #
+  #   spec_fetcher do |fetcher|
+  #     fetcher.spec 'a', 1
+  #     fetcher.spec 'a', 2, 'b' => 3 # dependency on b = 3
+  #     fetcher.gem 'a', 3 do |spec|
+  #       # spec is a Gem::Specification
+  #       # ...
+  #     end
+  #   end
+
+  def spec_fetcher(repository = @gem_repo)
+    Gem::TestCase::SpecFetcherSetup.declare self, repository do |spec_fetcher_setup|
+      yield spec_fetcher_setup if block_given?
+    end
+  end
+
+  ##
+  # Construct a new Gem::Version.
+
+  def v(string)
+    Gem::Version.create string
+  end
+
+  ##
+  # A vendor_gem is used with a gem dependencies file.  The gem created here
+  # has no files, just a gem specification for the given +name+ and +version+.
+  #
+  # Yields the +specification+ to the block, if given
+
+  def vendor_gem(name = 'a', version = 1)
+    directory = File.join 'vendor', name
+
+    FileUtils.mkdir_p directory
+
+    save_gemspec name, version, directory
+  end
+
+  ##
+  # create_gemspec creates gem specification in given +directory+ or '.'
+  # for the given +name+ and +version+.
+  #
+  # Yields the +specification+ to the block, if given
+
+  def save_gemspec(name = 'a', version = 1, directory = '.')
+    vendor_spec = Gem::Specification.new name, version do |specification|
+      yield specification if block_given?
+    end
+
+    File.open File.join(directory, "#{name}.gemspec"), 'w' do |io|
+      io.write vendor_spec.to_ruby
+    end
+
+    return name, vendor_spec.version, directory
+  end
+
+  ##
+  # The StaticSet is a static set of gem specifications used for testing only.
+  # It is available by requiring Gem::TestCase.
+
+  class StaticSet < Gem::Resolver::Set
+    ##
+    # A StaticSet ignores remote because it has a fixed set of gems.
+
+    attr_accessor :remote
+
+    ##
+    # Creates a new StaticSet for the given +specs+
+
+    def initialize(specs)
+      super()
+
+      @specs = specs
+
+      @remote = true
+    end
+
+    ##
+    # Adds +spec+ to this set.
+
+    def add(spec)
+      @specs << spec
+    end
+
+    ##
+    # Finds +dep+ in this set.
+
+    def find_spec(dep)
+      @specs.reverse_each do |s|
+        return s if dep.matches_spec? s
+      end
+    end
+
+    ##
+    # Finds all gems matching +dep+ in this set.
+
+    def find_all(dep)
+      @specs.find_all {|s| dep.match? s, @prerelease }
+    end
+
+    ##
+    # Loads a Gem::Specification from this set which has the given +name+,
+    # version +ver+, +platform+.  The +source+ is ignored.
+
+    def load_spec(name, ver, platform, source)
+      dep = Gem::Dependency.new name, ver
+      spec = find_spec dep
+
+      Gem::Specification.new spec.name, spec.version do |s|
+        s.platform = spec.platform
+      end
+    end
+
+    def prefetch(reqs) # :nodoc:
+    end
+  end
+
+  ##
+  # Loads certificate named +cert_name+ from <tt>test/rubygems/</tt>.
+
+  def self.load_cert(cert_name)
+    cert_file = cert_path cert_name
+
+    cert = File.read cert_file
+
+    OpenSSL::X509::Certificate.new cert
+  end
+
+  ##
+  # Returns the path to the certificate named +cert_name+ from
+  # <tt>test/rubygems/</tt>.
+
+  def self.cert_path(cert_name)
+    if 32 == (Time.at(2**32) rescue 32)
+      cert_file = "#{TEST_PATH}/#{cert_name}_cert_32.pem"
+
+      return cert_file if File.exist? cert_file
+    end
+
+    "#{TEST_PATH}/#{cert_name}_cert.pem"
+  end
+
+  ##
+  # Loads an RSA private key named +key_name+ with +passphrase+ in <tt>test/rubygems/</tt>
+
+  def self.load_key(key_name, passphrase = nil)
+    key_file = key_path key_name
+
+    key = File.read key_file
+
+    OpenSSL::PKey::RSA.new key, passphrase
+  end
+
+  ##
+  # Returns the path to the key named +key_name+ from <tt>test/rubygems</tt>
+
+  def self.key_path(key_name)
+    "#{TEST_PATH}/#{key_name}_key.pem"
+  end
+
+  # :stopdoc:
+  # only available in RubyGems tests
+
+  PRIVATE_KEY_PASSPHRASE = 'Foo bar'.freeze
+
+  begin
+    PRIVATE_KEY                 = load_key 'private'
+    PRIVATE_KEY_PATH            = key_path 'private'
+
+    # ENCRYPTED_PRIVATE_KEY is PRIVATE_KEY encrypted with PRIVATE_KEY_PASSPHRASE
+    ENCRYPTED_PRIVATE_KEY       = load_key 'encrypted_private', PRIVATE_KEY_PASSPHRASE
+    ENCRYPTED_PRIVATE_KEY_PATH  = key_path 'encrypted_private'
+
+    PUBLIC_KEY                  = PRIVATE_KEY.public_key
+
+    PUBLIC_CERT                 = load_cert 'public'
+    PUBLIC_CERT_PATH            = cert_path 'public'
+  rescue Errno::ENOENT
+    PRIVATE_KEY = nil
+    PUBLIC_KEY  = nil
+    PUBLIC_CERT = nil
+  end if Gem::HAVE_OPENSSL
+end
+
+# https://github.com/seattlerb/minitest/blob/13c48a03d84a2a87855a4de0c959f96800100357/lib/minitest/mock.rb#L192
+class Object
+  def stub(name, val_or_callable, *block_args)
+    new_name = "__minitest_stub__#{name}"
+
+    metaclass = class << self; self; end
+
+    if respond_to? name and not methods.map(&:to_s).include? name.to_s
+      metaclass.send :define_method, name do |*args|
+        super(*args)
+      end
+    end
+
+    metaclass.send :alias_method, new_name, name
+
+    metaclass.send :define_method, name do |*args, &blk|
+      if val_or_callable.respond_to? :call
+        val_or_callable.call(*args, &blk)
+      else
+        blk.call(*block_args) if blk
+        val_or_callable
+      end
+    end
+
+    metaclass.send(:ruby2_keywords, name) if metaclass.respond_to?(:ruby2_keywords, true)
+
+    yield self
+  ensure
+    metaclass.send :undef_method, name
+    metaclass.send :alias_method, name, new_name
+    metaclass.send :undef_method, new_name
+  end
+end
+
+require 'rubygems/test_utilities'
diff --git a/test/rubygems/test_utilities.rb b/test/rubygems/test_utilities.rb
new file mode 100644
index 0000000000..08faef6578
--- /dev/null
+++ b/test/rubygems/test_utilities.rb
@@ -0,0 +1,373 @@
+# frozen_string_literal: true
+require 'tempfile'
+require 'rubygems'
+require 'rubygems/remote_fetcher'
+
+##
+# A fake Gem::RemoteFetcher for use in tests or to avoid real live HTTP
+# requests when testing code that uses RubyGems.
+#
+# Example:
+#
+#   @fetcher = Gem::FakeFetcher.new
+#   @fetcher.data['http://gems.example.com/yaml'] = source_index.to_yaml
+#   Gem::RemoteFetcher.fetcher = @fetcher
+#
+#   use nested array if multiple response is needed
+#
+#   @fetcher.data['http://gems.example.com/sequence'] = [['Success', 200, 'OK'], ['Failed', 401, 'Unauthorized']]
+#
+#   @fetcher.fetch_path('http://gems.example.com/sequence') # => ['Success', 200, 'OK']
+#   @fetcher.fetch_path('http://gems.example.com/sequence') # => ['Failed', 401, 'Unauthorized']
+#
+#   # invoke RubyGems code
+#
+#   paths = @fetcher.paths
+#   assert_equal 'http://gems.example.com/yaml', paths.shift
+#   assert paths.empty?, paths.join(', ')
+#
+# See RubyGems' tests for more examples of FakeFetcher.
+
+class Gem::FakeFetcher
+  attr_reader :data
+  attr_reader :last_request
+  attr_accessor :paths
+
+  def initialize
+    @data = {}
+    @paths = []
+  end
+
+  def find_data(path)
+    return Gem.read_binary path.path if URI === path and 'file' == path.scheme
+
+    if URI === path and "URI::#{path.scheme.upcase}" != path.class.name
+      raise ArgumentError,
+        "mismatch for scheme #{path.scheme} and class #{path.class}"
+    end
+
+    path = path.to_s
+    @paths << path
+    raise ArgumentError, 'need full URI' unless path.start_with?("https://", "http://")
+
+    unless @data.key? path
+      raise Gem::RemoteFetcher::FetchError.new("no data for #{path}", path)
+    end
+
+    if @data[path].kind_of?(Array) && @data[path].first.kind_of?(Array)
+      @data[path].shift
+    else
+      @data[path]
+    end
+  end
+
+  def fetch_path(path, mtime = nil, head = false)
+    data = find_data(path)
+
+    if data.respond_to?(:call)
+      data.call
+    else
+      if path.to_s.end_with?(".gz") and not data.nil? and not data.empty?
+        data = Gem::Util.gunzip data
+      end
+      data
+    end
+  end
+
+  def cache_update_path(uri, path = nil, update = true)
+    if data = fetch_path(uri)
+      File.open(path, 'wb') {|io| io.write data } if path and update
+      data
+    else
+      Gem.read_binary(path) if path
+    end
+  end
+
+  # Thanks, FakeWeb!
+  def open_uri_or_path(path)
+    data = find_data(path)
+    body, code, msg = data
+
+    response = Net::HTTPResponse.send(:response_class, code.to_s).new("1.0", code.to_s, msg)
+    response.instance_variable_set(:@body, body)
+    response.instance_variable_set(:@read, true)
+    response
+  end
+
+  def request(uri, request_class, last_modified = nil)
+    data = find_data(uri)
+    body, code, msg = (data.respond_to?(:call) ? data.call : data)
+
+    @last_request = request_class.new uri.request_uri
+    yield @last_request if block_given?
+
+    response = Net::HTTPResponse.send(:response_class, code.to_s).new("1.0", code.to_s, msg)
+    response.instance_variable_set(:@body, body)
+    response.instance_variable_set(:@read, true)
+    response
+  end
+
+  def pretty_print(q) # :nodoc:
+    q.group 2, '[FakeFetcher', ']' do
+      q.breakable
+      q.text 'URIs:'
+
+      q.breakable
+      q.pp @data.keys
+    end
+  end
+
+  def fetch_size(path)
+    path = path.to_s
+    @paths << path
+
+    raise ArgumentError, 'need full URI' unless path =~ %r{^http://}
+
+    unless @data.key? path
+      raise Gem::RemoteFetcher::FetchError.new("no data for #{path}", path)
+    end
+
+    data = @data[path]
+
+    data.respond_to?(:call) ? data.call : data.length
+  end
+
+  def download(spec, source_uri, install_dir = Gem.dir)
+    name = File.basename spec.cache_file
+    path = if Dir.pwd == install_dir # see fetch_command
+             install_dir
+           else
+             File.join install_dir, "cache"
+           end
+
+    path = File.join path, name
+
+    if source_uri =~ /^http/
+      File.open(path, "wb") do |f|
+        f.write fetch_path(File.join(source_uri, "gems", name))
+      end
+    else
+      FileUtils.cp source_uri, path
+    end
+
+    path
+  end
+
+  def download_to_cache(dependency)
+    found, _ = Gem::SpecFetcher.fetcher.spec_for_dependency dependency
+
+    return if found.empty?
+
+    spec, source = found.first
+
+    download spec, source.uri.to_s
+  end
+end
+
+# :stopdoc:
+class Gem::RemoteFetcher
+  def self.fetcher=(fetcher)
+    @fetcher = fetcher
+  end
+end
+# :startdoc:
+
+##
+# The SpecFetcherSetup allows easy setup of a remote source in RubyGems tests:
+#
+#   spec_fetcher do |f|
+#     f.gem  'a', 1
+#     f.spec 'a', 2
+#     f.gem  'b', 1' 'a' => '~> 1.0'
+#   end
+#
+# The above declaration creates two gems, a-1 and b-1, with a dependency from
+# b to a.  The declaration creates an additional spec a-2, but no gem for it
+# (so it cannot be installed).
+#
+# After the gems are created they are removed from Gem.dir.
+
+class Gem::TestCase::SpecFetcherSetup
+  ##
+  # Executes a SpecFetcher setup block.  Yields an instance then creates the
+  # gems and specifications defined in the instance.
+
+  def self.declare(test, repository)
+    setup = new test, repository
+
+    yield setup
+
+    setup.execute
+  end
+
+  def initialize(test, repository) # :nodoc:
+    @test       = test
+    @repository = repository
+
+    @gems       = {}
+    @downloaded = []
+    @installed  = []
+    @operations = []
+  end
+
+  ##
+  # Returns a Hash of created Specification full names and the corresponding
+  # Specification.
+
+  def created_specs
+    created = {}
+
+    @gems.keys.each do |spec|
+      created[spec.full_name] = spec
+    end
+
+    created
+  end
+
+  ##
+  # Creates any defined gems or specifications
+
+  def execute # :nodoc:
+    execute_operations
+
+    setup_fetcher
+
+    created_specs
+  end
+
+  def execute_operations # :nodoc:
+    @operations.each do |operation, *arguments|
+      block = arguments.pop
+      case operation
+      when :gem then
+        spec, gem = @test.util_gem(*arguments, &block)
+
+        write_spec spec
+
+        @gems[spec] = gem
+        @installed << spec
+      when :download then
+        spec, gem = @test.util_gem(*arguments, &block)
+
+        @gems[spec] = gem
+        @downloaded << spec
+      when :spec then
+        spec = @test.util_spec(*arguments, &block)
+
+        write_spec spec
+
+        @gems[spec] = nil
+        @installed << spec
+      end
+    end
+  end
+
+  ##
+  # Creates a gem with +name+, +version+ and +deps+.  The created gem can be
+  # downloaded and installed.
+  #
+  # The specification will be yielded before gem creation for customization,
+  # but only the block or the dependencies may be set, not both.
+
+  def gem(name, version, dependencies = nil, &block)
+    @operations << [:gem, name, version, dependencies, block]
+  end
+
+  ##
+  # Creates a gem with +name+, +version+ and +deps+.  The created gem is
+  # downloaded in to the cache directory but is not installed
+  #
+  # The specification will be yielded before gem creation for customization,
+  # but only the block or the dependencies may be set, not both.
+
+  def download(name, version, dependencies = nil, &block)
+    @operations << [:download, name, version, dependencies, block]
+  end
+
+  ##
+  # Creates a legacy platform spec with the name 'pl' and version 1
+
+  def legacy_platform
+    spec 'pl', 1 do |s|
+      s.platform = Gem::Platform.new 'i386-linux'
+      s.instance_variable_set :@original_platform, 'i386-linux'
+    end
+  end
+
+  def setup_fetcher # :nodoc:
+    require 'zlib'
+    require 'socket'
+    require 'rubygems/remote_fetcher'
+
+    unless @test.fetcher
+      @test.fetcher = Gem::FakeFetcher.new
+      Gem::RemoteFetcher.fetcher = @test.fetcher
+    end
+
+    Gem::Specification.reset
+
+    begin
+      gem_repo, @test.gem_repo = @test.gem_repo, @repository
+      @test.uri = URI @repository
+
+      @test.util_setup_spec_fetcher(*@downloaded)
+    ensure
+      @test.gem_repo = gem_repo
+      @test.uri = URI gem_repo
+    end
+
+    @gems.each do |spec, gem|
+      next unless gem
+
+      @test.fetcher.data["#{@repository}gems/#{spec.file_name}"] =
+        Gem.read_binary(gem)
+
+      FileUtils.cp gem, spec.cache_file
+    end
+  end
+
+  ##
+  # Creates a spec with +name+, +version+ and +deps+.  The created gem can be
+  # downloaded and installed.
+  #
+  # The specification will be yielded before creation for customization,
+  # but only the block or the dependencies may be set, not both.
+
+  def spec(name, version, dependencies = nil, &block)
+    @operations << [:spec, name, version, dependencies, block]
+  end
+
+  def write_spec(spec) # :nodoc:
+    File.open spec.spec_file, 'w' do |io|
+      io.write spec.to_ruby_for_cache
+    end
+  end
+end
+
+##
+# A StringIO duck-typed class that uses Tempfile instead of String as the
+# backing store.
+#
+# This is available when rubygems/test_utilities is required.
+#--
+# This class was added to flush out problems in Rubinius' IO implementation.
+
+class TempIO < Tempfile
+  ##
+  # Creates a new TempIO that will be initialized to contain +string+.
+
+  def initialize(string = '')
+    super "TempIO"
+    binmode
+    write string
+    rewind
+  end
+
+  ##
+  # The content of the TempIO as a String.
+
+  def string
+    flush
+    Gem.read_binary path
+  end
+end