Move to tool/lib from test/lib.

21 files changed, 6039 insertions, 0 deletions

diff --git a/tool/colors b/tool/colors
new file mode 100644
index 0000000000..a65c326ade
--- /dev/null
+++ b/tool/colors
@@ -0,0 +1,3 @@
+pass=36;7
+fail=31;1;7
+skip=33;1
diff --git a/tool/lib/-test-/integer.rb b/tool/lib/-test-/integer.rb
new file mode 100644
index 0000000000..a224148f24
--- /dev/null
+++ b/tool/lib/-test-/integer.rb
@@ -0,0 +1,14 @@
+require 'test/unit'
+require '-test-/integer.so'
+
+module Test::Unit::Assertions
+  def assert_fixnum(v, msg=nil)
+    assert_instance_of(Integer, v, msg)
+    assert_predicate(v, :fixnum?, msg)
+  end
+
+  def assert_bignum(v, msg=nil)
+    assert_instance_of(Integer, v, msg)
+    assert_predicate(v, :bignum?, msg)
+  end
+end
diff --git a/tool/lib/envutil.rb b/tool/lib/envutil.rb
new file mode 100644
index 0000000000..b4eb63da90
--- /dev/null
+++ b/tool/lib/envutil.rb
@@ -0,0 +1,311 @@
+# -*- coding: us-ascii -*-
+# frozen_string_literal: true
+require "open3"
+require "timeout"
+require_relative "find_executable"
+begin
+  require 'rbconfig'
+rescue LoadError
+end
+begin
+  require "rbconfig/sizeof"
+rescue LoadError
+end
+
+module EnvUtil
+  def rubybin
+    if ruby = ENV["RUBY"]
+      return ruby
+    end
+    ruby = "ruby"
+    exeext = RbConfig::CONFIG["EXEEXT"]
+    rubyexe = (ruby + exeext if exeext and !exeext.empty?)
+    3.times do
+      if File.exist? ruby and File.executable? ruby and !File.directory? ruby
+        return File.expand_path(ruby)
+      end
+      if rubyexe and File.exist? rubyexe and File.executable? rubyexe
+        return File.expand_path(rubyexe)
+      end
+      ruby = File.join("..", ruby)
+    end
+    if defined?(RbConfig.ruby)
+      RbConfig.ruby
+    else
+      "ruby"
+    end
+  end
+  module_function :rubybin
+
+  LANG_ENVS = %w"LANG LC_ALL LC_CTYPE"
+
+  DEFAULT_SIGNALS = Signal.list
+  DEFAULT_SIGNALS.delete("TERM") if /mswin|mingw/ =~ RUBY_PLATFORM
+
+  RUBYLIB = ENV["RUBYLIB"]
+
+  class << self
+    attr_accessor :timeout_scale
+    attr_reader :original_internal_encoding, :original_external_encoding,
+                :original_verbose
+
+    def capture_global_values
+      @original_internal_encoding = Encoding.default_internal
+      @original_external_encoding = Encoding.default_external
+      @original_verbose = $VERBOSE
+    end
+  end
+
+  def apply_timeout_scale(t)
+    if scale = EnvUtil.timeout_scale
+      t * scale
+    else
+      t
+    end
+  end
+  module_function :apply_timeout_scale
+
+  def timeout(sec, klass = nil, message = nil, &blk)
+    return yield(sec) if sec == nil or sec.zero?
+    sec = apply_timeout_scale(sec)
+    Timeout.timeout(sec, klass, message, &blk)
+  end
+  module_function :timeout
+
+  def terminate(pid, signal = :TERM, pgroup = nil, reprieve = 1)
+    reprieve = apply_timeout_scale(reprieve) if reprieve
+
+    signals = Array(signal).select do |sig|
+      DEFAULT_SIGNALS[sig.to_s] or
+        DEFAULT_SIGNALS[Signal.signame(sig)] rescue false
+    end
+    signals |= [:ABRT, :KILL]
+    case pgroup
+    when 0, true
+      pgroup = -pid
+    when nil, false
+      pgroup = pid
+    end
+    while signal = signals.shift
+      begin
+        Process.kill signal, pgroup
+      rescue Errno::EINVAL
+        next
+      rescue Errno::ESRCH
+        break
+      end
+      if signals.empty? or !reprieve
+        Process.wait(pid)
+      else
+        begin
+          Timeout.timeout(reprieve) {Process.wait(pid)}
+        rescue Timeout::Error
+        end
+      end
+    end
+    $?
+  end
+  module_function :terminate
+
+  def invoke_ruby(args, stdin_data = "", capture_stdout = false, capture_stderr = false,
+                  encoding: nil, timeout: 10, reprieve: 1, timeout_error: Timeout::Error,
+                  stdout_filter: nil, stderr_filter: nil,
+                  signal: :TERM,
+                  rubybin: EnvUtil.rubybin, precommand: nil,
+                  **opt)
+    timeout = apply_timeout_scale(timeout)
+
+    in_c, in_p = IO.pipe
+    out_p, out_c = IO.pipe if capture_stdout
+    err_p, err_c = IO.pipe if capture_stderr && capture_stderr != :merge_to_stdout
+    opt[:in] = in_c
+    opt[:out] = out_c if capture_stdout
+    opt[:err] = capture_stderr == :merge_to_stdout ? out_c : err_c if capture_stderr
+    if encoding
+      out_p.set_encoding(encoding) if out_p
+      err_p.set_encoding(encoding) if err_p
+    end
+    c = "C"
+    child_env = {}
+    LANG_ENVS.each {|lc| child_env[lc] = c}
+    if Array === args and Hash === args.first
+      child_env.update(args.shift)
+    end
+    if RUBYLIB and lib = child_env["RUBYLIB"]
+      child_env["RUBYLIB"] = [lib, RUBYLIB].join(File::PATH_SEPARATOR)
+    end
+    args = [args] if args.kind_of?(String)
+    pid = spawn(child_env, *precommand, rubybin, *args, **opt)
+    in_c.close
+    out_c.close if capture_stdout
+    err_c.close if capture_stderr && capture_stderr != :merge_to_stdout
+    if block_given?
+      return yield in_p, out_p, err_p, pid
+    else
+      th_stdout = Thread.new { out_p.read } if capture_stdout
+      th_stderr = Thread.new { err_p.read } if capture_stderr && capture_stderr != :merge_to_stdout
+      in_p.write stdin_data.to_str unless stdin_data.empty?
+      in_p.close
+      if (!th_stdout || th_stdout.join(timeout)) && (!th_stderr || th_stderr.join(timeout))
+        timeout_error = nil
+      else
+        status = terminate(pid, signal, opt[:pgroup], reprieve)
+      end
+      stdout = th_stdout.value if capture_stdout
+      stderr = th_stderr.value if capture_stderr && capture_stderr != :merge_to_stdout
+      out_p.close if capture_stdout
+      err_p.close if capture_stderr && capture_stderr != :merge_to_stdout
+      status ||= Process.wait2(pid)[1]
+      stdout = stdout_filter.call(stdout) if stdout_filter
+      stderr = stderr_filter.call(stderr) if stderr_filter
+      if timeout_error
+        bt = caller_locations
+        msg = "execution of #{bt.shift.label} expired timeout (#{timeout} sec)"
+        msg = Test::Unit::Assertions::FailDesc[status, msg, [stdout, stderr].join("\n")].()
+        raise timeout_error, msg, bt.map(&:to_s)
+      end
+      return stdout, stderr, status
+    end
+  ensure
+    [th_stdout, th_stderr].each do |th|
+      th.kill if th
+    end
+    [in_c, in_p, out_c, out_p, err_c, err_p].each do |io|
+      io&.close
+    end
+    [th_stdout, th_stderr].each do |th|
+      th.join if th
+    end
+  end
+  module_function :invoke_ruby
+
+  alias rubyexec invoke_ruby
+  class << self
+    alias rubyexec invoke_ruby
+  end
+
+  def verbose_warning
+    class << (stderr = "".dup)
+      alias write concat
+      def flush; end
+    end
+    stderr, $stderr = $stderr, stderr
+    $VERBOSE = true
+    yield stderr
+    return $stderr
+  ensure
+    stderr, $stderr = $stderr, stderr
+    $VERBOSE = EnvUtil.original_verbose
+  end
+  module_function :verbose_warning
+
+  def default_warning
+    $VERBOSE = false
+    yield
+  ensure
+    $VERBOSE = EnvUtil.original_verbose
+  end
+  module_function :default_warning
+
+  def suppress_warning
+    $VERBOSE = nil
+    yield
+  ensure
+    $VERBOSE = EnvUtil.original_verbose
+  end
+  module_function :suppress_warning
+
+  def under_gc_stress(stress = true)
+    stress, GC.stress = GC.stress, stress
+    yield
+  ensure
+    GC.stress = stress
+  end
+  module_function :under_gc_stress
+
+  def with_default_external(enc)
+    suppress_warning { Encoding.default_external = enc }
+    yield
+  ensure
+    suppress_warning { Encoding.default_external = EnvUtil.original_external_encoding }
+  end
+  module_function :with_default_external
+
+  def with_default_internal(enc)
+    suppress_warning { Encoding.default_internal = enc }
+    yield
+  ensure
+    suppress_warning { Encoding.default_internal = EnvUtil.original_internal_encoding }
+  end
+  module_function :with_default_internal
+
+  def labeled_module(name, &block)
+    Module.new do
+      singleton_class.class_eval {define_method(:to_s) {name}; alias inspect to_s}
+      class_eval(&block) if block
+    end
+  end
+  module_function :labeled_module
+
+  def labeled_class(name, superclass = Object, &block)
+    Class.new(superclass) do
+      singleton_class.class_eval {define_method(:to_s) {name}; alias inspect to_s}
+      class_eval(&block) if block
+    end
+  end
+  module_function :labeled_class
+
+  if /darwin/ =~ RUBY_PLATFORM
+    DIAGNOSTIC_REPORTS_PATH = File.expand_path("~/Library/Logs/DiagnosticReports")
+    DIAGNOSTIC_REPORTS_TIMEFORMAT = '%Y-%m-%d-%H%M%S'
+    @ruby_install_name = RbConfig::CONFIG['RUBY_INSTALL_NAME']
+
+    def self.diagnostic_reports(signame, pid, now)
+      return unless %w[ABRT QUIT SEGV ILL TRAP].include?(signame)
+      cmd = File.basename(rubybin)
+      cmd = @ruby_install_name if "ruby-runner#{RbConfig::CONFIG["EXEEXT"]}" == cmd
+      path = DIAGNOSTIC_REPORTS_PATH
+      timeformat = DIAGNOSTIC_REPORTS_TIMEFORMAT
+      pat = "#{path}/#{cmd}_#{now.strftime(timeformat)}[-_]*.crash"
+      first = true
+      30.times do
+        first ? (first = false) : sleep(0.1)
+        Dir.glob(pat) do |name|
+          log = File.read(name) rescue next
+          if /\AProcess:\s+#{cmd} \[#{pid}\]$/ =~ log
+            File.unlink(name)
+            File.unlink("#{path}/.#{File.basename(name)}.plist") rescue nil
+            return log
+          end
+        end
+      end
+      nil
+    end
+  else
+    def self.diagnostic_reports(signame, pid, now)
+    end
+  end
+
+  def self.gc_stress_to_class?
+    unless defined?(@gc_stress_to_class)
+      _, _, status = invoke_ruby(["-e""exit GC.respond_to?(:add_stress_to_class)"])
+      @gc_stress_to_class = status.success?
+    end
+    @gc_stress_to_class
+  end
+end
+
+if defined?(RbConfig)
+  module RbConfig
+    @ruby = EnvUtil.rubybin
+    class << self
+      undef ruby if method_defined?(:ruby)
+      attr_reader :ruby
+    end
+    dir = File.dirname(ruby)
+    CONFIG['bindir'] = dir
+    Gem::ConfigMap[:bindir] = dir if defined?(Gem::ConfigMap)
+  end
+end
+
+EnvUtil.capture_global_values
diff --git a/tool/lib/find_executable.rb b/tool/lib/find_executable.rb
new file mode 100644
index 0000000000..89c6fb8f3b
--- /dev/null
+++ b/tool/lib/find_executable.rb
@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+require "rbconfig"
+
+module EnvUtil
+  def find_executable(cmd, *args)
+    exts = RbConfig::CONFIG["EXECUTABLE_EXTS"].split | [RbConfig::CONFIG["EXEEXT"]]
+    ENV["PATH"].split(File::PATH_SEPARATOR).each do |path|
+      next if path.empty?
+      path = File.join(path, cmd)
+      exts.each do |ext|
+        cmdline = [path + ext, *args]
+        begin
+          return cmdline if yield(IO.popen(cmdline, "r", err: [:child, :out], &:read))
+        rescue
+          next
+        end
+      end
+    end
+    nil
+  end
+  module_function :find_executable
+end
diff --git a/tool/lib/iseq_loader_checker.rb b/tool/lib/iseq_loader_checker.rb
new file mode 100644
index 0000000000..1a1a694834
--- /dev/null
+++ b/tool/lib/iseq_loader_checker.rb
@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+begin
+  require '-test-/iseq_load/iseq_load'
+rescue LoadError
+end
+require 'tempfile'
+
+class RubyVM::InstructionSequence
+  def disasm_if_possible
+    begin
+      self.disasm
+    rescue Encoding::CompatibilityError, EncodingError, SecurityError
+      nil
+    end
+  end
+
+  def self.compare_dump_and_load i1, dumper, loader
+    dump = dumper.call(i1)
+    return i1 unless dump
+    i2 = loader.call(dump)
+
+    # compare disassembled result
+    d1 = i1.disasm_if_possible
+    d2 = i2.disasm_if_possible
+
+    if d1 != d2
+      STDERR.puts "expected:"
+      STDERR.puts d1
+      STDERR.puts "actual:"
+      STDERR.puts d2
+
+      t1 = Tempfile.new("expected"); t1.puts d1; t1.close
+      t2 = Tempfile.new("actual"); t2.puts d2; t2.close
+      system("diff -u #{t1.path} #{t2.path}") # use diff if available
+      exit(1)
+    end
+    i2
+  end
+
+  CHECK_TO_A      = ENV['RUBY_ISEQ_DUMP_DEBUG'] == 'to_a'
+  CHECK_TO_BINARY = ENV['RUBY_ISEQ_DUMP_DEBUG'] == 'to_binary'
+
+  def self.translate i1
+    # check to_a/load_iseq
+    compare_dump_and_load(i1,
+                                   proc{|iseq|
+                                     ary = iseq.to_a
+                                     ary[9] == :top ? ary : nil
+                                   },
+                                   proc{|ary|
+                                     RubyVM::InstructionSequence.iseq_load(ary)
+                                   }) if CHECK_TO_A && defined?(RubyVM::InstructionSequence.iseq_load)
+
+    # check to_binary
+    i2_bin = compare_dump_and_load(i1,
+                                   proc{|iseq|
+                                     begin
+                                       iseq.to_binary
+                                     rescue RuntimeError # not a toplevel
+                                       # STDERR.puts [:failed, $!, iseq].inspect
+                                       nil
+                                     end
+                                   },
+                                   proc{|bin|
+                                     iseq = RubyVM::InstructionSequence.load_from_binary(bin)
+                                     # STDERR.puts iseq.inspect
+                                     iseq
+                                   }) if CHECK_TO_BINARY
+    # return value
+    i2_bin if CHECK_TO_BINARY
+  end if CHECK_TO_A || CHECK_TO_BINARY
+end
+
+#require_relative 'x'; exit(1)
diff --git a/tool/lib/jit_support.rb b/tool/lib/jit_support.rb
new file mode 100644
index 0000000000..c1624cc3b2
--- /dev/null
+++ b/tool/lib/jit_support.rb
@@ -0,0 +1,68 @@
+require 'rbconfig'
+
+module JITSupport
+  JIT_TIMEOUT = 600 # 10min for each...
+  JIT_SUCCESS_PREFIX = 'JIT success \(\d+\.\dms\)'
+  UNSUPPORTED_COMPILERS = [
+    %r[\Aicc\b],
+    %r[\A/opt/developerstudio\d+\.\d+/bin/cc\z],
+  ]
+
+  module_function
+  # Run Ruby script with --jit-wait (Synchronous JIT compilation).
+  # Returns [stdout, stderr]
+  def eval_with_jit(env = nil, script, **opts)
+    stdout, stderr = nil, nil
+    # retry 3 times while cc1 error happens.
+    3.times do |i|
+      stdout, stderr, status = eval_with_jit_without_retry(env, script, **opts)
+      assert_equal(true, status.success?, "Failed to run script with JIT:\n#{code_block(script)}\nstdout:\n#{code_block(stdout)}\nstderr:\n#{code_block(stderr)}")
+      break unless retried_stderr?(stderr)
+    end
+    [stdout, stderr]
+  end
+
+  def eval_with_jit_without_retry(env = nil, script, verbose: 0, min_calls: 5, save_temps: false, max_cache: 1000, wait: true, timeout: JIT_TIMEOUT)
+    args = [
+      '--disable-gems', "--jit-verbose=#{verbose}",
+      "--jit-min-calls=#{min_calls}", "--jit-max-cache=#{max_cache}",
+    ]
+    args << '--jit-wait' if wait
+    args << '--jit-save-temps' if save_temps
+    args << '-e' << script
+    base_env = { 'MJIT_SEARCH_BUILD_DIR' => 'true' } # workaround to skip requiring `make install` for `make test-all`
+    if preloadenv = RbConfig::CONFIG['PRELOADENV'] and !preloadenv.empty?
+      so = "mjit_build_dir.#{RbConfig::CONFIG['SOEXT']}"
+      base_env[preloadenv] = File.realpath(so) rescue nil
+    end
+    args.unshift(env ? base_env.merge!(env) : base_env)
+    EnvUtil.invoke_ruby(args,
+      '', true, true, timeout: timeout,
+    )
+  end
+
+  def supported?
+    return @supported if defined?(@supported)
+    @supported = UNSUPPORTED_COMPILERS.all? do |regexp|
+      !regexp.match?(RbConfig::CONFIG['CC'])
+    end
+  end
+
+  def remove_mjit_logs(stderr)
+    if RubyVM::MJIT.enabled? # utility for -DFORCE_MJIT_ENABLE
+      stderr.gsub(/^MJIT warning: Skipped to compile unsupported instruction: \w+\n/m, '')
+    else
+      stderr
+    end
+  end
+
+  def code_block(code)
+    %Q["""\n#{code}\n"""\n\n]
+  end
+
+  # We're retrying cc1 not found error on gcc, which should be solved in the future but ignored for now.
+  def retried_stderr?(stderr)
+    RbConfig::CONFIG['CC'].start_with?('gcc') &&
+      stderr.include?("error trying to exec 'cc1': execvp: No such file or directory")
+  end
+end
diff --git a/tool/lib/leakchecker.rb b/tool/lib/leakchecker.rb
new file mode 100644
index 0000000000..af9200bf77
--- /dev/null
+++ b/tool/lib/leakchecker.rb
@@ -0,0 +1,240 @@
+# frozen_string_literal: true
+class LeakChecker
+  def initialize
+    @fd_info = find_fds
+    @tempfile_info = find_tempfiles
+    @thread_info = find_threads
+    @env_info = find_env
+    @encoding_info = find_encodings
+    @old_verbose = $VERBOSE
+  end
+
+  def check(test_name)
+    leaks = [
+      check_fd_leak(test_name),
+      check_thread_leak(test_name),
+      check_tempfile_leak(test_name),
+      check_env(test_name),
+      check_encodings(test_name),
+      check_safe(test_name),
+      check_verbose(test_name),
+    ]
+    GC.start if leaks.any?
+  end
+
+  def check_safe test_name
+    puts "#{test_name}: $SAFE == #{$SAFE}" unless $SAFE == 0
+  end
+
+  def check_verbose test_name
+    puts "#{test_name}: $VERBOSE == #{$VERBOSE}" unless @old_verbose == $VERBOSE
+  end
+
+  def find_fds
+    if IO.respond_to?(:console) and (m = IO.method(:console)).arity.nonzero?
+      m[:close]
+    end
+    fd_dir = "/proc/self/fd"
+    if File.directory?(fd_dir)
+      fds = Dir.open(fd_dir) {|d|
+        a = d.grep(/\A\d+\z/, &:to_i)
+        if d.respond_to? :fileno
+          a -= [d.fileno]
+        end
+        a
+      }
+      fds.sort
+    else
+      []
+    end
+  end
+
+  def check_fd_leak(test_name)
+    leaked = false
+    live1 = @fd_info
+    live2 = find_fds
+    fd_closed = live1 - live2
+    if !fd_closed.empty?
+      fd_closed.each {|fd|
+        puts "Closed file descriptor: #{test_name}: #{fd}"
+      }
+    end
+    fd_leaked = live2 - live1
+    if !fd_leaked.empty?
+      leaked = true
+      h = {}
+      ObjectSpace.each_object(IO) {|io|
+        inspect = io.inspect
+        begin
+          autoclose = io.autoclose?
+          fd = io.fileno
+        rescue IOError # closed IO object
+          next
+        end
+        (h[fd] ||= []) << [io, autoclose, inspect]
+      }
+      fd_leaked.each {|fd|
+        str = ''.dup
+        if h[fd]
+          str << ' :'
+          h[fd].map {|io, autoclose, inspect|
+            s = ' ' + inspect
+            s << "(not-autoclose)" if !autoclose
+            s
+          }.sort.each {|s|
+            str << s
+          }
+        end
+        puts "Leaked file descriptor: #{test_name}: #{fd}#{str}"
+      }
+      #system("lsof -p #$$") if !fd_leaked.empty?
+      h.each {|fd, list|
+        next if list.length <= 1
+        if 1 < list.count {|io, autoclose, inspect| autoclose }
+          str = list.map {|io, autoclose, inspect| " #{inspect}" + (autoclose ? "(autoclose)" : "") }.sort.join
+          puts "Multiple autoclose IO object for a file descriptor:#{str}"
+        end
+      }
+    end
+    @fd_info = live2
+    return leaked
+  end
+
+  def extend_tempfile_counter
+    return if defined? LeakChecker::TempfileCounter
+    m = Module.new {
+      @count = 0
+      class << self
+        attr_accessor :count
+      end
+
+      def new(data)
+        LeakChecker::TempfileCounter.count += 1
+        super(data)
+      end
+    }
+    LeakChecker.const_set(:TempfileCounter, m)
+
+    class << Tempfile::Remover
+      prepend LeakChecker::TempfileCounter
+    end
+  end
+
+  def find_tempfiles(prev_count=-1)
+    return [prev_count, []] unless defined? Tempfile
+    extend_tempfile_counter
+    count = TempfileCounter.count
+    if prev_count == count
+      [prev_count, []]
+    else
+      tempfiles = ObjectSpace.each_object(Tempfile).find_all {|t|
+        t.instance_variable_defined?(:@tmpfile) and t.path
+      }
+      [count, tempfiles]
+    end
+  end
+
+  def check_tempfile_leak(test_name)
+    return false unless defined? Tempfile
+    count1, initial_tempfiles = @tempfile_info
+    count2, current_tempfiles = find_tempfiles(count1)
+    leaked = false
+    tempfiles_leaked = current_tempfiles - initial_tempfiles
+    if !tempfiles_leaked.empty?
+      leaked = true
+      list = tempfiles_leaked.map {|t| t.inspect }.sort
+      list.each {|str|
+        puts "Leaked tempfile: #{test_name}: #{str}"
+      }
+      tempfiles_leaked.each {|t| t.close! }
+    end
+    @tempfile_info = [count2, initial_tempfiles]
+    return leaked
+  end
+
+  def find_threads
+    Thread.list.find_all {|t|
+      t != Thread.current && t.alive?
+    }
+  end
+
+  def check_thread_leak(test_name)
+    live1 = @thread_info
+    live2 = find_threads
+    thread_finished = live1 - live2
+    leaked = false
+    if !thread_finished.empty?
+      list = thread_finished.map {|t| t.inspect }.sort
+      list.each {|str|
+        puts "Finished thread: #{test_name}: #{str}"
+      }
+    end
+    thread_leaked = live2 - live1
+    if !thread_leaked.empty?
+      leaked = true
+      list = thread_leaked.map {|t| t.inspect }.sort
+      list.each {|str|
+        puts "Leaked thread: #{test_name}: #{str}"
+      }
+    end
+    @thread_info = live2
+    return leaked
+  end
+
+  def find_env
+    ENV.to_h
+  end
+
+  def check_env(test_name)
+    old_env = @env_info
+    new_env = ENV.to_h
+    return false if old_env == new_env
+    (old_env.keys | new_env.keys).sort.each {|k|
+      if old_env.has_key?(k)
+        if new_env.has_key?(k)
+          if old_env[k] != new_env[k]
+            puts "Environment variable changed: #{test_name} : #{k.inspect} changed : #{old_env[k].inspect} -> #{new_env[k].inspect}"
+          end
+        else
+          puts "Environment variable changed: #{test_name} : #{k.inspect} deleted"
+        end
+      else
+        if new_env.has_key?(k)
+          puts "Environment variable changed: #{test_name} : #{k.inspect} added"
+        else
+          flunk "unreachable"
+        end
+      end
+    }
+    @env_info = new_env
+    return true
+  end
+
+  def find_encodings
+    [Encoding.default_internal, Encoding.default_external]
+  end
+
+  def check_encodings(test_name)
+    old_internal, old_external = @encoding_info
+    new_internal, new_external = find_encodings
+    leaked = false
+    if new_internal != old_internal
+      leaked = true
+      puts "Encoding.default_internal changed: #{test_name} : #{old_internal.inspect} to #{new_internal.inspect}"
+    end
+    if new_external != old_external
+      leaked = true
+      puts "Encoding.default_external changed: #{test_name} : #{old_external.inspect} to #{new_external.inspect}"
+    end
+    @encoding_info = [new_internal, new_external]
+    return leaked
+  end
+
+  def puts(*a)
+    output = MiniTest::Unit.output
+    if defined?(output.set_encoding)
+      output.set_encoding(nil, nil)
+    end
+    output.puts(*a)
+  end
+end
diff --git a/tool/lib/memory_status.rb b/tool/lib/memory_status.rb
new file mode 100644
index 0000000000..ad002b2dda
--- /dev/null
+++ b/tool/lib/memory_status.rb
@@ -0,0 +1,149 @@
+# frozen_string_literal: true
+begin
+  require '-test-/memory_status.so'
+rescue LoadError
+end
+
+module Memory
+  keys = []
+
+  case
+  when File.exist?(procfile = "/proc/self/status") && (pat = /^Vm(\w+):\s+(\d+)/) =~ (data = File.binread(procfile))
+    PROC_FILE = procfile
+    VM_PAT = pat
+    def self.read_status
+      IO.foreach(PROC_FILE, encoding: Encoding::ASCII_8BIT) do |l|
+        yield($1.downcase.intern, $2.to_i * 1024) if VM_PAT =~ l
+      end
+    end
+
+    data.scan(pat) {|k, v| keys << k.downcase.intern}
+
+  when /mswin|mingw/ =~ RUBY_PLATFORM
+    require 'fiddle/import'
+    require 'fiddle/types'
+
+    module Win32
+      extend Fiddle::Importer
+      dlload "kernel32.dll", "psapi.dll"
+      include Fiddle::Win32Types
+      typealias "SIZE_T", "size_t"
+
+      PROCESS_MEMORY_COUNTERS = struct [
+        "DWORD  cb",
+        "DWORD  PageFaultCount",
+        "SIZE_T PeakWorkingSetSize",
+        "SIZE_T WorkingSetSize",
+        "SIZE_T QuotaPeakPagedPoolUsage",
+        "SIZE_T QuotaPagedPoolUsage",
+        "SIZE_T QuotaPeakNonPagedPoolUsage",
+        "SIZE_T QuotaNonPagedPoolUsage",
+        "SIZE_T PagefileUsage",
+        "SIZE_T PeakPagefileUsage",
+      ]
+
+      typealias "PPROCESS_MEMORY_COUNTERS", "PROCESS_MEMORY_COUNTERS*"
+
+      extern "HANDLE GetCurrentProcess()", :stdcall
+      extern "BOOL GetProcessMemoryInfo(HANDLE, PPROCESS_MEMORY_COUNTERS, DWORD)", :stdcall
+
+      module_function
+      def memory_info
+        size = PROCESS_MEMORY_COUNTERS.size
+        data = PROCESS_MEMORY_COUNTERS.malloc
+        data.cb = size
+        data if GetProcessMemoryInfo(GetCurrentProcess(), data, size)
+      end
+    end
+
+    keys << :peak << :size
+    def self.read_status
+      if info = Win32.memory_info
+        yield :peak, info.PeakPagefileUsage
+        yield :size, info.PagefileUsage
+      end
+    end
+  when (require_relative 'find_executable'
+        pat = /^\s*(\d+)\s+(\d+)$/
+        pscmd = EnvUtil.find_executable("ps", "-ovsz=", "-orss=", "-p", $$.to_s) {|out| pat =~ out})
+    pscmd.pop
+    PAT = pat
+    PSCMD = pscmd
+
+    keys << :size << :rss
+    def self.read_status
+      if PAT =~ IO.popen(PSCMD + [$$.to_s], "r", err: [:child, :out], &:read)
+        yield :size, $1.to_i*1024
+        yield :rss, $2.to_i*1024
+      end
+    end
+  else
+    def self.read_status
+      raise NotImplementedError, "unsupported platform"
+    end
+  end
+
+  if !keys.empty?
+    Status = Struct.new(*keys)
+  end
+end unless defined?(Memory::Status)
+
+if defined?(Memory::Status)
+  class Memory::Status
+    def _update
+      Memory.read_status do |key, val|
+        self[key] = val
+      end
+    end unless method_defined?(:_update)
+
+    Header = members.map {|k| k.to_s.upcase.rjust(6)}.join('')
+    Format = "%6d"
+
+    def initialize
+      _update
+    end
+
+    def to_s
+      status = each_pair.map {|n,v|
+        "#{n}:#{v}"
+      }
+      "{#{status.join(",")}}"
+    end
+
+    def self.parse(str)
+      status = allocate
+      str.scan(/(?:\A\{|\G,)(#{members.join('|')}):(\d+)(?=,|\}\z)/) do
+        status[$1] = $2.to_i
+      end
+      status
+    end
+  end
+
+  # On some platforms (e.g. Solaris), libc malloc does not return
+  # freed memory to OS because of efficiency, and linking with extra
+  # malloc library is needed to detect memory leaks.
+  #
+  case RUBY_PLATFORM
+  when /solaris2\.(?:9|[1-9][0-9])/i # Solaris 9, 10, 11,...
+    bits = [nil].pack('p').size == 8 ? 64 : 32
+    if ENV['LD_PRELOAD'].to_s.empty? &&
+        ENV["LD_PRELOAD_#{bits}"].to_s.empty? &&
+        (ENV['UMEM_OPTIONS'].to_s.empty? ||
+         ENV['UMEM_OPTIONS'] == 'backend=mmap') then
+      envs = {
+        'LD_PRELOAD' => 'libumem.so',
+        'UMEM_OPTIONS' => 'backend=mmap'
+      }
+      args = [
+              envs,
+              "--disable=gems",
+              "-v", "-",
+             ]
+      _, err, status = EnvUtil.invoke_ruby(args, "exit(0)", true, true)
+      if status.exitstatus == 0 && err.to_s.empty? then
+        Memory::NO_MEMORY_LEAK_ENVS = envs
+      end
+    end
+  end #case RUBY_PLATFORM
+
+end
diff --git a/tool/lib/minitest/README.txt b/tool/lib/minitest/README.txt
new file mode 100644
index 0000000000..368cc3aa4e
--- /dev/null
+++ b/tool/lib/minitest/README.txt
@@ -0,0 +1,457 @@
+= minitest/{unit,spec,mock,benchmark}
+
+home :: https://github.com/seattlerb/minitest
+rdoc :: http://docs.seattlerb.org/minitest
+vim  :: https://github.com/sunaku/vim-ruby-minitest
+
+== DESCRIPTION:
+
+minitest provides a complete suite of testing facilities supporting
+TDD, BDD, mocking, and benchmarking.
+
+    "I had a class with Jim Weirich on testing last week and we were
+     allowed to choose our testing frameworks. Kirk Haines and I were
+     paired up and we cracked open the code for a few test
+     frameworks...
+
+     I MUST say that minitest is *very* readable / understandable
+     compared to the 'other two' options we looked at. Nicely done and
+     thank you for helping us keep our mental sanity."
+
+    -- Wayne E. Seguin
+
+minitest/unit is a small and incredibly fast unit testing framework.
+It provides a rich set of assertions to make your tests clean and
+readable.
+
+minitest/spec is a functionally complete spec engine. It hooks onto
+minitest/unit and seamlessly bridges test assertions over to spec
+expectations.
+
+minitest/benchmark is an awesome way to assert the performance of your
+algorithms in a repeatable manner. Now you can assert that your newb
+co-worker doesn't replace your linear algorithm with an exponential
+one!
+
+minitest/mock by Steven Baker, is a beautifully tiny mock (and stub)
+object framework.
+
+minitest/pride shows pride in testing and adds coloring to your test
+output. I guess it is an example of how to write IO pipes too. :P
+
+minitest/unit is meant to have a clean implementation for language
+implementors that need a minimal set of methods to bootstrap a working
+test suite. For example, there is no magic involved for test-case
+discovery.
+
+    "Again, I can't praise enough the idea of a testing/specing
+     framework that I can actually read in full in one sitting!"
+
+    -- Piotr Szotkowski
+
+Comparing to rspec:
+
+    rspec is a testing DSL. minitest is ruby.
+
+    -- Adam Hawkins, "Bow Before MiniTest"
+
+minitest doesn't reinvent anything that ruby already provides, like:
+classes, modules, inheritance, methods. This means you only have to
+learn ruby to use minitest and all of your regular OO practices like
+extract-method refactorings still apply.
+
+== FEATURES/PROBLEMS:
+
+* minitest/autorun - the easy and explicit way to run all your tests.
+* minitest/unit - a very fast, simple, and clean test system.
+* minitest/spec - a very fast, simple, and clean spec system.
+* minitest/mock - a simple and clean mock/stub system.
+* minitest/benchmark - an awesome way to assert your algorithm's performance.
+* minitest/pride - show your pride in testing!
+* Incredibly small and fast runner, but no bells and whistles.
+
+== RATIONALE:
+
+See design_rationale.rb to see how specs and tests work in minitest.
+
+== SYNOPSIS:
+
+Given that you'd like to test the following class:
+
+  class Meme
+    def i_can_has_cheezburger?
+      "OHAI!"
+    end
+
+    def will_it_blend?
+      "YES!"
+    end
+  end
+
+=== Unit tests
+
+  require 'minitest/autorun'
+
+  class TestMeme < MiniTest::Unit::TestCase
+    def setup
+      @meme = Meme.new
+    end
+
+    def test_that_kitty_can_eat
+      assert_equal "OHAI!", @meme.i_can_has_cheezburger?
+    end
+
+    def test_that_it_will_not_blend
+      refute_match /^no/i, @meme.will_it_blend?
+    end
+
+    def test_that_will_be_skipped
+      skip "test this later"
+    end
+  end
+
+=== Specs
+
+  require 'minitest/autorun'
+
+  describe Meme do
+    before do
+      @meme = Meme.new
+    end
+
+    describe "when asked about cheeseburgers" do
+      it "must respond positively" do
+        @meme.i_can_has_cheezburger?.must_equal "OHAI!"
+      end
+    end
+
+    describe "when asked about blending possibilities" do
+      it "won't say no" do
+        @meme.will_it_blend?.wont_match /^no/i
+      end
+    end
+  end
+
+For matchers support check out:
+
+https://github.com/zenspider/minitest-matchers
+
+=== Benchmarks
+
+Add benchmarks to your regular unit tests. If the unit tests fail, the
+benchmarks won't run.
+
+  # optionally run benchmarks, good for CI-only work!
+  require 'minitest/benchmark' if ENV["BENCH"]
+
+  class TestMeme < MiniTest::Unit::TestCase
+    # Override self.bench_range or default range is [1, 10, 100, 1_000, 10_000]
+    def bench_my_algorithm
+      assert_performance_linear 0.9999 do |n| # n is a range value
+        @obj.my_algorithm(n)
+      end
+    end
+  end
+
+Or add them to your specs. If you make benchmarks optional, you'll
+need to wrap your benchmarks in a conditional since the methods won't
+be defined.
+
+  describe Meme do
+    if ENV["BENCH"] then
+      bench_performance_linear "my_algorithm", 0.9999 do |n|
+        100.times do
+          @obj.my_algorithm(n)
+        end
+      end
+    end
+  end
+
+outputs something like:
+
+  # Running benchmarks:
+
+  TestBlah	100	1000	10000
+  bench_my_algorithm	 0.006167	 0.079279	 0.786993
+  bench_other_algorithm	 0.061679	 0.792797	 7.869932
+
+Output is tab-delimited to make it easy to paste into a spreadsheet.
+
+=== Mocks
+
+  class MemeAsker
+    def initialize(meme)
+      @meme = meme
+    end
+
+    def ask(question)
+      method = question.tr(" ","_") + "?"
+      @meme.__send__(method)
+    end
+  end
+
+  require 'minitest/autorun'
+
+  describe MemeAsker do
+    before do
+      @meme = MiniTest::Mock.new
+      @meme_asker = MemeAsker.new @meme
+    end
+
+    describe "#ask" do
+      describe "when passed an unpunctuated question" do
+        it "should invoke the appropriate predicate method on the meme" do
+          @meme.expect :will_it_blend?, :return_value
+          @meme_asker.ask "will it blend"
+          @meme.verify
+        end
+      end
+    end
+  end
+
+=== Stubs
+
+  def test_stale_eh
+    obj_under_test = Something.new
+
+    refute obj_under_test.stale?
+
+    Time.stub :now, Time.at(0) do   # stub goes away once the block is done
+      assert obj_under_test.stale?
+    end
+  end
+
+A note on stubbing: In order to stub a method, the method must
+actually exist prior to stubbing. Use a singleton method to create a
+new non-existing method:
+
+  def obj_under_test.fake_method
+    ...
+  end
+
+=== Customizable Test Runner Types:
+
+MiniTest::Unit.runner=(runner) provides an easy way of creating custom
+test runners for specialized needs. Justin Weiss provides the
+following real-world example to create an alternative to regular
+fixture loading:
+
+  class MiniTestWithHooks::Unit < MiniTest::Unit
+    def before_suites
+    end
+
+    def after_suites
+    end
+
+    def _run_suites(suites, type)
+      begin
+        before_suites
+        super(suites, type)
+      ensure
+        after_suites
+      end
+    end
+
+    def _run_suite(suite, type)
+      begin
+        suite.before_suite
+        super(suite, type)
+      ensure
+        suite.after_suite
+      end
+    end
+  end
+
+  module MiniTestWithTransactions
+    class Unit < MiniTestWithHooks::Unit
+      include TestSetupHelper
+
+      def before_suites
+        super
+        setup_nested_transactions
+        # load any data we want available for all tests
+      end
+
+      def after_suites
+        teardown_nested_transactions
+        super
+      end
+    end
+  end
+
+  MiniTest::Unit.runner = MiniTestWithTransactions::Unit.new
+
+== FAQ
+
+=== How to test SimpleDelegates?
+
+The following implementation and test:
+
+    class Worker < SimpleDelegator
+      def work
+      end
+    end
+
+    describe Worker do
+      before do
+        @worker = Worker.new(Object.new)
+      end
+
+      it "must respond to work" do
+        @worker.must_respond_to :work
+      end
+    end
+
+outputs a failure:
+
+      1) Failure:
+    Worker#test_0001_must respond to work [bug11.rb:16]:
+    Expected #<Object:0x007f9e7184f0a0> (Object) to respond to #work.
+
+Worker is a SimpleDelegate which in 1.9+ is a subclass of BasicObject.
+Expectations are put on Object (one level down) so the Worker
+(SimpleDelegate) hits `method_missing` and delegates down to the
+`Object.new` instance. That object doesn't respond to work so the test
+fails.
+
+You can bypass `SimpleDelegate#method_missing` by extending the worker
+with `MiniTest::Expectations`. You can either do that in your setup at
+the instance level, like:
+
+    before do
+      @worker = Worker.new(Object.new)
+      @worker.extend MiniTest::Expectations
+    end
+
+or you can extend the Worker class (within the test file!), like:
+
+    class Worker
+      include ::MiniTest::Expectations
+    end
+
+== Known Extensions:
+
+capybara_minitest_spec      :: Bridge between Capybara RSpec matchers and MiniTest::Spec expectations (e.g. page.must_have_content('Title')).
+minispec-metadata           :: Metadata for describe/it blocks
+                               (e.g. `it 'requires JS driver', js: true do`)
+minitest-ansi               :: Colorize minitest output with ANSI colors.
+minitest-around             :: Around block for minitest. An alternative to setup/teardown dance.
+minitest-capistrano         :: Assertions and expectations for testing Capistrano recipes
+minitest-capybara           :: Capybara matchers support for minitest unit and spec
+minitest-chef-handler       :: Run Minitest suites as Chef report handlers
+minitest-ci                 :: CI reporter plugin for MiniTest.
+minitest-colorize           :: Colorize MiniTest output and show failing tests instantly.
+minitest-context            :: Defines contexts for code reuse in MiniTest
+                               specs that share common expectations.
+minitest-debugger           :: Wraps assert so failed assertions drop into
+                               the ruby debugger.
+minitest-display            :: Patches MiniTest to allow for an easily configurable output.
+minitest-emoji              :: Print out emoji for your test passes, fails, and skips.
+minitest-english            :: Semantically symmetric aliases for assertions and expectations.
+minitest-excludes           :: Clean API for excluding certain tests you
+                               don't want to run under certain conditions.
+minitest-firemock           :: Makes your MiniTest mocks more resilient.
+minitest-great_expectations :: Generally useful additions to minitest's assertions and expectations
+minitest-growl              :: Test notifier for minitest via growl.
+minitest-implicit-subject   :: Implicit declaration of the test subject.
+minitest-instrument         :: Instrument ActiveSupport::Notifications when
+                               test method is executed
+minitest-instrument-db      :: Store information about speed of test
+                               execution provided by minitest-instrument in database
+minitest-libnotify          :: Test notifier for minitest via libnotify.
+minitest-macruby            :: Provides extensions to minitest for macruby UI testing.
+minitest-matchers           :: Adds support for RSpec-style matchers to minitest.
+minitest-metadata           :: Annotate tests with metadata (key-value).
+minitest-mongoid            :: Mongoid assertion matchers for MiniTest
+minitest-must_not           :: Provides must_not as an alias for wont in MiniTest
+minitest-nc                 :: Test notifier for minitest via Mountain Lion's Notification Center
+minitest-predicates         :: Adds support for .predicate? methods
+minitest-rails              :: MiniTest integration for Rails 3.x
+minitest-rails-capybara     :: Capybara integration for MiniTest::Rails
+minitest-reporters          :: Create customizable MiniTest output formats
+minitest-should_syntax      :: RSpec-style +x.should == y+ assertions for MiniTest
+minitest-shouldify          :: Adding all manner of shoulds to MiniTest (bad idea)
+minitest-spec-context       :: Provides rspec-ish context method to MiniTest::Spec
+minitest-spec-magic         :: Minitest::Spec extensions for Rails and beyond
+minitest-spec-rails         :: Drop in MiniTest::Spec superclass for ActiveSupport::TestCase.
+minitest-stub-const         :: Stub constants for the duration of a block
+minitest-tags               :: add tags for minitest
+minitest-wscolor            :: Yet another test colorizer.
+minitest_owrapper           :: Get tests results as a TestResult object.
+minitest_should             :: Shoulda style syntax for minitest test::unit.
+minitest_tu_shim            :: minitest_tu_shim bridges between test/unit and minitest.
+mongoid-minitest            :: MiniTest matchers for Mongoid.
+pry-rescue                  :: A pry plugin w/ minitest support. See pry-rescue/minitest.rb.
+
+== Unknown Extensions:
+
+Authors... Please send me a pull request with a description of your minitest extension.
+
+* assay-minitest
+* detroit-minitest
+* em-minitest-spec
+* flexmock-minitest
+* guard-minitest
+* guard-minitest-decisiv
+* minitest-activemodel
+* minitest-ar-assertions
+* minitest-capybara-unit
+* minitest-colorer
+* minitest-deluxe
+* minitest-extra-assertions
+* minitest-rails-shoulda
+* minitest-spec
+* minitest-spec-should
+* minitest-sugar
+* minitest_should
+* mongoid-minitest
+* spork-minitest
+
+== REQUIREMENTS:
+
+* Ruby 1.8, maybe even 1.6 or lower. No magic is involved.
+
+== INSTALL:
+
+  sudo gem install minitest
+
+On 1.9, you already have it. To get newer candy you can still install
+the gem, but you'll need to activate the gem explicitly to use it:
+
+  require 'rubygems'
+  gem 'minitest' # ensures you're using the gem, and not the built in MT
+  require 'minitest/autorun'
+
+  # ... usual testing stuffs ...
+
+DO NOTE: There is a serious problem with the way that ruby 1.9/2.0
+packages their own gems. They install a gem specification file, but
+don't install the gem contents in the gem path. This messes up
+Gem.find_files and many other things (gem which, gem contents, etc).
+
+Just install minitest as a gem for real and you'll be happier.
+
+== LICENSE:
+
+(The MIT License)
+
+Copyright (c) Ryan Davis, seattle.rb
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+'Software'), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/tool/lib/minitest/autorun.rb b/tool/lib/minitest/autorun.rb
new file mode 100644
index 0000000000..844096623c
--- /dev/null
+++ b/tool/lib/minitest/autorun.rb
@@ -0,0 +1,14 @@
+# encoding: utf-8
+# frozen_string_literal: true
+
+begin
+  require 'rubygems'
+  gem 'minitest'
+rescue Gem::LoadError
+  # do nothing
+end
+
+require 'minitest/unit'
+require 'minitest/mock'
+
+MiniTest::Unit.autorun
diff --git a/tool/lib/minitest/benchmark.rb b/tool/lib/minitest/benchmark.rb
new file mode 100644
index 0000000000..b3f2bc28b3
--- /dev/null
+++ b/tool/lib/minitest/benchmark.rb
@@ -0,0 +1,418 @@
+# encoding: utf-8
+# frozen_string_literal: true
+
+require 'minitest/unit'
+
+class MiniTest::Unit # :nodoc:
+  def run_benchmarks # :nodoc:
+    _run_anything :benchmark
+  end
+
+  def benchmark_suite_header suite # :nodoc:
+    "\n#{suite}\t#{suite.bench_range.join("\t")}"
+  end
+
+  class TestCase
+    ##
+    # Returns a set of ranges stepped exponentially from +min+ to
+    # +max+ by powers of +base+. Eg:
+    #
+    #   bench_exp(2, 16, 2) # => [2, 4, 8, 16]
+
+    def self.bench_exp min, max, base = 10
+      min = (Math.log10(min) / Math.log10(base)).to_i
+      max = (Math.log10(max) / Math.log10(base)).to_i
+
+      (min..max).map { |m| base ** m }.to_a
+    end
+
+    ##
+    # Returns a set of ranges stepped linearly from +min+ to +max+ by
+    # +step+. Eg:
+    #
+    #   bench_linear(20, 40, 10) # => [20, 30, 40]
+
+    def self.bench_linear min, max, step = 10
+      (min..max).step(step).to_a
+    rescue LocalJumpError # 1.8.6
+      r = []; (min..max).step(step) { |n| r << n }; r
+    end
+
+    ##
+    # Returns the benchmark methods (methods that start with bench_)
+    # for that class.
+
+    def self.benchmark_methods # :nodoc:
+      public_instance_methods(true).grep(/^bench_/).map { |m| m.to_s }.sort
+    end
+
+    ##
+    # Returns all test suites that have benchmark methods.
+
+    def self.benchmark_suites
+      TestCase.test_suites.reject { |s| s.benchmark_methods.empty? }
+    end
+
+    ##
+    # Specifies the ranges used for benchmarking for that class.
+    # Defaults to exponential growth from 1 to 10k by powers of 10.
+    # Override if you need different ranges for your benchmarks.
+    #
+    # See also: ::bench_exp and ::bench_linear.
+
+    def self.bench_range
+      bench_exp 1, 10_000
+    end
+
+    ##
+    # Runs the given +work+, gathering the times of each run. Range
+    # and times are then passed to a given +validation+ proc. Outputs
+    # the benchmark name and times in tab-separated format, making it
+    # easy to paste into a spreadsheet for graphing or further
+    # analysis.
+    #
+    # Ranges are specified by ::bench_range.
+    #
+    # Eg:
+    #
+    #   def bench_algorithm
+    #     validation = proc { |x, y| ... }
+    #     assert_performance validation do |n|
+    #       @obj.algorithm(n)
+    #     end
+    #   end
+
+    def assert_performance validation, &work
+      range = self.class.bench_range
+
+      io.print "#{__name__}"
+
+      times = []
+
+      range.each do |x|
+        GC.start
+        t0 = Time.now
+        instance_exec(x, &work)
+        t = Time.now - t0
+
+        io.print "\t%9.6f" % t
+        times << t
+      end
+      io.puts
+
+      validation[range, times]
+    end
+
+    ##
+    # Runs the given +work+ and asserts that the times gathered fit to
+    # match a constant rate (eg, linear slope == 0) within a given
+    # +threshold+. Note: because we're testing for a slope of 0, R^2
+    # is not a good determining factor for the fit, so the threshold
+    # is applied against the slope itself. As such, you probably want
+    # to tighten it from the default.
+    #
+    # See http://www.graphpad.com/curvefit/goodness_of_fit.htm for
+    # more details.
+    #
+    # Fit is calculated by #fit_linear.
+    #
+    # Ranges are specified by ::bench_range.
+    #
+    # Eg:
+    #
+    #   def bench_algorithm
+    #     assert_performance_constant 0.9999 do |n|
+    #       @obj.algorithm(n)
+    #     end
+    #   end
+
+    def assert_performance_constant threshold = 0.99, &work
+      validation = proc do |range, times|
+        a, b, rr = fit_linear range, times
+        assert_in_delta 0, b, 1 - threshold
+        [a, b, rr]
+      end
+
+      assert_performance validation, &work
+    end
+
+    ##
+    # Runs the given +work+ and asserts that the times gathered fit to
+    # match a exponential curve within a given error +threshold+.
+    #
+    # Fit is calculated by #fit_exponential.
+    #
+    # Ranges are specified by ::bench_range.
+    #
+    # Eg:
+    #
+    #   def bench_algorithm
+    #     assert_performance_exponential 0.9999 do |n|
+    #       @obj.algorithm(n)
+    #     end
+    #   end
+
+    def assert_performance_exponential threshold = 0.99, &work
+      assert_performance validation_for_fit(:exponential, threshold), &work
+    end
+
+    ##
+    # Runs the given +work+ and asserts that the times gathered fit to
+    # match a logarithmic curve within a given error +threshold+.
+    #
+    # Fit is calculated by #fit_logarithmic.
+    #
+    # Ranges are specified by ::bench_range.
+    #
+    # Eg:
+    #
+    #   def bench_algorithm
+    #     assert_performance_logarithmic 0.9999 do |n|
+    #       @obj.algorithm(n)
+    #     end
+    #   end
+
+    def assert_performance_logarithmic threshold = 0.99, &work
+      assert_performance validation_for_fit(:logarithmic, threshold), &work
+    end
+
+    ##
+    # Runs the given +work+ and asserts that the times gathered fit to
+    # match a straight line within a given error +threshold+.
+    #
+    # Fit is calculated by #fit_linear.
+    #
+    # Ranges are specified by ::bench_range.
+    #
+    # Eg:
+    #
+    #   def bench_algorithm
+    #     assert_performance_linear 0.9999 do |n|
+    #       @obj.algorithm(n)
+    #     end
+    #   end
+
+    def assert_performance_linear threshold = 0.99, &work
+      assert_performance validation_for_fit(:linear, threshold), &work
+    end
+
+    ##
+    # Runs the given +work+ and asserts that the times gathered curve
+    # fit to match a power curve within a given error +threshold+.
+    #
+    # Fit is calculated by #fit_power.
+    #
+    # Ranges are specified by ::bench_range.
+    #
+    # Eg:
+    #
+    #   def bench_algorithm
+    #     assert_performance_power 0.9999 do |x|
+    #       @obj.algorithm
+    #     end
+    #   end
+
+    def assert_performance_power threshold = 0.99, &work
+      assert_performance validation_for_fit(:power, threshold), &work
+    end
+
+    ##
+    # Takes an array of x/y pairs and calculates the general R^2 value.
+    #
+    # See: http://en.wikipedia.org/wiki/Coefficient_of_determination
+
+    def fit_error xys
+      y_bar  = sigma(xys) { |x, y| y } / xys.size.to_f
+      ss_tot = sigma(xys) { |x, y| (y    - y_bar) ** 2 }
+      ss_err = sigma(xys) { |x, y| (yield(x) - y) ** 2 }
+
+      1 - (ss_err / ss_tot)
+    end
+
+    ##
+    # To fit a functional form: y = ae^(bx).
+    #
+    # Takes x and y values and returns [a, b, r^2].
+    #
+    # See: http://mathworld.wolfram.com/LeastSquaresFittingExponential.html
+
+    def fit_exponential xs, ys
+      n     = xs.size
+      xys   = xs.zip(ys)
+      sxlny = sigma(xys) { |x,y| x * Math.log(y) }
+      slny  = sigma(xys) { |x,y| Math.log(y)     }
+      sx2   = sigma(xys) { |x,y| x * x           }
+      sx    = sigma xs
+
+      c = n * sx2 - sx ** 2
+      a = (slny * sx2 - sx * sxlny) / c
+      b = ( n * sxlny - sx * slny ) / c
+
+      return Math.exp(a), b, fit_error(xys) { |x| Math.exp(a + b * x) }
+    end
+
+    ##
+    # To fit a functional form: y = a + b*ln(x).
+    #
+    # Takes x and y values and returns [a, b, r^2].
+    #
+    # See: http://mathworld.wolfram.com/LeastSquaresFittingLogarithmic.html
+
+    def fit_logarithmic xs, ys
+      n     = xs.size
+      xys   = xs.zip(ys)
+      slnx2 = sigma(xys) { |x,y| Math.log(x) ** 2 }
+      slnx  = sigma(xys) { |x,y| Math.log(x)      }
+      sylnx = sigma(xys) { |x,y| y * Math.log(x)  }
+      sy    = sigma(xys) { |x,y| y                }
+
+      c = n * slnx2 - slnx ** 2
+      b = ( n * sylnx - sy * slnx ) / c
+      a = (sy - b * slnx) / n
+
+      return a, b, fit_error(xys) { |x| a + b * Math.log(x) }
+    end
+
+
+    ##
+    # Fits the functional form: a + bx.
+    #
+    # Takes x and y values and returns [a, b, r^2].
+    #
+    # See: http://mathworld.wolfram.com/LeastSquaresFitting.html
+
+    def fit_linear xs, ys
+      n   = xs.size
+      xys = xs.zip(ys)
+      sx  = sigma xs
+      sy  = sigma ys
+      sx2 = sigma(xs)  { |x|   x ** 2 }
+      sxy = sigma(xys) { |x,y| x * y  }
+
+      c = n * sx2 - sx**2
+      a = (sy * sx2 - sx * sxy) / c
+      b = ( n * sxy - sx * sy ) / c
+
+      return a, b, fit_error(xys) { |x| a + b * x }
+    end
+
+    ##
+    # To fit a functional form: y = ax^b.
+    #
+    # Takes x and y values and returns [a, b, r^2].
+    #
+    # See: http://mathworld.wolfram.com/LeastSquaresFittingPowerLaw.html
+
+    def fit_power xs, ys
+      n       = xs.size
+      xys     = xs.zip(ys)
+      slnxlny = sigma(xys) { |x, y| Math.log(x) * Math.log(y) }
+      slnx    = sigma(xs)  { |x   | Math.log(x)               }
+      slny    = sigma(ys)  { |   y| Math.log(y)               }
+      slnx2   = sigma(xs)  { |x   | Math.log(x) ** 2          }
+
+      b = (n * slnxlny - slnx * slny) / (n * slnx2 - slnx ** 2);
+      a = (slny - b * slnx) / n
+
+      return Math.exp(a), b, fit_error(xys) { |x| (Math.exp(a) * (x ** b)) }
+    end
+
+    ##
+    # Enumerates over +enum+ mapping +block+ if given, returning the
+    # sum of the result. Eg:
+    #
+    #   sigma([1, 2, 3])                # => 1 + 2 + 3 => 7
+    #   sigma([1, 2, 3]) { |n| n ** 2 } # => 1 + 4 + 9 => 14
+
+    def sigma enum, &block
+      enum = enum.map(&block) if block
+      enum.inject { |sum, n| sum + n }
+    end
+
+    ##
+    # Returns a proc that calls the specified fit method and asserts
+    # that the error is within a tolerable threshold.
+
+    def validation_for_fit msg, threshold
+      proc do |range, times|
+        a, b, rr = send "fit_#{msg}", range, times
+        assert_operator rr, :>=, threshold
+        [a, b, rr]
+      end
+    end
+  end
+end
+
+class MiniTest::Spec
+  ##
+  # This is used to define a new benchmark method. You usually don't
+  # use this directly and is intended for those needing to write new
+  # performance curve fits (eg: you need a specific polynomial fit).
+  #
+  # See ::bench_performance_linear for an example of how to use this.
+
+  def self.bench name, &block
+    define_method "bench_#{name.gsub(/\W+/, '_')}", &block
+  end
+
+  ##
+  # Specifies the ranges used for benchmarking for that class.
+  #
+  #   bench_range do
+  #     bench_exp(2, 16, 2)
+  #   end
+  #
+  # See Unit::TestCase.bench_range for more details.
+
+  def self.bench_range &block
+    return super unless block
+
+    meta = (class << self; self; end)
+    meta.send :define_method, "bench_range", &block
+  end
+
+  ##
+  # Create a benchmark that verifies that the performance is linear.
+  #
+  #   describe "my class" do
+  #     bench_performance_linear "fast_algorithm", 0.9999 do |n|
+  #       @obj.fast_algorithm(n)
+  #     end
+  #   end
+
+  def self.bench_performance_linear name, threshold = 0.99, &work
+    bench name do
+      assert_performance_linear threshold, &work
+    end
+  end
+
+  ##
+  # Create a benchmark that verifies that the performance is constant.
+  #
+  #   describe "my class" do
+  #     bench_performance_constant "zoom_algorithm!" do |n|
+  #       @obj.zoom_algorithm!(n)
+  #     end
+  #   end
+
+  def self.bench_performance_constant name, threshold = 0.99, &work
+    bench name do
+      assert_performance_constant threshold, &work
+    end
+  end
+
+  ##
+  # Create a benchmark that verifies that the performance is exponential.
+  #
+  #   describe "my class" do
+  #     bench_performance_exponential "algorithm" do |n|
+  #       @obj.algorithm(n)
+  #     end
+  #   end
+
+  def self.bench_performance_exponential name, threshold = 0.99, &work
+    bench name do
+      assert_performance_exponential threshold, &work
+    end
+  end
+end
diff --git a/tool/lib/minitest/mock.rb b/tool/lib/minitest/mock.rb
new file mode 100644
index 0000000000..224b06cb89
--- /dev/null
+++ b/tool/lib/minitest/mock.rb
@@ -0,0 +1,196 @@
+# encoding: utf-8
+# frozen_string_literal: true
+
+class MockExpectationError < StandardError; end # :nodoc:
+
+##
+# A simple and clean mock object framework.
+
+module MiniTest # :nodoc:
+
+  ##
+  # All mock objects are an instance of Mock
+
+  class Mock
+    alias :__respond_to? :respond_to?
+
+    skip_methods = %w(object_id respond_to_missing? inspect === to_s)
+
+    instance_methods.each do |m|
+      undef_method m unless skip_methods.include?(m.to_s) || m =~ /^__/
+    end
+
+    def initialize # :nodoc:
+      @expected_calls = Hash.new { |calls, name| calls[name] = [] }
+      @actual_calls   = Hash.new { |calls, name| calls[name] = [] }
+    end
+
+    ##
+    # Expect that method +name+ is called, optionally with +args+ or a
+    # +blk+, and returns +retval+.
+    #
+    #   @mock.expect(:meaning_of_life, 42)
+    #   @mock.meaning_of_life # => 42
+    #
+    #   @mock.expect(:do_something_with, true, [some_obj, true])
+    #   @mock.do_something_with(some_obj, true) # => true
+    #
+    #   @mock.expect(:do_something_else, true) do |a1, a2|
+    #     a1 == "buggs" && a2 == :bunny
+    #   end
+    #
+    # +args+ is compared to the expected args using case equality (ie, the
+    # '===' operator), allowing for less specific expectations.
+    #
+    #   @mock.expect(:uses_any_string, true, [String])
+    #   @mock.uses_any_string("foo") # => true
+    #   @mock.verify  # => true
+    #
+    #   @mock.expect(:uses_one_string, true, ["foo"]
+    #   @mock.uses_one_string("bar") # => true
+    #   @mock.verify  # => raises MockExpectationError
+
+    def expect(name, retval, args=[], &blk)
+      if block_given?
+        raise ArgumentError, "args ignored when block given" unless args.empty?
+        @expected_calls[name] << { :retval => retval, :block => blk }
+      else
+        raise ArgumentError, "args must be an array" unless Array === args
+        @expected_calls[name] << { :retval => retval, :args => args }
+      end
+      self
+    end
+
+    def __call name, data # :nodoc:
+      case data
+      when Hash then
+        "#{name}(#{data[:args].inspect[1..-2]}) => #{data[:retval].inspect}"
+      else
+        data.map { |d| __call name, d }.join ", "
+      end
+    end
+
+    ##
+    # Verify that all methods were called as expected. Raises
+    # +MockExpectationError+ if the mock object was not called as
+    # expected.
+
+    def verify
+      @expected_calls.each do |name, calls|
+        calls.each do |expected|
+          msg1 = "expected #{__call name, expected}"
+          msg2 = "#{msg1}, got [#{__call name, @actual_calls[name]}]"
+
+          raise MockExpectationError, msg2 if
+            @actual_calls.has_key?(name) and
+            not @actual_calls[name].include?(expected)
+
+          raise MockExpectationError, msg1 unless
+            @actual_calls.has_key?(name) and
+            @actual_calls[name].include?(expected)
+        end
+      end
+      true
+    end
+
+    def method_missing(sym, *args) # :nodoc:
+      unless @expected_calls.has_key?(sym) then
+        raise NoMethodError, "unmocked method %p, expected one of %p" %
+          [sym, @expected_calls.keys.sort_by(&:to_s)]
+      end
+
+      index = @actual_calls[sym].length
+      expected_call = @expected_calls[sym][index]
+
+      unless expected_call then
+        raise MockExpectationError, "No more expects available for %p: %p" %
+          [sym, args]
+      end
+
+      expected_args, retval, val_block =
+        expected_call.values_at(:args, :retval, :block)
+
+      if val_block then
+        raise MockExpectationError, "mocked method %p failed block w/ %p" %
+          [sym, args] unless val_block.call(args)
+
+        # keep "verify" happy
+        @actual_calls[sym] << expected_call
+        return retval
+      end
+
+      if expected_args.size != args.size then
+        raise ArgumentError, "mocked method %p expects %d arguments, got %d" %
+          [sym, expected_args.size, args.size]
+      end
+
+      fully_matched = expected_args.zip(args).all? { |mod, a|
+        mod === a or mod == a
+      }
+
+      unless fully_matched then
+        raise MockExpectationError, "mocked method %p called with unexpected arguments %p" %
+          [sym, args]
+      end
+
+      @actual_calls[sym] << {
+        :retval => retval,
+        :args => expected_args.zip(args).map { |mod, a| mod === a ? mod : a }
+      }
+
+      retval
+    end
+
+    def respond_to?(sym, include_private = false) # :nodoc:
+      return true if @expected_calls.has_key?(sym.to_sym)
+      return __respond_to?(sym, include_private)
+    end
+  end
+end
+
+class Object # :nodoc:
+
+  ##
+  # Add a temporary stubbed method replacing +name+ for the duration
+  # of the +block+. If +val_or_callable+ responds to #call, then it
+  # returns the result of calling it, otherwise returns the value
+  # as-is. Cleans up the stub at the end of the +block+. The method
+  # +name+ must exist before stubbing.
+  #
+  #     def test_stale_eh
+  #       obj_under_test = Something.new
+  #       refute obj_under_test.stale?
+  #
+  #       Time.stub :now, Time.at(0) do
+  #         assert obj_under_test.stale?
+  #       end
+  #     end
+
+  def stub name, val_or_callable, &block
+    new_name = "__minitest_stub__#{name}"
+
+    metaclass = class << self; self; end
+
+    if respond_to? name and not methods.map(&:to_s).include? name.to_s then
+      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|
+      if val_or_callable.respond_to? :call then
+        val_or_callable.call(*args)
+      else
+        val_or_callable
+      end
+    end
+
+    yield self
+  ensure
+    metaclass.send :undef_method, name
+    metaclass.send :alias_method, name, new_name
+    metaclass.send :undef_method, new_name
+  end
+end
diff --git a/tool/lib/minitest/unit.rb b/tool/lib/minitest/unit.rb
new file mode 100644
index 0000000000..d922a5fc41
--- /dev/null
+++ b/tool/lib/minitest/unit.rb
@@ -0,0 +1,1420 @@
+# encoding: utf-8
+# frozen_string_literal: true
+
+require "optparse"
+require "rbconfig"
+require "leakchecker"
+
+##
+# Minimal (mostly drop-in) replacement for test-unit.
+#
+# :include: README.txt
+
+module MiniTest
+
+  def self.const_missing name # :nodoc:
+    case name
+    when :MINI_DIR then
+      msg = "MiniTest::MINI_DIR was removed. Don't violate other's internals."
+      warn "WAR\NING: #{msg}"
+      warn "WAR\NING: Used by #{caller.first}."
+      const_set :MINI_DIR, "bad value"
+    else
+      super
+    end
+  end
+
+  ##
+  # Assertion base class
+
+  class Assertion < Exception; end
+
+  ##
+  # Assertion raised when skipping a test
+
+  class Skip < Assertion; end
+
+  class << self
+    ##
+    # Filter object for backtraces.
+
+    attr_accessor :backtrace_filter
+  end
+
+  class BacktraceFilter # :nodoc:
+    def filter bt
+      return ["No backtrace"] unless bt
+
+      new_bt = []
+
+      unless $DEBUG then
+        bt.each do |line|
+          break if line =~ /lib\/minitest/
+          new_bt << line
+        end
+
+        new_bt = bt.reject { |line| line =~ /lib\/minitest/ } if new_bt.empty?
+        new_bt = bt.dup if new_bt.empty?
+      else
+        new_bt = bt.dup
+      end
+
+      new_bt
+    end
+  end
+
+  self.backtrace_filter = BacktraceFilter.new
+
+  def self.filter_backtrace bt # :nodoc:
+    backtrace_filter.filter bt
+  end
+
+  ##
+  # MiniTest Assertions.  All assertion methods accept a +msg+ which is
+  # printed if the assertion fails.
+
+  module Assertions
+    ##
+    # Returns the diff command to use in #diff. Tries to intelligently
+    # figure out what diff to use.
+
+    def self.diff
+      unless defined? @diff
+        exe = RbConfig::CONFIG['EXEEXT']
+        @diff = %W"gdiff#{exe} diff#{exe}".find do |diff|
+          if system(diff, "-u", __FILE__, __FILE__)
+            break "#{diff} -u"
+          end
+        end
+      end
+
+      @diff
+    end
+
+    ##
+    # Set the diff command to use in #diff.
+
+    def self.diff= o
+      @diff = o
+    end
+
+    ##
+    # Returns a diff between +exp+ and +act+. If there is no known
+    # diff command or if it doesn't make sense to diff the output
+    # (single line, short output), then it simply returns a basic
+    # comparison between the two.
+
+    def diff exp, act
+      require "tempfile"
+
+      expect = mu_pp_for_diff exp
+      butwas = mu_pp_for_diff act
+      result = nil
+
+      need_to_diff =
+        MiniTest::Assertions.diff &&
+        (expect.include?("\n")    ||
+         butwas.include?("\n")    ||
+         expect.size > 30         ||
+         butwas.size > 30         ||
+         expect == butwas)
+
+      return "Expected: #{mu_pp exp}\n  Actual: #{mu_pp act}" unless
+        need_to_diff
+
+      tempfile_a = nil
+      tempfile_b = nil
+
+      Tempfile.open("expect") do |a|
+        tempfile_a = a
+        a.puts expect
+        a.flush
+
+        Tempfile.open("butwas") do |b|
+          tempfile_b = b
+          b.puts butwas
+          b.flush
+
+          result = `#{MiniTest::Assertions.diff} #{a.path} #{b.path}`
+          result.sub!(/^\-\-\- .+/, "--- expected")
+          result.sub!(/^\+\+\+ .+/, "+++ actual")
+
+          if result.empty? then
+            klass = exp.class
+            result = [
+                      "No visible difference in the #{klass}#inspect output.\n",
+                      "You should look at the implementation of #== on ",
+                      "#{klass} or its members.\n",
+                      expect,
+                     ].join
+          end
+        end
+      end
+
+      result
+    ensure
+      tempfile_a.close! if tempfile_a
+      tempfile_b.close! if tempfile_b
+    end
+
+    ##
+    # This returns a human-readable version of +obj+. By default
+    # #inspect is called. You can override this to use #pretty_print
+    # if you want.
+
+    def mu_pp obj
+      s = obj.inspect
+      s = s.encode Encoding.default_external if defined? Encoding
+      s
+    end
+
+    ##
+    # This returns a diff-able human-readable version of +obj+. This
+    # differs from the regular mu_pp because it expands escaped
+    # newlines and makes hex-values generic (like object_ids). This
+    # uses mu_pp to do the first pass and then cleans it up.
+
+    def mu_pp_for_diff obj
+      mu_pp(obj).gsub(/(?<!\\)(?:\\\\)*\K\\n/, "\n").gsub(/:0x[a-fA-F0-9]{4,}/m, ':0xXXXXXX')
+    end
+
+    def _assertions= n # :nodoc:
+      @_assertions = n
+    end
+
+    def _assertions # :nodoc:
+      @_assertions ||= 0
+    end
+
+    ##
+    # Fails unless +test+ is a true value.
+
+    def assert test, msg = nil
+      msg ||= "Failed assertion, no message given."
+      self._assertions += 1
+      unless test then
+        msg = msg.call if Proc === msg
+        raise MiniTest::Assertion, msg
+      end
+      true
+    end
+
+    ##
+    # Fails unless +obj+ is empty.
+
+    def assert_empty obj, msg = nil
+      msg = message(msg) { "Expected #{mu_pp(obj)} to be empty" }
+      assert_respond_to obj, :empty?
+      assert obj.empty?, msg
+    end
+
+    ##
+    # Fails unless <tt>exp == act</tt> printing the difference between
+    # the two, if possible.
+    #
+    # If there is no visible difference but the assertion fails, you
+    # should suspect that your #== is buggy, or your inspect output is
+    # missing crucial details.
+    #
+    # For floats use assert_in_delta.
+    #
+    # See also: MiniTest::Assertions.diff
+
+    def assert_equal exp, act, msg = nil
+      msg = message(msg, "") { diff exp, act }
+      assert exp == act, msg
+    end
+
+    ##
+    # For comparing Floats.  Fails unless +exp+ and +act+ are within +delta+
+    # of each other.
+    #
+    #   assert_in_delta Math::PI, (22.0 / 7.0), 0.01
+
+    def assert_in_delta exp, act, delta = 0.001, msg = nil
+      n = (exp - act).abs
+      msg = message(msg) {
+        "Expected |#{exp} - #{act}| (#{n}) to be <= #{delta}"
+      }
+      assert delta >= n, msg
+    end
+
+    ##
+    # For comparing Floats.  Fails unless +exp+ and +act+ have a relative
+    # error less than +epsilon+.
+
+    def assert_in_epsilon a, b, epsilon = 0.001, msg = nil
+      assert_in_delta a, b, [a.abs, b.abs].min * epsilon, msg
+    end
+
+    ##
+    # Fails unless +collection+ includes +obj+.
+
+    def assert_includes collection, obj, msg = nil
+      msg = message(msg) {
+        "Expected #{mu_pp(collection)} to include #{mu_pp(obj)}"
+      }
+      assert_respond_to collection, :include?
+      assert collection.include?(obj), msg
+    end
+
+    ##
+    # Fails unless +obj+ is an instance of +cls+.
+
+    def assert_instance_of cls, obj, msg = nil
+      msg = message(msg) {
+        "Expected #{mu_pp(obj)} to be an instance of #{cls}, not #{obj.class}"
+      }
+
+      assert obj.instance_of?(cls), msg
+    end
+
+    ##
+    # Fails unless +obj+ is a kind of +cls+.
+
+    def assert_kind_of cls, obj, msg = nil # TODO: merge with instance_of
+      msg = message(msg) {
+        "Expected #{mu_pp(obj)} to be a kind of #{cls}, not #{obj.class}" }
+
+      assert obj.kind_of?(cls), msg
+    end
+
+    ##
+    # Fails unless +matcher+ <tt>=~</tt> +obj+.
+
+    def assert_match matcher, obj, msg = nil
+      msg = message(msg) { "Expected #{mu_pp matcher} to match #{mu_pp obj}" }
+      assert_respond_to matcher, :"=~"
+      matcher = Regexp.new Regexp.escape matcher if String === matcher
+      assert matcher =~ obj, msg
+    end
+
+    ##
+    # Fails unless +obj+ is nil
+
+    def assert_nil obj, msg = nil
+      msg = message(msg) { "Expected #{mu_pp(obj)} to be nil" }
+      assert obj.nil?, msg
+    end
+
+    ##
+    # For testing with binary operators.
+    #
+    #   assert_operator 5, :<=, 4
+
+    def assert_operator o1, op, o2 = (predicate = true; nil), msg = nil
+      return assert_predicate o1, op, msg if predicate
+      msg = message(msg) { "Expected #{mu_pp(o1)} to be #{op} #{mu_pp(o2)}" }
+      assert o1.__send__(op, o2), msg
+    end
+
+    ##
+    # Fails if stdout or stderr do not output the expected results.
+    # Pass in nil if you don't care about that streams output. Pass in
+    # "" if you require it to be silent. Pass in a regexp if you want
+    # to pattern match.
+    #
+    # NOTE: this uses #capture_io, not #capture_subprocess_io.
+    #
+    # See also: #assert_silent
+
+    def assert_output stdout = nil, stderr = nil
+      out, err = capture_io do
+        yield
+      end
+
+      err_msg = Regexp === stderr ? :assert_match : :assert_equal if stderr
+      out_msg = Regexp === stdout ? :assert_match : :assert_equal if stdout
+
+      y = send err_msg, stderr, err, "In stderr" if err_msg
+      x = send out_msg, stdout, out, "In stdout" if out_msg
+
+      (!stdout || x) && (!stderr || y)
+    end
+
+    ##
+    # For testing with predicates.
+    #
+    #   assert_predicate str, :empty?
+    #
+    # This is really meant for specs and is front-ended by assert_operator:
+    #
+    #   str.must_be :empty?
+
+    def assert_predicate o1, op, msg = nil
+      msg = message(msg) { "Expected #{mu_pp(o1)} to be #{op}" }
+      assert o1.__send__(op), msg
+    end
+
+    ##
+    # Fails unless the block raises one of +exp+. Returns the
+    # exception matched so you can check the message, attributes, etc.
+
+    def assert_raises *exp
+      msg = "#{exp.pop}.\n" if String === exp.last
+
+      begin
+        yield
+      rescue MiniTest::Skip => e
+        return e if exp.include? MiniTest::Skip
+        raise e
+      rescue Exception => e
+        expected = exp.any? { |ex|
+          if ex.instance_of? Module then
+            e.kind_of? ex
+          else
+            e.instance_of? ex
+          end
+        }
+
+        assert expected, proc {
+          exception_details(e, "#{msg}#{mu_pp(exp)} exception expected, not")
+        }
+
+        return e
+      end
+
+      exp = exp.first if exp.size == 1
+
+      flunk "#{msg}#{mu_pp(exp)} expected but nothing was raised."
+    end
+
+    ##
+    # Fails unless +obj+ responds to +meth+.
+
+    def assert_respond_to obj, meth, msg = nil
+      msg = message(msg) {
+        "Expected #{mu_pp(obj)} (#{obj.class}) to respond to ##{meth}"
+      }
+      assert obj.respond_to?(meth), msg
+    end
+
+    ##
+    # Fails unless +exp+ and +act+ are #equal?
+
+    def assert_same exp, act, msg = nil
+      msg = message(msg) {
+        data = [mu_pp(act), act.object_id, mu_pp(exp), exp.object_id]
+        "Expected %s (oid=%d) to be the same as %s (oid=%d)" % data
+      }
+      assert exp.equal?(act), msg
+    end
+
+    ##
+    # +send_ary+ is a receiver, message and arguments.
+    #
+    # Fails unless the call returns a true value
+    # TODO: I should prolly remove this from specs
+
+    def assert_send send_ary, m = nil
+      recv, msg, *args = send_ary
+      m = message(m) {
+        "Expected #{mu_pp(recv)}.#{msg}(*#{mu_pp(args)}) to return true" }
+      assert recv.__send__(msg, *args), m
+    end
+
+    ##
+    # Fails if the block outputs anything to stderr or stdout.
+    #
+    # See also: #assert_output
+
+    def assert_silent
+      assert_output "", "" do
+        yield
+      end
+    end
+
+    ##
+    # Fails unless the block throws +sym+
+
+    def assert_throws sym, msg = nil
+      default = "Expected #{mu_pp(sym)} to have been thrown"
+      caught = true
+      catch(sym) do
+        begin
+          yield
+        rescue ThreadError => e       # wtf?!? 1.8 + threads == suck
+          default += ", not \:#{e.message[/uncaught throw \`(\w+?)\'/, 1]}"
+        rescue ArgumentError => e     # 1.9 exception
+          default += ", not #{e.message.split(/ /).last}"
+        rescue NameError => e         # 1.8 exception
+          default += ", not #{e.name.inspect}"
+        end
+        caught = false
+      end
+
+      assert caught, message(msg) { default }
+    end
+
+    ##
+    # Captures $stdout and $stderr into strings:
+    #
+    #   out, err = capture_io do
+    #     puts "Some info"
+    #     warn "You did a bad thing"
+    #   end
+    #
+    #   assert_match %r%info%, out
+    #   assert_match %r%bad%, err
+    #
+    # NOTE: For efficiency, this method uses StringIO and does not
+    # capture IO for subprocesses. Use #capture_subprocess_io for
+    # that.
+
+    def capture_io
+      require 'stringio'
+
+      captured_stdout, captured_stderr = StringIO.new, StringIO.new
+
+      synchronize do
+        orig_stdout, orig_stderr = $stdout, $stderr
+        $stdout, $stderr         = captured_stdout, captured_stderr
+
+        begin
+          yield
+        ensure
+          $stdout = orig_stdout
+          $stderr = orig_stderr
+        end
+      end
+
+      return captured_stdout.string, captured_stderr.string
+    end
+
+    ##
+    # Captures $stdout and $stderr into strings, using Tempfile to
+    # ensure that subprocess IO is captured as well.
+    #
+    #   out, err = capture_subprocess_io do
+    #     system "echo Some info"
+    #     system "echo You did a bad thing 1>&2"
+    #   end
+    #
+    #   assert_match %r%info%, out
+    #   assert_match %r%bad%, err
+    #
+    # NOTE: This method is approximately 10x slower than #capture_io so
+    # only use it when you need to test the output of a subprocess.
+
+    def capture_subprocess_io
+      require 'tempfile'
+
+      captured_stdout, captured_stderr = Tempfile.new("out"), Tempfile.new("err")
+
+      synchronize do
+        orig_stdout, orig_stderr = $stdout.dup, $stderr.dup
+        $stdout.reopen captured_stdout
+        $stderr.reopen captured_stderr
+
+        begin
+          yield
+
+          $stdout.rewind
+          $stderr.rewind
+
+          [captured_stdout.read, captured_stderr.read]
+        ensure
+          $stdout.reopen orig_stdout
+          $stderr.reopen orig_stderr
+          orig_stdout.close
+          orig_stderr.close
+          captured_stdout.close!
+          captured_stderr.close!
+        end
+      end
+    end
+
+    ##
+    # Returns details for exception +e+
+
+    def exception_details e, msg
+      [
+       "#{msg}",
+       "Class: <#{e.class}>",
+       "Message: <#{e.message.inspect}>",
+       "---Backtrace---",
+       "#{MiniTest::filter_backtrace(e.backtrace).join("\n")}",
+       "---------------",
+      ].join "\n"
+    end
+
+    ##
+    # Fails with +msg+
+
+    def flunk msg = nil
+      msg ||= "Epic Fail!"
+      assert false, msg
+    end
+
+    ##
+    # Returns a proc that will output +msg+ along with the default message.
+
+    def message msg = nil, ending = ".", &default
+      proc {
+        msg = msg.call.chomp(".") if Proc === msg
+        custom_message = "#{msg}.\n" unless msg.nil? or msg.to_s.empty?
+        "#{custom_message}#{default.call}#{ending}"
+      }
+    end
+
+    ##
+    # used for counting assertions
+
+    def pass msg = nil
+      assert true
+    end
+
+    ##
+    # Fails if +test+ is a true value
+
+    def refute test, msg = nil
+      msg ||= "Failed refutation, no message given"
+      not assert(! test, msg)
+    end
+
+    ##
+    # Fails if +obj+ is empty.
+
+    def refute_empty obj, msg = nil
+      msg = message(msg) { "Expected #{mu_pp(obj)} to not be empty" }
+      assert_respond_to obj, :empty?
+      refute obj.empty?, msg
+    end
+
+    ##
+    # Fails if <tt>exp == act</tt>.
+    #
+    # For floats use refute_in_delta.
+
+    def refute_equal exp, act, msg = nil
+      msg = message(msg) {
+        "Expected #{mu_pp(act)} to not be equal to #{mu_pp(exp)}"
+      }
+      refute exp == act, msg
+    end
+
+    ##
+    # For comparing Floats.  Fails if +exp+ is within +delta+ of +act+.
+    #
+    #   refute_in_delta Math::PI, (22.0 / 7.0)
+
+    def refute_in_delta exp, act, delta = 0.001, msg = nil
+      n = (exp - act).abs
+      msg = message(msg) {
+        "Expected |#{exp} - #{act}| (#{n}) to not be <= #{delta}"
+      }
+      refute delta >= n, msg
+    end
+
+    ##
+    # For comparing Floats.  Fails if +exp+ and +act+ have a relative error
+    # less than +epsilon+.
+
+    def refute_in_epsilon a, b, epsilon = 0.001, msg = nil
+      refute_in_delta a, b, a * epsilon, msg
+    end
+
+    ##
+    # Fails if +collection+ includes +obj+.
+
+    def refute_includes collection, obj, msg = nil
+      msg = message(msg) {
+        "Expected #{mu_pp(collection)} to not include #{mu_pp(obj)}"
+      }
+      assert_respond_to collection, :include?
+      refute collection.include?(obj), msg
+    end
+
+    ##
+    # Fails if +obj+ is an instance of +cls+.
+
+    def refute_instance_of cls, obj, msg = nil
+      msg = message(msg) {
+        "Expected #{mu_pp(obj)} to not be an instance of #{cls}"
+      }
+      refute obj.instance_of?(cls), msg
+    end
+
+    ##
+    # Fails if +obj+ is a kind of +cls+.
+
+    def refute_kind_of cls, obj, msg = nil # TODO: merge with instance_of
+      msg = message(msg) { "Expected #{mu_pp(obj)} to not be a kind of #{cls}" }
+      refute obj.kind_of?(cls), msg
+    end
+
+    ##
+    # Fails if +matcher+ <tt>=~</tt> +obj+.
+
+    def refute_match matcher, obj, msg = nil
+      msg = message(msg) {"Expected #{mu_pp matcher} to not match #{mu_pp obj}"}
+      assert_respond_to matcher, :"=~"
+      matcher = Regexp.new Regexp.escape matcher if String === matcher
+      refute matcher =~ obj, msg
+    end
+
+    ##
+    # Fails if +obj+ is nil.
+
+    def refute_nil obj, msg = nil
+      msg = message(msg) { "Expected #{mu_pp(obj)} to not be nil" }
+      refute obj.nil?, msg
+    end
+
+    ##
+    # Fails if +o1+ is not +op+ +o2+. Eg:
+    #
+    #   refute_operator 1, :>, 2 #=> pass
+    #   refute_operator 1, :<, 2 #=> fail
+
+    def refute_operator o1, op, o2 = (predicate = true; nil), msg = nil
+      return refute_predicate o1, op, msg if predicate
+      msg = message(msg) { "Expected #{mu_pp(o1)} to not be #{op} #{mu_pp(o2)}"}
+      refute o1.__send__(op, o2), msg
+    end
+
+    ##
+    # For testing with predicates.
+    #
+    #   refute_predicate str, :empty?
+    #
+    # This is really meant for specs and is front-ended by refute_operator:
+    #
+    #   str.wont_be :empty?
+
+    def refute_predicate o1, op, msg = nil
+      msg = message(msg) { "Expected #{mu_pp(o1)} to not be #{op}" }
+      refute o1.__send__(op), msg
+    end
+
+    ##
+    # Fails if +obj+ responds to the message +meth+.
+
+    def refute_respond_to obj, meth, msg = nil
+      msg = message(msg) { "Expected #{mu_pp(obj)} to not respond to #{meth}" }
+
+      refute obj.respond_to?(meth), msg
+    end
+
+    ##
+    # Fails if +exp+ is the same (by object identity) as +act+.
+
+    def refute_same exp, act, msg = nil
+      msg = message(msg) {
+        data = [mu_pp(act), act.object_id, mu_pp(exp), exp.object_id]
+        "Expected %s (oid=%d) to not be the same as %s (oid=%d)" % data
+      }
+      refute exp.equal?(act), msg
+    end
+
+    ##
+    # Skips the current test. Gets listed at the end of the run but
+    # doesn't cause a failure exit code.
+
+    def skip msg = nil, bt = caller
+      msg ||= "Skipped, no message given"
+      @skip = true
+      raise MiniTest::Skip, msg, bt
+    end
+
+    ##
+    # Was this testcase skipped? Meant for #teardown.
+
+    def skipped?
+      defined?(@skip) and @skip
+    end
+
+    ##
+    # Takes a block and wraps it with the runner's shared mutex.
+
+    def synchronize
+      Minitest::Unit.runner.synchronize do
+        yield
+      end
+    end
+  end
+
+  class Unit # :nodoc:
+    VERSION = "4.7.5" # :nodoc:
+
+    attr_accessor :report, :failures, :errors, :skips # :nodoc:
+    attr_accessor :assertion_count                    # :nodoc:
+    attr_writer   :test_count                         # :nodoc:
+    attr_accessor :start_time                         # :nodoc:
+    attr_accessor :help                               # :nodoc:
+    attr_accessor :verbose                            # :nodoc:
+    attr_writer   :options                            # :nodoc:
+
+    ##
+    # :attr:
+    #
+    # if true, installs an "INFO" signal handler (only available to BSD and
+    # OS X users) which prints diagnostic information about the test run.
+    #
+    # This is auto-detected by default but may be overridden by custom
+    # runners.
+
+    attr_accessor :info_signal
+
+    ##
+    # Lazy accessor for options.
+
+    def options
+      @options ||= {}
+    end
+
+    @@installed_at_exit ||= false
+    @@out = $stdout
+    @@after_tests = []
+
+    ##
+    # A simple hook allowing you to run a block of code after _all_ of
+    # the tests are done. Eg:
+    #
+    #   MiniTest::Unit.after_tests { p $debugging_info }
+
+    def self.after_tests &block
+      @@after_tests << block
+    end
+
+    ##
+    # Registers MiniTest::Unit to run tests at process exit
+
+    def self.autorun
+      at_exit {
+        # don't run if there was a non-exit exception
+        next if $! and not $!.kind_of? SystemExit
+
+        # the order here is important. The at_exit handler must be
+        # installed before anyone else gets a chance to install their
+        # own, that way we can be assured that our exit will be last
+        # to run (at_exit stacks).
+        exit_code = nil
+
+        at_exit {
+          @@after_tests.reverse_each(&:call)
+          exit false if exit_code && exit_code != 0
+        }
+
+        exit_code = MiniTest::Unit.new.run ARGV
+      } unless @@installed_at_exit
+      @@installed_at_exit = true
+    end
+
+    ##
+    # Returns the stream to use for output.
+
+    def self.output
+      @@out
+    end
+
+    ##
+    # Sets MiniTest::Unit to write output to +stream+.  $stdout is the default
+    # output
+
+    def self.output= stream
+      @@out = stream
+    end
+
+    ##
+    # Tells MiniTest::Unit to delegate to +runner+, an instance of a
+    # MiniTest::Unit subclass, when MiniTest::Unit#run is called.
+
+    def self.runner= runner
+      @@runner = runner
+    end
+
+    ##
+    # Returns the MiniTest::Unit subclass instance that will be used
+    # to run the tests. A MiniTest::Unit instance is the default
+    # runner.
+
+    def self.runner
+      @@runner ||= self.new
+    end
+
+    ##
+    # Return all plugins' run methods (methods that start with "run_").
+
+    def self.plugins
+      @@plugins ||= (["run_tests"] +
+                     public_instance_methods(false).
+                     grep(/^run_/).map { |s| s.to_s }).uniq
+    end
+
+    ##
+    # Return the IO for output.
+
+    def output
+      self.class.output
+    end
+
+    def puts *a  # :nodoc:
+      output.puts(*a)
+    end
+
+    def print *a # :nodoc:
+      output.print(*a)
+    end
+
+    def test_count # :nodoc:
+      @test_count ||= 0
+    end
+
+    ##
+    # Runner for a given +type+ (eg, test vs bench).
+
+    def _run_anything type
+      suites = TestCase.send "#{type}_suites"
+      return if suites.empty?
+
+      puts
+      puts "# Running #{type}s:"
+      puts
+
+      @test_count, @assertion_count = 0, 0
+      test_count = assertion_count = 0
+      sync = output.respond_to? :"sync=" # stupid emacs
+      old_sync, output.sync = output.sync, true if sync
+
+      count = 0
+      begin
+        start = Time.now
+
+        results = _run_suites suites, type
+
+        @test_count      = results.inject(0) { |sum, (tc, _)| sum + tc }
+        @assertion_count = results.inject(0) { |sum, (_, ac)| sum + ac }
+        test_count      += @test_count
+        assertion_count += @assertion_count
+        t = Time.now - start
+        count += 1
+        unless @repeat_count
+          puts
+          puts
+        end
+        puts "Finished%s %ss in %.6fs, %.4f tests/s, %.4f assertions/s.\n" %
+             [(@repeat_count ? "(#{count}/#{@repeat_count}) " : ""), type,
+               t, @test_count.fdiv(t), @assertion_count.fdiv(t)]
+      end while @repeat_count && count < @repeat_count &&
+                report.empty? && failures.zero? && errors.zero?
+
+      output.sync = old_sync if sync
+
+      report.each_with_index do |msg, i|
+        puts "\n%3d) %s" % [i + 1, msg]
+      end
+
+      puts
+      @test_count      = test_count
+      @assertion_count = assertion_count
+
+      status
+    end
+
+    ##
+    # Runs all the +suites+ for a given +type+.
+    #
+
+    def _run_suites suites, type
+      suites.map { |suite| _run_suite suite, type }
+    end
+
+    ##
+    # Run a single +suite+ for a given +type+.
+
+    def _run_suite suite, type
+      header = "#{type}_suite_header"
+      puts send(header, suite) if respond_to? header
+
+      filter = options[:filter] || '/./'
+      filter = Regexp.new $1 if filter =~ /\/(.*)\//
+
+      all_test_methods = suite.send "#{type}_methods"
+
+      filtered_test_methods = all_test_methods.find_all { |m|
+        filter === m || filter === "#{suite}##{m}"
+      }
+
+      leakchecker = LeakChecker.new
+
+      assertions = filtered_test_methods.map { |method|
+        inst = suite.new method
+        inst._assertions = 0
+
+        print "#{suite}##{method} = " if @verbose
+
+        start_time = Time.now if @verbose
+        result = inst.run self
+
+        print "%.2f s = " % (Time.now - start_time) if @verbose
+        print result
+        puts if @verbose
+        $stdout.flush
+
+        unless defined?(RubyVM::MJIT) && RubyVM::MJIT.enabled? # compiler process is wrongly considered as leak
+          leakchecker.check("#{inst.class}\##{inst.__name__}")
+        end
+
+        inst._assertions
+      }
+
+      return assertions.size, assertions.inject(0) { |sum, n| sum + n }
+    end
+
+    ##
+    # Record the result of a single test. Makes it very easy to gather
+    # information. Eg:
+    #
+    #   class StatisticsRecorder < MiniTest::Unit
+    #     def record suite, method, assertions, time, error
+    #       # ... record the results somewhere ...
+    #     end
+    #   end
+    #
+    #   MiniTest::Unit.runner = StatisticsRecorder.new
+    #
+    # NOTE: record might be sent more than once per test.  It will be
+    # sent once with the results from the test itself.  If there is a
+    # failure or error in teardown, it will be sent again with the
+    # error or failure.
+
+    def record suite, method, assertions, time, error
+    end
+
+    def location e # :nodoc:
+      last_before_assertion = ""
+      e.backtrace.reverse_each do |s|
+        break if s =~ /in .(assert|refute|flunk|pass|fail|raise|must|wont)/
+        last_before_assertion = s
+      end
+      last_before_assertion.sub(/:in .*$/, '')
+    end
+
+    ##
+    # Writes status for failed test +meth+ in +klass+ which finished with
+    # exception +e+
+
+    def puke klass, meth, e
+      e = case e
+          when MiniTest::Skip then
+            @skips += 1
+            return "S" unless @verbose
+            "Skipped:\n#{klass}##{meth} [#{location e}]:\n#{e.message}\n"
+          when MiniTest::Assertion then
+            @failures += 1
+            "Failure:\n#{klass}##{meth} [#{location e}]:\n#{e.message}\n"
+          else
+            @errors += 1
+            bt = MiniTest::filter_backtrace(e.backtrace).join "\n    "
+            "Error:\n#{klass}##{meth}:\n#{e.class}: #{e.message.b}\n    #{bt}\n"
+          end
+      @report << e
+      e[0, 1]
+    end
+
+    def initialize # :nodoc:
+      @report = []
+      @errors = @failures = @skips = 0
+      @verbose = false
+      @mutex = Thread::Mutex.new
+      @info_signal = Signal.list['INFO']
+      @repeat_count = nil
+    end
+
+    def synchronize # :nodoc:
+      if @mutex then
+        @mutex.synchronize { yield }
+      else
+        yield
+      end
+    end
+
+    def process_args args = [] # :nodoc:
+      options = {}
+      orig_args = args.dup
+
+      OptionParser.new do |opts|
+        opts.banner  = 'minitest options:'
+        opts.version = MiniTest::Unit::VERSION
+
+        opts.on '-h', '--help', 'Display this help.' do
+          puts opts
+          exit
+        end
+
+        opts.on '-s', '--seed SEED', Integer, "Sets random seed" do |m|
+          options[:seed] = m.to_i
+        end
+
+        opts.on '-v', '--verbose', "Verbose. Show progress processing files." do
+          options[:verbose] = true
+        end
+
+        opts.on '-n', '--name PATTERN', "Filter test names on pattern (e.g. /foo/)" do |a|
+          options[:filter] = a
+        end
+
+        opts.parse! args
+        orig_args -= args
+      end
+
+      unless options[:seed] then
+        srand
+        options[:seed] = srand % 0xFFFF
+        orig_args << "--seed" << options[:seed].to_s
+      end
+
+      srand options[:seed]
+
+      self.verbose = options[:verbose]
+      @help = orig_args.map { |s| s =~ /[\s|&<>$()]/ ? s.inspect : s }.join " "
+
+      options
+    end
+
+    ##
+    # Begins the full test run. Delegates to +runner+'s #_run method.
+
+    def run args = []
+      self.class.runner._run(args)
+    end
+
+    ##
+    # Top level driver, controls all output and filtering.
+
+    def _run args = []
+      args = process_args args # ARGH!! blame test/unit process_args
+      self.options.merge! args
+
+      puts "Run options: #{help}"
+
+      self.class.plugins.each do |plugin|
+        send plugin
+        break unless report.empty?
+      end
+
+      return failures + errors if self.test_count > 0 # or return nil...
+    rescue Interrupt
+      abort 'Interrupted'
+    end
+
+    ##
+    # Runs test suites matching +filter+.
+
+    def run_tests
+      _run_anything :test
+    end
+
+    ##
+    # Writes status to +io+
+
+    def status io = self.output
+      format = "%d tests, %d assertions, %d failures, %d errors, %d skips"
+      io.puts format % [test_count, assertion_count, failures, errors, skips]
+    end
+
+    ##
+    # Provides a simple set of guards that you can use in your tests
+    # to skip execution if it is not applicable. These methods are
+    # mixed into TestCase as both instance and class methods so you
+    # can use them inside or outside of the test methods.
+    #
+    #   def test_something_for_mri
+    #     skip "bug 1234"  if jruby?
+    #     # ...
+    #   end
+    #
+    #   if windows? then
+    #     # ... lots of test methods ...
+    #   end
+
+    module Guard
+
+      ##
+      # Is this running on jruby?
+
+      def jruby? platform = RUBY_PLATFORM
+        "java" == platform
+      end
+
+      ##
+      # Is this running on mri?
+
+      def maglev? platform = defined?(RUBY_ENGINE) && RUBY_ENGINE
+        "maglev" == platform
+      end
+
+      module_function :maglev?
+
+      ##
+      # Is this running on mri?
+
+      def mri? platform = RUBY_DESCRIPTION
+        /^ruby/ =~ platform
+      end
+
+      ##
+      # Is this running on rubinius?
+
+      def rubinius? platform = defined?(RUBY_ENGINE) && RUBY_ENGINE
+        "rbx" == platform
+      end
+
+      ##
+      # Is this running on windows?
+
+      def windows? platform = RUBY_PLATFORM
+        /mswin|mingw/ =~ platform
+      end
+
+      ##
+      # Is this running on mingw?
+
+      def mingw? platform = RUBY_PLATFORM
+        /mingw/ =~ platform
+      end
+
+    end
+
+    ##
+    # Provides before/after hooks for setup and teardown. These are
+    # meant for library writers, NOT for regular test authors. See
+    # #before_setup for an example.
+
+    module LifecycleHooks
+      ##
+      # Runs before every test, after setup. This hook is meant for
+      # libraries to extend minitest. It is not meant to be used by
+      # test developers.
+      #
+      # See #before_setup for an example.
+
+      def after_setup; end
+
+      ##
+      # Runs before every test, before setup. This hook is meant for
+      # libraries to extend minitest. It is not meant to be used by
+      # test developers.
+      #
+      # As a simplistic example:
+      #
+      #   module MyMinitestPlugin
+      #     def before_setup
+      #       super
+      #       # ... stuff to do before setup is run
+      #     end
+      #
+      #     def after_setup
+      #       # ... stuff to do after setup is run
+      #       super
+      #     end
+      #
+      #     def before_teardown
+      #       super
+      #       # ... stuff to do before teardown is run
+      #     end
+      #
+      #     def after_teardown
+      #       # ... stuff to do after teardown is run
+      #       super
+      #     end
+      #   end
+      #
+      #   class MiniTest::Unit::TestCase
+      #     include MyMinitestPlugin
+      #   end
+
+      def before_setup; end
+
+      ##
+      # Runs after every test, before teardown. This hook is meant for
+      # libraries to extend minitest. It is not meant to be used by
+      # test developers.
+      #
+      # See #before_setup for an example.
+
+      def before_teardown; end
+
+      ##
+      # Runs after every test, after teardown. This hook is meant for
+      # libraries to extend minitest. It is not meant to be used by
+      # test developers.
+      #
+      # See #before_setup for an example.
+
+      def after_teardown; end
+    end
+
+    ##
+    # Subclass TestCase to create your own tests. Typically you'll want a
+    # TestCase subclass per implementation class.
+    #
+    # See MiniTest::Assertions
+
+    class TestCase
+      include LifecycleHooks
+      include Guard
+      extend Guard
+
+      attr_reader :__name__ # :nodoc:
+
+      PASSTHROUGH_EXCEPTIONS = [NoMemoryError, SignalException,
+                                Interrupt, SystemExit] # :nodoc:
+
+      ##
+      # Runs the tests reporting the status to +runner+
+
+      def run runner
+        trap "INFO" do
+          runner.report.each_with_index do |msg, i|
+            warn "\n%3d) %s" % [i + 1, msg]
+          end
+          warn ''
+          time = runner.start_time ? Time.now - runner.start_time : 0
+          warn "Current Test: %s#%s %.2fs" % [self.class, self.__name__, time]
+          runner.status $stderr
+        end if runner.info_signal
+
+        start_time = Time.now
+
+        result = ""
+        begin
+          @passed = nil
+          self.before_setup
+          self.setup
+          self.after_setup
+          self.run_test self.__name__
+          result = "." unless io?
+          time = Time.now - start_time
+          runner.record self.class, self.__name__, self._assertions, time, nil
+          @passed = true
+        rescue *PASSTHROUGH_EXCEPTIONS
+          raise
+        rescue Exception => e
+          @passed = Skip === e
+          time = Time.now - start_time
+          runner.record self.class, self.__name__, self._assertions, time, e
+          result = runner.puke self.class, self.__name__, e
+        ensure
+          %w{ before_teardown teardown after_teardown }.each do |hook|
+            begin
+              self.send hook
+            rescue *PASSTHROUGH_EXCEPTIONS
+              raise
+            rescue Exception => e
+              @passed = false
+              runner.record self.class, self.__name__, self._assertions, time, e
+              result = runner.puke self.class, self.__name__, e
+            end
+          end
+          trap 'INFO', 'DEFAULT' if runner.info_signal
+        end
+        result
+      end
+
+      alias :run_test :__send__
+
+      def initialize name # :nodoc:
+        @__name__ = name
+        @__io__ = nil
+        @passed = nil
+        @@current = self # FIX: make thread local
+      end
+
+      def self.current # :nodoc:
+        @@current # FIX: make thread local
+      end
+
+      ##
+      # Return the output IO object
+
+      def io
+        @__io__ = true
+        MiniTest::Unit.output
+      end
+
+      ##
+      # Have we hooked up the IO yet?
+
+      def io?
+        @__io__
+      end
+
+      def self.reset # :nodoc:
+        @@test_suites = {}
+      end
+
+      reset
+
+      ##
+      # Make diffs for this TestCase use #pretty_inspect so that diff
+      # in assert_equal can be more details. NOTE: this is much slower
+      # than the regular inspect but much more usable for complex
+      # objects.
+
+      def self.make_my_diffs_pretty!
+        require 'pp'
+
+        define_method :mu_pp do |o|
+          o.pretty_inspect
+        end
+      end
+
+      def self.inherited klass # :nodoc:
+        @@test_suites[klass] = true
+        super
+      end
+
+      def self.test_order # :nodoc:
+        :random
+      end
+
+      def self.test_suites # :nodoc:
+        @@test_suites.keys.sort_by { |ts| ts.name.to_s }
+      end
+
+      def self.test_methods # :nodoc:
+        methods = public_instance_methods(true).grep(/^test/).map { |m| m.to_s }
+
+        case self.test_order
+        when :parallel
+          max = methods.size
+          ParallelEach.new methods.sort.sort_by { rand max }
+        when :random then
+          max = methods.size
+          methods.sort.sort_by { rand max }
+        when :alpha, :sorted then
+          methods.sort
+        else
+          raise "Unknown test_order: #{self.test_order.inspect}"
+        end
+      end
+
+      ##
+      # Returns true if the test passed.
+
+      def passed?
+        @passed
+      end
+
+      ##
+      # Runs before every test. Use this to set up before each test
+      # run.
+
+      def setup; end
+
+      ##
+      # Runs after every test. Use this to clean up after each test
+      # run.
+
+      def teardown; end
+
+      include MiniTest::Assertions
+    end # class TestCase
+  end # class Unit
+
+  Test = Unit::TestCase
+end # module MiniTest
+
+Minitest = MiniTest # :nodoc: because ugh... I typo this all the time
diff --git a/tool/lib/profile_test_all.rb b/tool/lib/profile_test_all.rb
new file mode 100644
index 0000000000..2c360d76dd
--- /dev/null
+++ b/tool/lib/profile_test_all.rb
@@ -0,0 +1,91 @@
+# frozen_string_literal: true
+#
+# purpose:
+#  Profile memory usage of each tests.
+#
+# usage:
+#   RUBY_TEST_ALL_PROFILE=[file] make test-all
+#
+# output:
+#   [file] specified by RUBY_TEST_ALL_PROFILE
+#   If [file] is 'true', then it is ./test_all_profile
+#
+# collected information:
+#   - ObjectSpace.memsize_of_all
+#   - GC.stat
+#   - /proc/meminfo     (some fields, if exists)
+#   - /proc/self/status (some fields, if exists)
+#   - /proc/self/statm  (if exists)
+#
+
+require 'objspace'
+
+class MiniTest::Unit::TestCase
+  alias orig_run run
+
+  file = ENV['RUBY_TEST_ALL_PROFILE']
+  file = 'test-all-profile-result' if file == 'true'
+  TEST_ALL_PROFILE_OUT = open(file, 'w')
+  TEST_ALL_PROFILE_GC_STAT_HASH = {}
+  TEST_ALL_PROFILE_BANNER = ['name']
+  TEST_ALL_PROFILE_PROCS  = []
+
+  def self.add *name, &b
+    TEST_ALL_PROFILE_BANNER.concat name
+    TEST_ALL_PROFILE_PROCS << b
+  end
+
+  add 'failed?' do |result, tc|
+    result << (tc.passed? ? 0 : 1)
+  end
+
+  add 'memsize_of_all' do |result, *|
+    result << ObjectSpace.memsize_of_all
+  end
+
+  add(*GC.stat.keys) do |result, *|
+    GC.stat(TEST_ALL_PROFILE_GC_STAT_HASH)
+    result.concat TEST_ALL_PROFILE_GC_STAT_HASH.values
+  end
+
+  def self.add_proc_meminfo file, fields
+    return unless FileTest.exist?(file)
+    regexp = /(#{fields.join("|")}):\s*(\d+) kB/
+    # check = {}; fields.each{|e| check[e] = true}
+    add(*fields) do |result, *|
+      text = File.read(file)
+      text.scan(regexp){
+        # check.delete $1
+        result << $2
+        ''
+      }
+      # raise check.inspect unless check.empty?
+    end
+  end
+
+  add_proc_meminfo '/proc/meminfo', %w(MemTotal MemFree)
+  add_proc_meminfo '/proc/self/status', %w(VmPeak VmSize VmHWM VmRSS)
+
+  if FileTest.exist?('/proc/self/statm')
+    add 'size', 'resident', 'share', 'text', 'lib', 'data', 'dt' do |result, *|
+      result.concat File.read('/proc/self/statm').split(/\s+/)
+    end
+  end
+
+  def memprofile_test_all_result_result
+    result = ["#{self.class}\##{self.__name__.to_s.gsub(/\s+/, '')}"]
+    TEST_ALL_PROFILE_PROCS.each{|proc|
+      proc.call(result, self)
+    }
+    result.join("\t")
+  end
+
+  def run runner
+    result = orig_run(runner)
+    TEST_ALL_PROFILE_OUT.puts memprofile_test_all_result_result
+    TEST_ALL_PROFILE_OUT.flush
+    result
+  end
+
+  TEST_ALL_PROFILE_OUT.puts TEST_ALL_PROFILE_BANNER.join("\t")
+end
diff --git a/tool/lib/test/unit.rb b/tool/lib/test/unit.rb
new file mode 100644
index 0000000000..3df6774d61
--- /dev/null
+++ b/tool/lib/test/unit.rb
@@ -0,0 +1,1175 @@
+# frozen_string_literal: true
+begin
+  gem 'minitest', '< 5.0.0' if defined? Gem
+rescue Gem::LoadError
+end
+require 'minitest/unit'
+require 'test/unit/assertions'
+require_relative '../envutil'
+require_relative '../../../tool/colorize'
+require 'test/unit/testcase'
+require 'optparse'
+
+# See Test::Unit
+module Test
+  ##
+  # Test::Unit is an implementation of the xUnit testing framework for Ruby.
+  #
+  # If you are writing new test code, please use MiniTest instead of Test::Unit.
+  #
+  # Test::Unit has been left in the standard library to support legacy test
+  # suites.
+  module Unit
+    TEST_UNIT_IMPLEMENTATION = 'test/unit compatibility layer using minitest' # :nodoc:
+
+    module RunCount # :nodoc: all
+      @@run_count = 0
+
+      def self.have_run?
+        @@run_count.nonzero?
+      end
+
+      def run(*)
+        @@run_count += 1
+        super
+      end
+
+      def run_once
+        return if have_run?
+        return if $! # don't run if there was an exception
+        yield
+      end
+      module_function :run_once
+    end
+
+    module Options # :nodoc: all
+      def initialize(*, &block)
+        @init_hook = block
+        @options = nil
+        super(&nil)
+      end
+
+      def option_parser
+        @option_parser ||= OptionParser.new
+      end
+
+      def process_args(args = [])
+        return @options if @options
+        orig_args = args.dup
+        options = {}
+        opts = option_parser
+        setup_options(opts, options)
+        opts.parse!(args)
+        orig_args -= args
+        args = @init_hook.call(args, options) if @init_hook
+        non_options(args, options)
+        @run_options = orig_args
+        @help = orig_args.map { |s| s =~ /[\s|&<>$()]/ ? s.inspect : s }.join " "
+        @options = options
+      end
+
+      private
+      def setup_options(opts, options)
+        opts.separator 'minitest options:'
+        opts.version = MiniTest::Unit::VERSION
+
+        opts.on '-h', '--help', 'Display this help.' do
+          puts opts
+          exit
+        end
+
+        opts.on '-s', '--seed SEED', Integer, "Sets random seed" do |m|
+          options[:seed] = m
+        end
+
+        opts.on '-v', '--verbose', "Verbose. Show progress processing files." do
+          options[:verbose] = true
+          self.verbose = options[:verbose]
+        end
+
+        opts.on '-n', '--name PATTERN', "Filter test method names on pattern: /REGEXP/, !/REGEXP/ or STRING" do |a|
+          (options[:filter] ||= []) << a
+        end
+
+        opts.on '--test-order=random|alpha|sorted', [:random, :alpha, :sorted] do |a|
+          MiniTest::Unit::TestCase.test_order = a
+        end
+      end
+
+      def non_options(files, options)
+        filter = options[:filter]
+        if filter
+          pos_pat = /\A\/(.*)\/\z/
+          neg_pat = /\A!\/(.*)\/\z/
+          negative, positive = filter.partition {|s| neg_pat =~ s}
+          if positive.empty?
+            filter = nil
+          elsif negative.empty? and positive.size == 1 and pos_pat !~ positive[0]
+            filter = positive[0]
+          else
+            filter = Regexp.union(*positive.map! {|s| Regexp.new(s[pos_pat, 1] || "\\A#{Regexp.quote(s)}\\z")})
+          end
+          unless negative.empty?
+            negative = Regexp.union(*negative.map! {|s| Regexp.new(s[neg_pat, 1])})
+            filter = /\A(?=.*#{filter})(?!.*#{negative})/
+          end
+          if Regexp === filter
+            # bypass conversion in minitest
+            def filter.=~(other)    # :nodoc:
+              super unless Regexp === other
+            end
+          end
+          options[:filter] = filter
+        end
+        true
+      end
+    end
+
+    module Parallel # :nodoc: all
+      def process_args(args = [])
+        return @options if @options
+        options = super
+        if @options[:parallel]
+          @files = args
+        end
+        options
+      end
+
+      def non_options(files, options)
+        @jobserver = nil
+        makeflags = ENV.delete("MAKEFLAGS")
+        if !options[:parallel] and
+          /(?:\A|\s)--jobserver-(?:auth|fds)=(\d+),(\d+)/ =~ makeflags
+          begin
+            r = IO.for_fd($1.to_i(10), "rb", autoclose: false)
+            w = IO.for_fd($2.to_i(10), "wb", autoclose: false)
+          rescue
+            r.close if r
+            nil
+          else
+            r.close_on_exec = true
+            w.close_on_exec = true
+            @jobserver = [r, w]
+            options[:parallel] ||= 1
+          end
+        end
+        super
+      end
+
+      def status(*args)
+        result = super
+        raise @interrupt if @interrupt
+        result
+      end
+
+      private
+      def setup_options(opts, options)
+        super
+
+        opts.separator "parallel test options:"
+
+        options[:retry] = true
+
+        opts.on '-j N', '--jobs N', /\A(t)?(\d+)\z/, "Allow run tests with N jobs at once" do |_, t, a|
+          options[:testing] = true & t # For testing
+          options[:parallel] = a.to_i
+        end
+
+        opts.on '--separate', "Restart job process after one testcase has done" do
+          options[:parallel] ||= 1
+          options[:separate] = true
+        end
+
+        opts.on '--retry', "Retry running testcase when --jobs specified" do
+          options[:retry] = true
+        end
+
+        opts.on '--no-retry', "Disable --retry" do
+          options[:retry] = false
+        end
+
+        opts.on '--ruby VAL', "Path to ruby which is used at -j option" do |a|
+          options[:ruby] = a.split(/ /).reject(&:empty?)
+        end
+      end
+
+      class Worker
+        def self.launch(ruby,args=[])
+          scale = EnvUtil.timeout_scale
+          io = IO.popen([*ruby, "-W1",
+                        "#{File.dirname(__FILE__)}/unit/parallel.rb",
+                        *("--timeout-scale=#{scale}" if scale),
+                        *args], "rb+")
+          new(io, io.pid, :waiting)
+        end
+
+        attr_reader :quit_called
+
+        def initialize(io, pid, status)
+          @io = io
+          @pid = pid
+          @status = status
+          @file = nil
+          @real_file = nil
+          @loadpath = []
+          @hooks = {}
+          @quit_called = false
+        end
+
+        def puts(*args)
+          @io.puts(*args)
+        end
+
+        def run(task,type)
+          @file = File.basename(task, ".rb")
+          @real_file = task
+          begin
+            puts "loadpath #{[Marshal.dump($:-@loadpath)].pack("m0")}"
+            @loadpath = $:.dup
+            puts "run #{task} #{type}"
+            @status = :prepare
+          rescue Errno::EPIPE
+            died
+          rescue IOError
+            raise unless /stream closed|closed stream/ =~ $!.message
+            died
+          end
+        end
+
+        def hook(id,&block)
+          @hooks[id] ||= []
+          @hooks[id] << block
+          self
+        end
+
+        def read
+          res = (@status == :quit) ? @io.read : @io.gets
+          res && res.chomp
+        end
+
+        def close
+          @io.close unless @io.closed?
+          self
+        rescue IOError
+        end
+
+        def quit
+          return if @io.closed?
+          @quit_called = true
+          @io.puts "quit"
+        rescue Errno::EPIPE => e
+          warn "#{@pid}:#{@status.to_s.ljust(7)}:#{@file}: #{e.message}"
+        end
+
+        def kill
+          Process.kill(:KILL, @pid)
+        rescue Errno::ESRCH
+        end
+
+        def died(*additional)
+          @status = :quit
+          @io.close
+          status = $?
+          if status and status.signaled?
+            additional[0] ||= SignalException.new(status.termsig)
+          end
+
+          call_hook(:dead,*additional)
+        end
+
+        def to_s
+          if @file and @status != :ready
+            "#{@pid}=#{@file}"
+          else
+            "#{@pid}:#{@status.to_s.ljust(7)}"
+          end
+        end
+
+        attr_reader :io, :pid
+        attr_accessor :status, :file, :real_file, :loadpath
+
+        private
+
+        def call_hook(id,*additional)
+          @hooks[id] ||= []
+          @hooks[id].each{|hook| hook[self,additional] }
+          self
+        end
+
+      end
+
+      def flush_job_tokens
+        if @jobserver
+          r, w = @jobserver.shift(2)
+          @jobserver = nil
+          w << @job_tokens.slice!(0..-1)
+          r.close
+          w.close
+        end
+      end
+
+      def after_worker_down(worker, e=nil, c=false)
+        return unless @options[:parallel]
+        return if @interrupt
+        flush_job_tokens
+        warn e if e
+        real_file = worker.real_file and warn "running file: #{real_file}"
+        @need_quit = true
+        warn ""
+        warn "Some worker was crashed. It seems ruby interpreter's bug"
+        warn "or, a bug of test/unit/parallel.rb. try again without -j"
+        warn "option."
+        warn ""
+        STDERR.flush
+        exit c
+      end
+
+      def after_worker_quit(worker)
+        return unless @options[:parallel]
+        return if @interrupt
+        worker.close
+        if @jobserver and (token = @job_tokens.slice!(0))
+          @jobserver[1] << token
+        end
+        @workers.delete(worker)
+        @dead_workers << worker
+        @ios = @workers.map(&:io)
+      end
+
+      def launch_worker
+        begin
+          worker = Worker.launch(@options[:ruby], @run_options)
+        rescue => e
+          abort "ERROR: Failed to launch job process - #{e.class}: #{e.message}"
+        end
+        worker.hook(:dead) do |w,info|
+          after_worker_quit w
+          after_worker_down w, *info if !info.empty? && !worker.quit_called
+        end
+        @workers << worker
+        @ios << worker.io
+        @workers_hash[worker.io] = worker
+        worker
+      end
+
+      def delete_worker(worker)
+        @workers_hash.delete worker.io
+        @workers.delete worker
+        @ios.delete worker.io
+      end
+
+      def quit_workers
+        return if @workers.empty?
+        @workers.reject! do |worker|
+          begin
+            Timeout.timeout(1) do
+              worker.quit
+            end
+          rescue Errno::EPIPE
+          rescue Timeout::Error
+          end
+          worker.close
+        end
+
+        return if @workers.empty?
+        begin
+          Timeout.timeout(0.2 * @workers.size) do
+            Process.waitall
+          end
+        rescue Timeout::Error
+          @workers.each do |worker|
+            worker.kill
+          end
+          @worker.clear
+        end
+      end
+
+      FakeClass = Struct.new(:name)
+      def fake_class(name)
+        (@fake_classes ||= {})[name] ||= FakeClass.new(name)
+      end
+
+      def deal(io, type, result, rep, shutting_down = false)
+        worker = @workers_hash[io]
+        cmd = worker.read
+        cmd.sub!(/\A\.+/, '') if cmd # read may return nil
+        case cmd
+        when ''
+          # just only dots, ignore
+        when /^okay$/
+          worker.status = :running
+        when /^ready(!)?$/
+          bang = $1
+          worker.status = :ready
+
+          unless task = @tasks.shift
+            worker.quit
+            return nil
+          end
+          if @options[:separate] and not bang
+            worker.quit
+            worker = launch_worker
+          end
+          worker.run(task, type)
+          @test_count += 1
+
+          jobs_status(worker)
+        when /^done (.+?)$/
+          begin
+            r = Marshal.load($1.unpack("m")[0])
+          rescue
+            print "unknown object: #{$1.unpack("m")[0].dump}"
+            return true
+          end
+          result << r[0..1] unless r[0..1] == [nil,nil]
+          rep    << {file: worker.real_file, report: r[2], result: r[3], testcase: r[5]}
+          $:.push(*r[4]).uniq!
+          jobs_status(worker) if @options[:job_status] == :replace
+          return true
+        when /^record (.+?)$/
+          begin
+            r = Marshal.load($1.unpack("m")[0])
+          rescue => e
+            print "unknown record: #{e.message} #{$1.unpack("m")[0].dump}"
+            return true
+          end
+          record(fake_class(r[0]), *r[1..-1])
+        when /^p (.+?)$/
+          del_jobs_status
+          print $1.unpack("m")[0]
+          jobs_status(worker) if @options[:job_status] == :replace
+        when /^after (.+?)$/
+          @warnings << Marshal.load($1.unpack("m")[0])
+        when /^bye (.+?)$/
+          after_worker_down worker, Marshal.load($1.unpack("m")[0])
+        when /^bye$/, nil
+          if shutting_down || worker.quit_called
+            after_worker_quit worker
+          else
+            after_worker_down worker
+          end
+        else
+          print "unknown command: #{cmd.dump}\n"
+        end
+        return false
+      end
+
+      def _run_parallel suites, type, result
+        if @options[:parallel] < 1
+          warn "Error: parameter of -j option should be greater than 0."
+          return
+        end
+
+        # Require needed thing for parallel running
+        require 'timeout'
+        @tasks = @files.dup # Array of filenames.
+        @need_quit = false
+        @dead_workers = []  # Array of dead workers.
+        @warnings = []
+        @total_tests = @tasks.size.to_s(10)
+        rep = [] # FIXME: more good naming
+
+        @workers      = [] # Array of workers.
+        @workers_hash = {} # out-IO => worker
+        @ios          = [] # Array of worker IOs
+        @job_tokens   = String.new(encoding: Encoding::ASCII_8BIT) if @jobserver
+        begin
+          [@tasks.size, @options[:parallel]].min.times {launch_worker}
+
+          while _io = IO.select(@ios)[0]
+            break if _io.any? do |io|
+              @need_quit or
+                (deal(io, type, result, rep).nil? and
+                 !@workers.any? {|x| [:running, :prepare].include? x.status})
+            end
+            if @jobserver and @job_tokens and !@tasks.empty? and !@workers.any? {|x| x.status == :ready}
+              t = @jobserver[0].read_nonblock([@tasks.size, @options[:parallel]].min, exception: false)
+              if String === t
+                @job_tokens << t
+                t.size.times {launch_worker}
+              end
+            end
+          end
+        rescue Interrupt => ex
+          @interrupt = ex
+          return result
+        ensure
+          if @interrupt
+            @ios.select!{|x| @workers_hash[x].status == :running }
+            while !@ios.empty? && (__io = IO.select(@ios,[],[],10))
+              __io[0].reject! {|io| deal(io, type, result, rep, true)}
+            end
+          end
+
+          quit_workers
+          flush_job_tokens
+
+          unless @interrupt || !@options[:retry] || @need_quit
+            parallel = @options[:parallel]
+            @options[:parallel] = false
+            suites, rep = rep.partition {|r| r[:testcase] && r[:file] && r[:report].any? {|e| !e[2].is_a?(MiniTest::Skip)}}
+            suites.map {|r| r[:file]}.uniq.each {|file| require file}
+            suites.map! {|r| eval("::"+r[:testcase])}
+            del_status_line or puts
+            unless suites.empty?
+              puts "\n""Retrying..."
+              _run_suites(suites, type)
+            end
+            @options[:parallel] = parallel
+          end
+          unless @options[:retry]
+            del_status_line or puts
+          end
+          unless rep.empty?
+            rep.each do |r|
+              r[:report].each do |f|
+                puke(*f) if f
+              end
+            end
+            if @options[:retry]
+              @errors   += rep.map{|x| x[:result][0] }.inject(:+)
+              @failures += rep.map{|x| x[:result][1] }.inject(:+)
+              @skips    += rep.map{|x| x[:result][2] }.inject(:+)
+            end
+          end
+          unless @warnings.empty?
+            warn ""
+            @warnings.uniq! {|w| w[1].message}
+            @warnings.each do |w|
+              warn "#{w[0]}: #{w[1].message} (#{w[1].class})"
+            end
+            warn ""
+          end
+        end
+      end
+
+      def _run_suites suites, type
+        _prepare_run(suites, type)
+        @interrupt = nil
+        result = []
+        GC.start
+        if @options[:parallel]
+          _run_parallel suites, type, result
+        else
+          suites.each {|suite|
+            begin
+              result << _run_suite(suite, type)
+            rescue Interrupt => e
+              @interrupt = e
+              break
+            end
+          }
+        end
+        del_status_line
+        result
+      end
+    end
+
+    module Skipping # :nodoc: all
+      def failed(s)
+        super if !s or @options[:hide_skip]
+      end
+
+      private
+      def setup_options(opts, options)
+        super
+
+        opts.separator "skipping options:"
+
+        options[:hide_skip] = true
+
+        opts.on '-q', '--hide-skip', 'Hide skipped tests' do
+          options[:hide_skip] = true
+        end
+
+        opts.on '--show-skip', 'Show skipped tests' do
+          options[:hide_skip] = false
+        end
+      end
+
+      def _run_suites(suites, type)
+        result = super
+        report.reject!{|r| r.start_with? "Skipped:" } if @options[:hide_skip]
+        report.sort_by!{|r| r.start_with?("Skipped:") ? 0 : \
+                           (r.start_with?("Failure:") ? 1 : 2) }
+        failed(nil)
+        result
+      end
+    end
+
+    module Statistics
+      def update_list(list, rec, max)
+        if i = list.empty? ? 0 : list.bsearch_index {|*a| yield(*a)}
+          list[i, 0] = [rec]
+          list[max..-1] = [] if list.size >= max
+        end
+      end
+
+      def record(suite, method, assertions, time, error)
+        if @options.values_at(:longest, :most_asserted).any?
+          @tops ||= {}
+          rec = [suite.name, method, assertions, time, error]
+          if max = @options[:longest]
+            update_list(@tops[:longest] ||= [], rec, max) {|_,_,_,t,_|t<time}
+          end
+          if max = @options[:most_asserted]
+            update_list(@tops[:most_asserted] ||= [], rec, max) {|_,_,a,_,_|a<assertions}
+          end
+        end
+        # (((@record ||= {})[suite] ||= {})[method]) = [assertions, time, error]
+        super
+      end
+
+      def run(*args)
+        result = super
+        if @tops ||= nil
+          @tops.each do |t, list|
+            if list
+              puts "#{t.to_s.tr('_', ' ')} tests:"
+              list.each {|suite, method, assertions, time, error|
+                printf "%5.2fsec(%d): %s#%s\n", time, assertions, suite, method
+              }
+            end
+          end
+        end
+        result
+      end
+
+      private
+      def setup_options(opts, options)
+        super
+        opts.separator "statistics options:"
+        opts.on '--longest=N', Integer, 'Show longest N tests' do |n|
+          options[:longest] = n
+        end
+        opts.on '--most-asserted=N', Integer, 'Show most asserted N tests' do |n|
+          options[:most_asserted] = n
+        end
+      end
+    end
+
+    module StatusLine # :nodoc: all
+      def terminal_width
+        unless @terminal_width ||= nil
+          begin
+            require 'io/console'
+            width = $stdout.winsize[1]
+          rescue LoadError, NoMethodError, Errno::ENOTTY, Errno::EBADF, Errno::EINVAL
+            width = ENV["COLUMNS"].to_i.nonzero? || 80
+          end
+          width -= 1 if /mswin|mingw/ =~ RUBY_PLATFORM
+          @terminal_width = width
+        end
+        @terminal_width
+      end
+
+      def del_status_line(flush = true)
+        @status_line_size ||= 0
+        if @options[:job_status] == :replace
+          $stdout.print "\r"+" "*@status_line_size+"\r"
+        else
+          $stdout.puts if @status_line_size > 0
+        end
+        $stdout.flush if flush
+        @status_line_size = 0
+      end
+
+      def add_status(line)
+        @status_line_size ||= 0
+        if @options[:job_status] == :replace
+          line = line[0...(terminal_width-@status_line_size)]
+        end
+        print line
+        @status_line_size += line.size
+      end
+
+      def jobs_status(worker)
+        return if !@options[:job_status] or @options[:verbose]
+        if @options[:job_status] == :replace
+          status_line = @workers.map(&:to_s).join(" ")
+        else
+          status_line = worker.to_s
+        end
+        update_status(status_line) or (puts; nil)
+      end
+
+      def del_jobs_status
+        return unless @options[:job_status] == :replace && @status_line_size.nonzero?
+        del_status_line
+      end
+
+      def output
+        (@output ||= nil) || super
+      end
+
+      def _prepare_run(suites, type)
+        options[:job_status] ||= :replace if @tty && !@verbose
+        case options[:color]
+        when :always
+          color = true
+        when :auto, nil
+          color = true if @tty || @options[:job_status] == :replace
+        else
+          color = false
+        end
+        @colorize = Colorize.new(color, colors_file: File.join(__dir__, "../../colors"))
+        if color or @options[:job_status] == :replace
+          @verbose = !options[:parallel]
+        end
+        @output = Output.new(self) unless @options[:testing]
+        filter = options[:filter]
+        type = "#{type}_methods"
+        total = if filter
+                  suites.inject(0) {|n, suite| n + suite.send(type).grep(filter).size}
+                else
+                  suites.inject(0) {|n, suite| n + suite.send(type).size}
+                end
+        @test_count = 0
+        @total_tests = total.to_s(10)
+      end
+
+      def new_test(s)
+        @test_count += 1
+        update_status(s)
+      end
+
+      def update_status(s)
+        count = @test_count.to_s(10).rjust(@total_tests.size)
+        del_status_line(false)
+        add_status(@colorize.pass("[#{count}/#{@total_tests}]"))
+        add_status(" #{s}")
+        $stdout.print "\r" if @options[:job_status] == :replace and !@verbose
+        $stdout.flush
+      end
+
+      def _print(s); $stdout.print(s); end
+      def succeed; del_status_line; end
+
+      def failed(s)
+        return if s and @options[:job_status] != :replace
+        sep = "\n"
+        @report_count ||= 0
+        report.each do |msg|
+          if msg.start_with? "Skipped:"
+            if @options[:hide_skip]
+              del_status_line
+              next
+            end
+            color = :skip
+          else
+            color = :fail
+          end
+          first, msg = msg.split(/$/, 2)
+          first = sprintf("%3d) %s", @report_count += 1, first)
+          $stdout.print(sep, @colorize.decorate(first, color), msg, "\n")
+          sep = nil
+        end
+        report.clear
+      end
+
+      def initialize
+        super
+        @tty = $stdout.tty?
+      end
+
+      def run(*args)
+        result = super
+        puts "\nruby -v: #{RUBY_DESCRIPTION}"
+        result
+      end
+
+      private
+      def setup_options(opts, options)
+        super
+
+        opts.separator "status line options:"
+
+        options[:job_status] = nil
+
+        opts.on '--jobs-status [TYPE]', [:normal, :replace, :none],
+                "Show status of jobs every file; Disabled when --jobs isn't specified." do |type|
+          options[:job_status] = (type || :normal if type != :none)
+        end
+
+        opts.on '--color[=WHEN]',
+                [:always, :never, :auto],
+                "colorize the output.  WHEN defaults to 'always'", "or can be 'never' or 'auto'." do |c|
+          options[:color] = c || :always
+        end
+
+        opts.on '--tty[=WHEN]',
+                [:yes, :no],
+                "force to output tty control.  WHEN defaults to 'yes'", "or can be 'no'." do |c|
+          @tty = c != :no
+        end
+      end
+
+      class Output < Struct.new(:runner) # :nodoc: all
+        def puts(*a) $stdout.puts(*a) unless a.empty? end
+        def respond_to_missing?(*a) $stdout.respond_to?(*a) end
+        def method_missing(*a, &b) $stdout.__send__(*a, &b) end
+
+        def print(s)
+          case s
+          when /\A(.*\#.*) = \z/
+            runner.new_test($1)
+          when /\A(.* s) = \z/
+            runner.add_status(" = #$1")
+          when /\A\.+\z/
+            runner.succeed
+          when /\A[EFS]\z/
+            runner.failed(s)
+          else
+            $stdout.print(s)
+          end
+        end
+      end
+    end
+
+    module LoadPathOption # :nodoc: all
+      def non_options(files, options)
+        begin
+          require "rbconfig"
+        rescue LoadError
+          warn "#{caller(1, 1)[0]}: warning: Parallel running disabled because can't get path to ruby; run specify with --ruby argument"
+          options[:parallel] = nil
+        else
+          options[:ruby] ||= [RbConfig.ruby]
+        end
+
+        super
+      end
+
+      def setup_options(parser, options)
+        super
+        parser.separator "load path options:"
+        parser.on '-Idirectory', 'Add library load path' do |dirs|
+          dirs.split(':').each { |d| $LOAD_PATH.unshift d }
+        end
+      end
+    end
+
+    module GlobOption # :nodoc: all
+      @@testfile_prefix = "test"
+      @@testfile_suffix = "test"
+
+      def setup_options(parser, options)
+        super
+        parser.separator "globbing options:"
+        parser.on '-b', '--basedir=DIR', 'Base directory of test suites.' do |dir|
+          options[:base_directory] = dir
+        end
+        parser.on '-x', '--exclude REGEXP', 'Exclude test files on pattern.' do |pattern|
+          (options[:reject] ||= []) << pattern
+        end
+      end
+
+      def non_options(files, options)
+        paths = [options.delete(:base_directory), nil].uniq
+        if reject = options.delete(:reject)
+          reject_pat = Regexp.union(reject.map {|r| %r"#{r}"})
+        end
+        files.map! {|f|
+          f = f.tr(File::ALT_SEPARATOR, File::SEPARATOR) if File::ALT_SEPARATOR
+          ((paths if /\A\.\.?(?:\z|\/)/ !~ f) || [nil]).any? do |prefix|
+            if prefix
+              path = f.empty? ? prefix : "#{prefix}/#{f}"
+            else
+              next if f.empty?
+              path = f
+            end
+            if f.end_with?(File::SEPARATOR) or !f.include?(File::SEPARATOR) or File.directory?(path)
+              match = (Dir["#{path}/**/#{@@testfile_prefix}_*.rb"] + Dir["#{path}/**/*_#{@@testfile_suffix}.rb"]).uniq
+            else
+              match = Dir[path]
+            end
+            if !match.empty?
+              if reject
+                match.reject! {|n|
+                  n = n[(prefix.length+1)..-1] if prefix
+                  reject_pat =~ n
+                }
+              end
+              break match
+            elsif !reject or reject_pat !~ f and File.exist? path
+              break path
+            end
+          end or
+            raise ArgumentError, "file not found: #{f}"
+        }
+        files.flatten!
+        super(files, options)
+      end
+    end
+
+    module GCStressOption # :nodoc: all
+      def setup_options(parser, options)
+        super
+        parser.separator "GC options:"
+        parser.on '--[no-]gc-stress', 'Set GC.stress as true' do |flag|
+          options[:gc_stress] = flag
+        end
+      end
+
+      def non_options(files, options)
+        if options.delete(:gc_stress)
+          MiniTest::Unit::TestCase.class_eval do
+            oldrun = instance_method(:run)
+            define_method(:run) do |runner|
+              begin
+                gc_stress, GC.stress = GC.stress, true
+                oldrun.bind(self).call(runner)
+              ensure
+                GC.stress = gc_stress
+              end
+            end
+          end
+        end
+        super
+      end
+    end
+
+    module RequireFiles # :nodoc: all
+      def non_options(files, options)
+        return false if !super
+        errors = {}
+        result = false
+        files.each {|f|
+          d = File.dirname(path = File.realpath(f))
+          unless $:.include? d
+            $: << d
+          end
+          begin
+            require path unless options[:parallel]
+            result = true
+          rescue LoadError
+            next if errors[$!.message]
+            errors[$!.message] = true
+            puts "#{f}: #{$!}"
+          end
+        }
+        result
+      end
+    end
+
+    module RepeatOption # :nodoc: all
+      def setup_options(parser, options)
+        super
+        options[:repeat_count] = nil
+        parser.separator "repeat options:"
+        parser.on '--repeat-count=NUM', "Number of times to repeat", Integer do |n|
+          options[:repeat_count] = n
+        end
+      end
+
+      def _run_anything(type)
+        @repeat_count = @options[:repeat_count]
+        super
+      end
+    end
+
+    module ExcludesOption # :nodoc: all
+      class ExcludedMethods < Struct.new(:excludes)
+        def exclude(name, reason)
+          excludes[name] = reason
+        end
+
+        def exclude_from(klass)
+          excludes = self.excludes
+          pattern = excludes.keys.grep(Regexp).tap {|k|
+            break (Regexp.new(k.join('|')) unless k.empty?)
+          }
+          klass.class_eval do
+            public_instance_methods(false).each do |method|
+              if excludes[method] or (pattern and pattern =~ method)
+                remove_method(method)
+              end
+            end
+            public_instance_methods(true).each do |method|
+              if excludes[method] or (pattern and pattern =~ method)
+                undef_method(method)
+              end
+            end
+          end
+        end
+
+        def self.load(dirs, name)
+          return unless dirs and name
+          instance = nil
+          dirs.each do |dir|
+            path = File.join(dir, name.gsub(/::/, '/') + ".rb")
+            begin
+              src = File.read(path)
+            rescue Errno::ENOENT
+              nil
+            else
+              instance ||= new({})
+              instance.instance_eval(src, path)
+            end
+          end
+          instance
+        end
+      end
+
+      def setup_options(parser, options)
+        super
+        if excludes = ENV["EXCLUDES"]
+          excludes = excludes.split(File::PATH_SEPARATOR)
+        end
+        options[:excludes] = excludes || []
+        parser.separator "excludes options:"
+        parser.on '-X', '--excludes-dir DIRECTORY', "Directory name of exclude files" do |d|
+          options[:excludes].concat d.split(File::PATH_SEPARATOR)
+        end
+      end
+
+      def _run_suite(suite, type)
+        if ex = ExcludedMethods.load(@options[:excludes], suite.name)
+          ex.exclude_from(suite)
+        end
+        super
+      end
+    end
+
+    module TimeoutOption
+      def setup_options(parser, options)
+        super
+        parser.separator "timeout options:"
+        parser.on '--timeout-scale NUM', '--subprocess-timeout-scale NUM', "Scale timeout", Float do |scale|
+          raise OptionParser::InvalidArgument, "timeout scale must be positive" unless scale > 0
+          options[:timeout_scale] = scale
+        end
+      end
+
+      def non_options(files, options)
+        if scale = options[:timeout_scale] or
+          (scale = ENV["RUBY_TEST_TIMEOUT_SCALE"] || ENV["RUBY_TEST_SUBPROCESS_TIMEOUT_SCALE"] and
+           (scale = scale.to_f) > 0)
+          EnvUtil.timeout_scale = scale
+        end
+        super
+      end
+    end
+
+    class Runner < MiniTest::Unit # :nodoc: all
+      include Test::Unit::Options
+      include Test::Unit::StatusLine
+      include Test::Unit::Parallel
+      include Test::Unit::Statistics
+      include Test::Unit::Skipping
+      include Test::Unit::GlobOption
+      include Test::Unit::RepeatOption
+      include Test::Unit::LoadPathOption
+      include Test::Unit::GCStressOption
+      include Test::Unit::ExcludesOption
+      include Test::Unit::TimeoutOption
+      include Test::Unit::RunCount
+
+      class << self; undef autorun; end
+
+      @@stop_auto_run = false
+      def self.autorun
+        at_exit {
+          Test::Unit::RunCount.run_once {
+            exit(Test::Unit::Runner.new.run(ARGV) || true)
+          } unless @@stop_auto_run
+        } unless @@installed_at_exit
+        @@installed_at_exit = true
+      end
+
+      alias mini_run_suite _run_suite
+
+      # Overriding of MiniTest::Unit#puke
+      def puke klass, meth, e
+        # TODO:
+        #   this overriding is for minitest feature that skip messages are
+        #   hidden when not verbose (-v), note this is temporally.
+        n = report.size
+        rep = super
+        if MiniTest::Skip === e and /no message given\z/ =~ e.message
+          report.slice!(n..-1)
+          rep = "."
+        end
+        rep
+      end
+    end
+
+    class AutoRunner # :nodoc: all
+      class Runner < Test::Unit::Runner
+        include Test::Unit::RequireFiles
+      end
+
+      attr_accessor :to_run, :options
+
+      def initialize(force_standalone = false, default_dir = nil, argv = ARGV)
+        @force_standalone = force_standalone
+        @runner = Runner.new do |files, options|
+          options[:base_directory] ||= default_dir
+          files << default_dir if files.empty? and default_dir
+          @to_run = files
+          yield self if block_given?
+          files
+        end
+        Runner.runner = @runner
+        @options = @runner.option_parser
+        if @force_standalone
+          @options.banner.sub!(/\[options\]/, '\& tests...')
+        end
+        @argv = argv
+      end
+
+      def process_args(*args)
+        @runner.process_args(*args)
+        !@to_run.empty?
+      end
+
+      def run
+        if @force_standalone and not process_args(@argv)
+          abort @options.banner
+        end
+        @runner.run(@argv) || true
+      end
+
+      def self.run(*args)
+        new(*args).run
+      end
+    end
+
+    class ProxyError < StandardError # :nodoc: all
+      def initialize(ex)
+        @message = ex.message
+        @backtrace = ex.backtrace
+      end
+
+      attr_accessor :message, :backtrace
+    end
+  end
+end
+
+module MiniTest # :nodoc: all
+  class Unit
+  end
+end
+
+class MiniTest::Unit::TestCase # :nodoc: all
+  test_order = self.test_order
+  class << self
+    attr_writer :test_order
+    undef test_order
+  end
+  def self.test_order
+    defined?(@test_order) ? @test_order : superclass.test_order
+  end
+  self.test_order = test_order
+  undef run_test
+  RUN_TEST_TRACE = "#{__FILE__}:#{__LINE__+3}:in `run_test'".freeze
+  def run_test(name)
+    progname, $0 = $0, "#{$0}: #{self.class}##{name}"
+    self.__send__(name)
+  ensure
+    $@.delete(RUN_TEST_TRACE) if $@
+    $0 = progname
+  end
+end
+
+Test::Unit::Runner.autorun
diff --git a/tool/lib/test/unit/assertions.rb b/tool/lib/test/unit/assertions.rb
new file mode 100644
index 0000000000..169a3dcc7e
--- /dev/null
+++ b/tool/lib/test/unit/assertions.rb
@@ -0,0 +1,984 @@
+# frozen_string_literal: true
+require 'minitest/unit'
+require 'pp'
+
+module Test
+  module Unit
+    module Assertions
+      include MiniTest::Assertions
+
+      def mu_pp(obj) #:nodoc:
+        obj.pretty_inspect.chomp
+      end
+
+      MINI_DIR = File.join(File.dirname(File.dirname(File.expand_path(__FILE__))), "minitest") #:nodoc:
+
+      # :call-seq:
+      #   assert(test, [failure_message])
+      #
+      #Tests if +test+ is true.
+      #
+      #+msg+ may be a String or a Proc. If +msg+ is a String, it will be used
+      #as the failure message. Otherwise, the result of calling +msg+ will be
+      #used as the message if the assertion fails.
+      #
+      #If no +msg+ is given, a default message will be used.
+      #
+      #    assert(false, "This was expected to be true")
+      def assert(test, *msgs)
+        case msg = msgs.first
+        when String, Proc
+        when nil
+          msgs.shift
+        else
+          bt = caller.reject { |s| s.start_with?(MINI_DIR) }
+          raise ArgumentError, "assertion message must be String or Proc, but #{msg.class} was given.", bt
+        end unless msgs.empty?
+        super
+      end
+
+      # :call-seq:
+      #   assert_block( failure_message = nil )
+      #
+      #Tests the result of the given block. If the block does not return true,
+      #the assertion will fail. The optional +failure_message+ argument is the same as in
+      #Assertions#assert.
+      #
+      #    assert_block do
+      #      [1, 2, 3].any? { |num| num < 1 }
+      #    end
+      def assert_block(*msgs)
+        assert yield, *msgs
+      end
+
+      # :call-seq:
+      #   assert_raise( *args, &block )
+      #
+      #Tests if the given block raises an exception. Acceptable exception
+      #types may be given as optional arguments. If the last argument is a
+      #String, it will be used as the error message.
+      #
+      #    assert_raise do #Fails, no Exceptions are raised
+      #    end
+      #
+      #    assert_raise NameError do
+      #      puts x  #Raises NameError, so assertion succeeds
+      #    end
+      def assert_raise(*exp, &b)
+        case exp.last
+        when String, Proc
+          msg = exp.pop
+        end
+
+        begin
+          yield
+        rescue MiniTest::Skip => e
+          return e if exp.include? MiniTest::Skip
+          raise e
+        rescue Exception => e
+          expected = exp.any? { |ex|
+            if ex.instance_of? Module then
+              e.kind_of? ex
+            else
+              e.instance_of? ex
+            end
+          }
+
+          assert expected, proc {
+            exception_details(e, message(msg) {"#{mu_pp(exp)} exception expected, not"}.call)
+          }
+
+          return e
+        ensure
+          unless e
+            exp = exp.first if exp.size == 1
+
+            flunk(message(msg) {"#{mu_pp(exp)} expected but nothing was raised"})
+          end
+        end
+      end
+
+      def assert_raises(*exp, &b)
+        raise NoMethodError, "use assert_raise", caller
+      end
+
+      # :call-seq:
+      #   assert_raise_with_message(exception, expected, msg = nil, &block)
+      #
+      #Tests if the given block raises an exception with the expected
+      #message.
+      #
+      #    assert_raise_with_message(RuntimeError, "foo") do
+      #      nil #Fails, no Exceptions are raised
+      #    end
+      #
+      #    assert_raise_with_message(RuntimeError, "foo") do
+      #      raise ArgumentError, "foo" #Fails, different Exception is raised
+      #    end
+      #
+      #    assert_raise_with_message(RuntimeError, "foo") do
+      #      raise "bar" #Fails, RuntimeError is raised but the message differs
+      #    end
+      #
+      #    assert_raise_with_message(RuntimeError, "foo") do
+      #      raise "foo" #Raises RuntimeError with the message, so assertion succeeds
+      #    end
+      def assert_raise_with_message(exception, expected, msg = nil, &block)
+        case expected
+        when String
+          assert = :assert_equal
+        when Regexp
+          assert = :assert_match
+        else
+          raise TypeError, "Expected #{expected.inspect} to be a kind of String or Regexp, not #{expected.class}"
+        end
+
+        ex = m = nil
+        EnvUtil.with_default_internal(expected.encoding) do
+          ex = assert_raise(exception, msg || proc {"Exception(#{exception}) with message matches to #{expected.inspect}"}) do
+            yield
+          end
+          m = ex.message
+        end
+        msg = message(msg, "") {"Expected Exception(#{exception}) was raised, but the message doesn't match"}
+
+        if assert == :assert_equal
+          assert_equal(expected, m, msg)
+        else
+          msg = message(msg) { "Expected #{mu_pp expected} to match #{mu_pp m}" }
+          assert expected =~ m, msg
+          block.binding.eval("proc{|_|$~=_}").call($~)
+        end
+        ex
+      end
+
+      # :call-seq:
+      #   assert_nothing_raised( *args, &block )
+      #
+      #If any exceptions are given as arguments, the assertion will
+      #fail if one of those exceptions are raised. Otherwise, the test fails
+      #if any exceptions are raised.
+      #
+      #The final argument may be a failure message.
+      #
+      #    assert_nothing_raised RuntimeError do
+      #      raise Exception #Assertion passes, Exception is not a RuntimeError
+      #    end
+      #
+      #    assert_nothing_raised do
+      #      raise Exception #Assertion fails
+      #    end
+      def assert_nothing_raised(*args)
+        self._assertions += 1
+        if Module === args.last
+          msg = nil
+        else
+          msg = args.pop
+        end
+        begin
+          line = __LINE__; yield
+        rescue MiniTest::Skip
+          raise
+        rescue Exception => e
+          bt = e.backtrace
+          as = e.instance_of?(MiniTest::Assertion)
+          if as
+            ans = /\A#{Regexp.quote(__FILE__)}:#{line}:in /o
+            bt.reject! {|ln| ans =~ ln}
+          end
+          if ((args.empty? && !as) ||
+              args.any? {|a| a.instance_of?(Module) ? e.is_a?(a) : e.class == a })
+            msg = message(msg) { "Exception raised:\n<#{mu_pp(e)}>" }
+            raise MiniTest::Assertion, msg.call, bt
+          else
+            raise
+          end
+        end
+      end
+
+      # :call-seq:
+      #   assert_nothing_thrown( failure_message = nil, &block )
+      #
+      #Fails if the given block uses a call to Kernel#throw, and
+      #returns the result of the block otherwise.
+      #
+      #An optional failure message may be provided as the final argument.
+      #
+      #    assert_nothing_thrown "Something was thrown!" do
+      #      throw :problem?
+      #    end
+      def assert_nothing_thrown(msg=nil)
+        begin
+          ret = yield
+        rescue ArgumentError => error
+          raise error if /\Auncaught throw (.+)\z/m !~ error.message
+          msg = message(msg) { "<#{$1}> was thrown when nothing was expected" }
+          flunk(msg)
+        end
+        assert(true, "Expected nothing to be thrown")
+        ret
+      end
+
+      # :call-seq:
+      #   assert_throw( tag, failure_message = nil, &block )
+      #
+      #Fails unless the given block throws +tag+, returns the caught
+      #value otherwise.
+      #
+      #An optional failure message may be provided as the final argument.
+      #
+      #    tag = Object.new
+      #    assert_throw(tag, "#{tag} was not thrown!") do
+      #      throw tag
+      #    end
+      def assert_throw(tag, msg = nil)
+        ret = catch(tag) do
+          begin
+            yield(tag)
+          rescue UncaughtThrowError => e
+            thrown = e.tag
+          end
+          msg = message(msg) {
+            "Expected #{mu_pp(tag)} to have been thrown"\
+            "#{%Q[, not #{thrown}] if thrown}"
+          }
+          assert(false, msg)
+        end
+        assert(true)
+        ret
+      end
+
+      # :call-seq:
+      #   assert_equal( expected, actual, failure_message = nil )
+      #
+      #Tests if +expected+ is equal to +actual+.
+      #
+      #An optional failure message may be provided as the final argument.
+      def assert_equal(exp, act, msg = nil)
+        msg = message(msg) {
+          exp_str = mu_pp(exp)
+          act_str = mu_pp(act)
+          exp_comment = ''
+          act_comment = ''
+          if exp_str == act_str
+            if (exp.is_a?(String) && act.is_a?(String)) ||
+               (exp.is_a?(Regexp) && act.is_a?(Regexp))
+              exp_comment = " (#{exp.encoding})"
+              act_comment = " (#{act.encoding})"
+            elsif exp.is_a?(Float) && act.is_a?(Float)
+              exp_str = "%\#.#{Float::DIG+2}g" % exp
+              act_str = "%\#.#{Float::DIG+2}g" % act
+            elsif exp.is_a?(Time) && act.is_a?(Time)
+              if exp.subsec * 1000_000_000 == exp.nsec
+                exp_comment = " (#{exp.nsec}[ns])"
+              else
+                exp_comment = " (subsec=#{exp.subsec})"
+              end
+              if act.subsec * 1000_000_000 == act.nsec
+                act_comment = " (#{act.nsec}[ns])"
+              else
+                act_comment = " (subsec=#{act.subsec})"
+              end
+            elsif exp.class != act.class
+              # a subclass of Range, for example.
+              exp_comment = " (#{exp.class})"
+              act_comment = " (#{act.class})"
+            end
+          elsif !Encoding.compatible?(exp_str, act_str)
+            if exp.is_a?(String) && act.is_a?(String)
+              exp_str = exp.dump
+              act_str = act.dump
+              exp_comment = " (#{exp.encoding})"
+              act_comment = " (#{act.encoding})"
+            else
+              exp_str = exp_str.dump
+              act_str = act_str.dump
+            end
+          end
+          "<#{exp_str}>#{exp_comment} expected but was\n<#{act_str}>#{act_comment}"
+        }
+        assert(exp == act, msg)
+      end
+
+      # :call-seq:
+      #   assert_not_nil( expression, failure_message = nil )
+      #
+      #Tests if +expression+ is not nil.
+      #
+      #An optional failure message may be provided as the final argument.
+      def assert_not_nil(exp, msg=nil)
+        msg = message(msg) { "<#{mu_pp(exp)}> expected to not be nil" }
+        assert(!exp.nil?, msg)
+      end
+
+      # :call-seq:
+      #   assert_not_equal( expected, actual, failure_message = nil )
+      #
+      #Tests if +expected+ is not equal to +actual+.
+      #
+      #An optional failure message may be provided as the final argument.
+      def assert_not_equal(exp, act, msg=nil)
+        msg = message(msg) { "<#{mu_pp(exp)}> expected to be != to\n<#{mu_pp(act)}>" }
+        assert(exp != act, msg)
+      end
+
+      # :call-seq:
+      #   assert_no_match( regexp, string, failure_message = nil )
+      #
+      #Tests if the given Regexp does not match a given String.
+      #
+      #An optional failure message may be provided as the final argument.
+      def assert_no_match(regexp, string, msg=nil)
+        assert_instance_of(Regexp, regexp, "The first argument to assert_no_match should be a Regexp.")
+        self._assertions -= 1
+        msg = message(msg) { "<#{mu_pp(regexp)}> expected to not match\n<#{mu_pp(string)}>" }
+        assert(regexp !~ string, msg)
+      end
+
+      # :call-seq:
+      #   assert_not_same( expected, actual, failure_message = nil )
+      #
+      #Tests if +expected+ is not the same object as +actual+.
+      #This test uses Object#equal? to test equality.
+      #
+      #An optional failure message may be provided as the final argument.
+      #
+      #    assert_not_same("x", "x") #Succeeds
+      def assert_not_same(expected, actual, message="")
+        msg = message(msg) { build_message(message, <<EOT, expected, expected.__id__, actual, actual.__id__) }
+<?>
+with id <?> expected to not be equal\\? to
+<?>
+with id <?>.
+EOT
+        assert(!actual.equal?(expected), msg)
+      end
+
+      # :call-seq:
+      #   assert_respond_to( object, method, failure_message = nil )
+      #
+      #Tests if the given Object responds to +method+.
+      #
+      #An optional failure message may be provided as the final argument.
+      #
+      #    assert_respond_to("hello", :reverse)  #Succeeds
+      #    assert_respond_to("hello", :does_not_exist)  #Fails
+      def assert_respond_to(obj, (meth, *priv), msg = nil)
+        unless priv.empty?
+          msg = message(msg) {
+            "Expected #{mu_pp(obj)} (#{obj.class}) to respond to ##{meth}#{" privately" if priv[0]}"
+          }
+          return assert obj.respond_to?(meth, *priv), msg
+        end
+        #get rid of overcounting
+        if caller_locations(1, 1)[0].path.start_with?(MINI_DIR)
+          return if obj.respond_to?(meth)
+        end
+        super(obj, meth, msg)
+      end
+
+      # :call-seq:
+      #   assert_not_respond_to( object, method, failure_message = nil )
+      #
+      #Tests if the given Object does not respond to +method+.
+      #
+      #An optional failure message may be provided as the final argument.
+      #
+      #    assert_not_respond_to("hello", :reverse)  #Fails
+      #    assert_not_respond_to("hello", :does_not_exist)  #Succeeds
+      def assert_not_respond_to(obj, (meth, *priv), msg = nil)
+        unless priv.empty?
+          msg = message(msg) {
+            "Expected #{mu_pp(obj)} (#{obj.class}) to not respond to ##{meth}#{" privately" if priv[0]}"
+          }
+          return assert !obj.respond_to?(meth, *priv), msg
+        end
+        #get rid of overcounting
+        if caller_locations(1, 1)[0].path.start_with?(MINI_DIR)
+          return unless obj.respond_to?(meth)
+        end
+        refute_respond_to(obj, meth, msg)
+      end
+
+      # :call-seq:
+      #   assert_send( +send_array+, failure_message = nil )
+      #
+      # Passes if the method send returns a true value.
+      #
+      # +send_array+ is composed of:
+      # * A receiver
+      # * A method
+      # * Arguments to the method
+      #
+      # Example:
+      #   assert_send(["Hello world", :include?, "Hello"])    # -> pass
+      #   assert_send(["Hello world", :include?, "Goodbye"])  # -> fail
+      def assert_send send_ary, m = nil
+        recv, msg, *args = send_ary
+        m = message(m) {
+          if args.empty?
+            argsstr = ""
+          else
+            (argsstr = mu_pp(args)).sub!(/\A\[(.*)\]\z/m, '(\1)')
+          end
+          "Expected #{mu_pp(recv)}.#{msg}#{argsstr} to return true"
+        }
+        assert recv.__send__(msg, *args), m
+      end
+
+      # :call-seq:
+      #   assert_not_send( +send_array+, failure_message = nil )
+      #
+      # Passes if the method send doesn't return a true value.
+      #
+      # +send_array+ is composed of:
+      # * A receiver
+      # * A method
+      # * Arguments to the method
+      #
+      # Example:
+      #   assert_not_send([[1, 2], :member?, 1]) # -> fail
+      #   assert_not_send([[1, 2], :member?, 4]) # -> pass
+      def assert_not_send send_ary, m = nil
+        recv, msg, *args = send_ary
+        m = message(m) {
+          if args.empty?
+            argsstr = ""
+          else
+            (argsstr = mu_pp(args)).sub!(/\A\[(.*)\]\z/m, '(\1)')
+          end
+          "Expected #{mu_pp(recv)}.#{msg}#{argsstr} to return false"
+        }
+        assert !recv.__send__(msg, *args), m
+      end
+
+      ms = instance_methods(true).map {|sym| sym.to_s }
+      ms.grep(/\Arefute_/) do |m|
+        mname = ('assert_not_'.dup << m.to_s[/.*?_(.*)/, 1])
+        alias_method(mname, m) unless ms.include? mname
+      end
+      alias assert_include assert_includes
+      alias assert_not_include assert_not_includes
+
+      def assert_all?(obj, m = nil, &blk)
+        failed = []
+        obj.each do |*a, &b|
+          unless blk.call(*a, &b)
+            failed << (a.size > 1 ? a : a[0])
+          end
+        end
+        assert(failed.empty?, message(m) {failed.pretty_inspect})
+      end
+
+      def assert_not_all?(obj, m = nil, &blk)
+        failed = []
+        obj.each do |*a, &b|
+          if blk.call(*a, &b)
+            failed << (a.size > 1 ? a : a[0])
+          end
+        end
+        assert(failed.empty?, message(m) {failed.pretty_inspect})
+      end
+
+      # compatibility with test-unit
+      alias pend skip
+
+      if defined?(RubyVM::InstructionSequence)
+        def syntax_check(code, fname, line)
+          code = code.dup.force_encoding(Encoding::UTF_8)
+          RubyVM::InstructionSequence.compile(code, fname, fname, line)
+          :ok
+        end
+      else
+        def syntax_check(code, fname, line)
+          code = code.b
+          code.sub!(/\A(?:\xef\xbb\xbf)?(\s*\#.*$)*(\n)?/n) {
+            "#$&#{"\n" if $1 && !$2}BEGIN{throw tag, :ok}\n"
+          }
+          code = code.force_encoding(Encoding::UTF_8)
+          catch {|tag| eval(code, binding, fname, line - 1)}
+        end
+      end
+
+      def prepare_syntax_check(code, fname = nil, mesg = nil, verbose: nil)
+        fname ||= caller_locations(2, 1)[0]
+        mesg ||= fname.to_s
+        verbose, $VERBOSE = $VERBOSE, verbose
+        case
+        when Array === fname
+          fname, line = *fname
+        when defined?(fname.path) && defined?(fname.lineno)
+          fname, line = fname.path, fname.lineno
+        else
+          line = 1
+        end
+        yield(code, fname, line, message(mesg) {
+                if code.end_with?("\n")
+                  "```\n#{code}```\n"
+                else
+                  "```\n#{code}\n```\n""no-newline"
+                end
+              })
+      ensure
+        $VERBOSE = verbose
+      end
+
+      def assert_valid_syntax(code, *args, **opt)
+        prepare_syntax_check(code, *args, **opt) do |src, fname, line, mesg|
+          yield if defined?(yield)
+          assert_nothing_raised(SyntaxError, mesg) do
+            assert_equal(:ok, syntax_check(src, fname, line), mesg)
+          end
+        end
+      end
+
+      def assert_syntax_error(code, error, *args)
+        prepare_syntax_check(code, *args) do |src, fname, line, mesg|
+          yield if defined?(yield)
+          e = assert_raise(SyntaxError, mesg) do
+            syntax_check(src, fname, line)
+          end
+          assert_match(error, e.message, mesg)
+          e
+        end
+      end
+
+      def assert_normal_exit(testsrc, message = '', child_env: nil, **opt)
+        assert_valid_syntax(testsrc, caller_locations(1, 1)[0])
+        if child_env
+          child_env = [child_env]
+        else
+          child_env = []
+        end
+        out, _, status = EnvUtil.invoke_ruby(child_env + %W'-W0', testsrc, true, :merge_to_stdout, **opt)
+        assert !status.signaled?, FailDesc[status, message, out]
+      end
+
+      FailDesc = proc do |status, message = "", out = ""|
+        pid = status.pid
+        now = Time.now
+        faildesc = proc do
+          if signo = status.termsig
+            signame = Signal.signame(signo)
+            sigdesc = "signal #{signo}"
+          end
+          log = EnvUtil.diagnostic_reports(signame, pid, now)
+          if signame
+            sigdesc = "SIG#{signame} (#{sigdesc})"
+          end
+          if status.coredump?
+            sigdesc = "#{sigdesc} (core dumped)"
+          end
+          full_message = ''.dup
+          message = message.call if Proc === message
+          if message and !message.empty?
+            full_message << message << "\n"
+          end
+          full_message << "pid #{pid}"
+          full_message << " exit #{status.exitstatus}" if status.exited?
+          full_message << " killed by #{sigdesc}" if sigdesc
+          if out and !out.empty?
+            full_message << "\n" << out.b.gsub(/^/, '| ')
+            full_message.sub!(/(?<!\n)\z/, "\n")
+          end
+          if log
+            full_message << "Diagnostic reports:\n" << log.b.gsub(/^/, '| ')
+          end
+          full_message
+        end
+        faildesc
+      end
+
+      def assert_in_out_err(args, test_stdin = "", test_stdout = [], test_stderr = [], message = nil,
+                            success: nil, **opt)
+        args = Array(args).dup
+        args.insert((Hash === args[0] ? 1 : 0), '--disable=gems')
+        stdout, stderr, status = EnvUtil.invoke_ruby(args, test_stdin, true, true, **opt)
+        if signo = status.termsig
+          EnvUtil.diagnostic_reports(Signal.signame(signo), status.pid, Time.now)
+        end
+        if block_given?
+          raise "test_stdout ignored, use block only or without block" if test_stdout != []
+          raise "test_stderr ignored, use block only or without block" if test_stderr != []
+          yield(stdout.lines.map {|l| l.chomp }, stderr.lines.map {|l| l.chomp }, status)
+        else
+          all_assertions(message) do |a|
+            [["stdout", test_stdout, stdout], ["stderr", test_stderr, stderr]].each do |key, exp, act|
+              a.for(key) do
+                if exp.is_a?(Regexp)
+                  assert_match(exp, act)
+                elsif exp.all? {|e| String === e}
+                  assert_equal(exp, act.lines.map {|l| l.chomp })
+                else
+                  assert_pattern_list(exp, act)
+                end
+              end
+            end
+            unless success.nil?
+              a.for("success?") do
+                if success
+                  assert_predicate(status, :success?)
+                else
+                  assert_not_predicate(status, :success?)
+                end
+              end
+            end
+          end
+          status
+        end
+      end
+
+      def assert_ruby_status(args, test_stdin="", message=nil, **opt)
+        out, _, status = EnvUtil.invoke_ruby(args, test_stdin, true, :merge_to_stdout, **opt)
+        desc = FailDesc[status, message, out]
+        assert(!status.signaled?, desc)
+        message ||= "ruby exit status is not success:"
+        assert(status.success?, desc)
+      end
+
+      ABORT_SIGNALS = Signal.list.values_at(*%w"ILL ABRT BUS SEGV TERM")
+
+      def assert_separately(args, file = nil, line = nil, src, ignore_stderr: nil, **opt)
+        unless file and line
+          loc, = caller_locations(1,1)
+          file ||= loc.path
+          line ||= loc.lineno
+        end
+        src = <<eom
+# -*- coding: #{line += __LINE__; src.encoding}; -*-
+  require #{__dir__.dump};include Test::Unit::Assertions
+  END {
+    puts [Marshal.dump($!)].pack('m'), "assertions=\#{self._assertions}"
+  }
+#{line -= __LINE__; src}
+  class Test::Unit::Runner
+    @@stop_auto_run = true
+  end
+eom
+        args = args.dup
+        args.insert((Hash === args.first ? 1 : 0), "-w", "--disable=gems", *$:.map {|l| "-I#{l}"})
+        stdout, stderr, status = EnvUtil.invoke_ruby(args, src, true, true, **opt)
+        abort = status.coredump? || (status.signaled? && ABORT_SIGNALS.include?(status.termsig))
+        assert(!abort, FailDesc[status, nil, stderr])
+        self._assertions += stdout[/^assertions=(\d+)/, 1].to_i
+        begin
+          res = Marshal.load(stdout.unpack("m")[0])
+        rescue => marshal_error
+          ignore_stderr = nil
+        end
+        if res
+          if bt = res.backtrace
+            bt.each do |l|
+              l.sub!(/\A-:(\d+)/){"#{file}:#{line + $1.to_i}"}
+            end
+            bt.concat(caller)
+          else
+            res.set_backtrace(caller)
+          end
+          raise res unless SystemExit === res
+        end
+
+        # really is it succeed?
+        unless ignore_stderr
+          # the body of assert_separately must not output anything to detect error
+          assert(stderr.empty?, FailDesc[status, "assert_separately failed with error message", stderr])
+        end
+        assert(status.success?, FailDesc[status, "assert_separately failed", stderr])
+        raise marshal_error if marshal_error
+      end
+
+      def assert_warning(pat, msg = nil)
+        result = nil
+        stderr = EnvUtil.with_default_internal(pat.encoding) {
+          EnvUtil.verbose_warning {
+            result = yield
+          }
+        }
+        msg = message(msg) {diff pat, stderr}
+        assert(pat === stderr, msg)
+        result
+      end
+
+      def assert_warn(*args)
+        assert_warning(*args) {$VERBOSE = false; yield}
+      end
+
+      def assert_no_warning(pat, msg = nil)
+        result = nil
+        stderr = EnvUtil.verbose_warning {
+          EnvUtil.with_default_internal(pat.encoding) {
+            result = yield
+          }
+        }
+        msg = message(msg) {diff pat, stderr}
+        refute(pat === stderr, msg)
+        result
+      end
+
+      def assert_no_memory_leak(args, prepare, code, message=nil, limit: 2.0, rss: false, **opt)
+        # TODO: consider choosing some appropriate limit for MJIT and stop skipping this once it does not randomly fail
+        skip 'assert_no_memory_leak may consider MJIT memory usage as leak' if defined?(RubyVM::MJIT) && RubyVM::MJIT.enabled?
+
+        require_relative '../../memory_status'
+        raise MiniTest::Skip, "unsupported platform" unless defined?(Memory::Status)
+
+        token = "\e[7;1m#{$$.to_s}:#{Time.now.strftime('%s.%L')}:#{rand(0x10000).to_s(16)}:\e[m"
+        token_dump = token.dump
+        token_re = Regexp.quote(token)
+        envs = args.shift if Array === args and Hash === args.first
+        args = [
+          "--disable=gems",
+          "-r", File.expand_path("../../../memory_status", __FILE__),
+          *args,
+          "-v", "-",
+        ]
+        if defined? Memory::NO_MEMORY_LEAK_ENVS then
+          envs ||= {}
+          newenvs = envs.merge(Memory::NO_MEMORY_LEAK_ENVS) { |_, _, _| break }
+          envs = newenvs if newenvs
+        end
+        args.unshift(envs) if envs
+        cmd = [
+          'END {STDERR.puts '"#{token_dump}"'"FINAL=#{Memory::Status.new}"}',
+          prepare,
+          'STDERR.puts('"#{token_dump}"'"START=#{$initial_status = Memory::Status.new}")',
+          '$initial_size = $initial_status.size',
+          code,
+          'GC.start',
+        ].join("\n")
+        _, err, status = EnvUtil.invoke_ruby(args, cmd, true, true, **opt)
+        before = err.sub!(/^#{token_re}START=(\{.*\})\n/, '') && Memory::Status.parse($1)
+        after = err.sub!(/^#{token_re}FINAL=(\{.*\})\n/, '') && Memory::Status.parse($1)
+        assert(status.success?, FailDesc[status, message, err])
+        ([:size, (rss && :rss)] & after.members).each do |n|
+          b = before[n]
+          a = after[n]
+          next unless a > 0 and b > 0
+          assert_operator(a.fdiv(b), :<, limit, message(message) {"#{n}: #{b} => #{a}"})
+        end
+      rescue LoadError
+        skip
+      end
+
+      # kernel resolution can limit the minimum time we can measure
+      # [ruby-core:81540]
+      MIN_HZ = MiniTest::Unit::TestCase.windows? ? 67 : 100
+      MIN_MEASURABLE = 1.0 / MIN_HZ
+
+      def assert_cpu_usage_low(msg = nil, pct: 0.05, wait: 1.0, stop: nil)
+        require 'benchmark'
+
+        wait = EnvUtil.apply_timeout_scale(wait)
+        if wait < 0.1 # TIME_QUANTUM_USEC in thread_pthread.c
+          warn "test #{msg || 'assert_cpu_usage_low'} too short to be accurate"
+        end
+        tms = Benchmark.measure(msg || '') do
+          if stop
+            th = Thread.start {sleep wait; stop.call}
+            yield
+            th.join
+          else
+            begin
+              Timeout.timeout(wait) {yield}
+            rescue Timeout::Error
+            end
+          end
+        end
+
+        max = pct * tms.real
+        min_measurable = MIN_MEASURABLE
+        min_measurable *= 1.30 # add a little (30%) to account for misc. overheads
+        if max < min_measurable
+          max = min_measurable
+        end
+
+        assert_operator tms.total, :<=, max, msg
+      end
+
+      def assert_is_minus_zero(f)
+        assert(1.0/f == -Float::INFINITY, "#{f} is not -0.0")
+      end
+
+      def assert_file
+        AssertFile
+      end
+
+      # pattern_list is an array which contains regexp and :*.
+      # :* means any sequence.
+      #
+      # pattern_list is anchored.
+      # Use [:*, regexp, :*] for non-anchored match.
+      def assert_pattern_list(pattern_list, actual, message=nil)
+        rest = actual
+        anchored = true
+        pattern_list.each_with_index {|pattern, i|
+          if pattern == :*
+            anchored = false
+          else
+            if anchored
+              match = /\A#{pattern}/.match(rest)
+            else
+              match = pattern.match(rest)
+            end
+            unless match
+              msg = message(msg) {
+                expect_msg = "Expected #{mu_pp pattern}\n"
+                if /\n[^\n]/ =~ rest
+                  actual_mesg = +"to match\n"
+                  rest.scan(/.*\n+/) {
+                    actual_mesg << '  ' << $&.inspect << "+\n"
+                  }
+                  actual_mesg.sub!(/\+\n\z/, '')
+                else
+                  actual_mesg = "to match " + mu_pp(rest)
+                end
+                actual_mesg << "\nafter #{i} patterns with #{actual.length - rest.length} characters"
+                expect_msg + actual_mesg
+              }
+              assert false, msg
+            end
+            rest = match.post_match
+            anchored = true
+          end
+        }
+        if anchored
+          assert_equal("", rest)
+        end
+      end
+
+      # threads should respond to shift method.
+      # Array can be used.
+      def assert_join_threads(threads, message = nil)
+        errs = []
+        values = []
+        while th = threads.shift
+          begin
+            values << th.value
+          rescue Exception
+            errs << [th, $!]
+            th = nil
+          end
+        end
+        values
+      ensure
+        if th&.alive?
+          th.raise(Timeout::Error.new)
+          th.join rescue errs << [th, $!]
+        end
+        if !errs.empty?
+          msg = "exceptions on #{errs.length} threads:\n" +
+            errs.map {|t, err|
+            "#{t.inspect}:\n" +
+              err.full_message(highlight: false, order: :top)
+          }.join("\n---\n")
+          if message
+            msg = "#{message}\n#{msg}"
+          end
+          raise MiniTest::Assertion, msg
+        end
+      end
+
+      class << (AssertFile = Struct.new(:failure_message).new)
+        include Assertions
+        def assert_file_predicate(predicate, *args)
+          if /\Anot_/ =~ predicate
+            predicate = $'
+            neg = " not"
+          end
+          result = File.__send__(predicate, *args)
+          result = !result if neg
+          mesg = "Expected file ".dup << args.shift.inspect
+          mesg << "#{neg} to be #{predicate}"
+          mesg << mu_pp(args).sub(/\A\[(.*)\]\z/m, '(\1)') unless args.empty?
+          mesg << " #{failure_message}" if failure_message
+          assert(result, mesg)
+        end
+        alias method_missing assert_file_predicate
+
+        def for(message)
+          clone.tap {|a| a.failure_message = message}
+        end
+      end
+
+      class AllFailures
+        attr_reader :failures
+
+        def initialize
+          @count = 0
+          @failures = {}
+        end
+
+        def for(key)
+          @count += 1
+          yield
+        rescue Exception => e
+          @failures[key] = [@count, e]
+        end
+
+        def foreach(*keys)
+          keys.each do |key|
+            @count += 1
+            begin
+              yield key
+            rescue Exception => e
+              @failures[key] = [@count, e]
+            end
+          end
+        end
+
+        def message
+          i = 0
+          total = @count.to_s
+          fmt = "%#{total.size}d"
+          @failures.map {|k, (n, v)|
+            v = v.message
+            "\n#{i+=1}. [#{fmt%n}/#{total}] Assertion for #{k.inspect}\n#{v.b.gsub(/^/, '   | ').force_encoding(v.encoding)}"
+          }.join("\n")
+        end
+
+        def pass?
+          @failures.empty?
+        end
+      end
+
+      def assert_all_assertions(msg = nil)
+        all = AllFailures.new
+        yield all
+      ensure
+        assert(all.pass?, message(msg) {all.message.chomp(".")})
+      end
+      alias all_assertions assert_all_assertions
+
+      def assert_all_assertions_foreach(msg = nil, *keys, &block)
+        all = AllFailures.new
+        all.foreach(*keys, &block)
+      ensure
+        assert(all.pass?, message(msg) {all.message.chomp(".")})
+      end
+      alias all_assertions_foreach assert_all_assertions_foreach
+
+      def build_message(head, template=nil, *arguments) #:nodoc:
+        template &&= template.chomp
+        template.gsub(/\G((?:[^\\]|\\.)*?)(\\)?\?/) { $1 + ($2 ? "?" : mu_pp(arguments.shift)) }
+      end
+
+      def message(msg = nil, *args, &default) # :nodoc:
+        if Proc === msg
+          super(nil, *args) do
+            ary = [msg.call, (default.call if default)].compact.reject(&:empty?)
+            if 1 < ary.length
+              ary[0...-1] = ary[0...-1].map {|str| str.sub(/(?<!\.)\z/, '.') }
+            end
+            begin
+              ary.join("\n")
+            rescue Encoding::CompatibilityError
+              ary.map(&:b).join("\n")
+            end
+          end
+        else
+          super
+        end
+      end
+    end
+  end
+end
diff --git a/tool/lib/test/unit/parallel.rb b/tool/lib/test/unit/parallel.rb
new file mode 100644
index 0000000000..d851326aca
--- /dev/null
+++ b/tool/lib/test/unit/parallel.rb
@@ -0,0 +1,208 @@
+# frozen_string_literal: true
+$LOAD_PATH.unshift "#{File.dirname(__FILE__)}/../.."
+require 'test/unit'
+
+module Test
+  module Unit
+    class Worker < Runner # :nodoc:
+      class << self
+        undef autorun
+      end
+
+      alias orig_run_suite mini_run_suite
+      undef _run_suite
+      undef _run_suites
+      undef run
+
+      def increment_io(orig) # :nodoc:
+        *rest, io = 32.times.inject([orig.dup]){|ios, | ios << ios.last.dup }
+        rest.each(&:close)
+        io
+      end
+
+      def _run_suites(suites, type) # :nodoc:
+        suites.map do |suite|
+          _run_suite(suite, type)
+        end
+      end
+
+      def _run_suite(suite, type) # :nodoc:
+        @partial_report = []
+        orig_testout = MiniTest::Unit.output
+        i,o = IO.pipe
+
+        MiniTest::Unit.output = o
+        orig_stdin, orig_stdout = $stdin, $stdout
+
+        th = Thread.new do
+          begin
+            while buf = (self.verbose ? i.gets : i.readpartial(1024))
+              _report "p", buf
+            end
+          rescue IOError
+          rescue Errno::EPIPE
+          end
+        end
+
+        e, f, s = @errors, @failures, @skips
+
+        begin
+          result = orig_run_suite(suite, type)
+        rescue Interrupt
+          @need_exit = true
+          result = [nil,nil]
+        end
+
+        MiniTest::Unit.output = orig_testout
+        $stdin = orig_stdin
+        $stdout = orig_stdout
+
+        o.close
+        begin
+          th.join
+        rescue IOError
+          raise unless /stream closed|closed stream/ =~ $!.message
+        end
+        i.close
+
+        result << @partial_report
+        @partial_report = nil
+        result << [@errors-e,@failures-f,@skips-s]
+        result << ($: - @old_loadpath)
+        result << suite.name
+
+        begin
+          _report "done", Marshal.dump(result)
+        rescue Errno::EPIPE; end
+        return result
+      ensure
+        MiniTest::Unit.output = orig_stdout
+        $stdin = orig_stdin if orig_stdin
+        $stdout = orig_stdout if orig_stdout
+        o.close if o && !o.closed?
+        i.close if i && !i.closed?
+      end
+
+      def run(args = []) # :nodoc:
+        process_args args
+        @@stop_auto_run = true
+        @opts = @options.dup
+        @need_exit = false
+
+        @old_loadpath = []
+        begin
+          begin
+            @stdout = increment_io(STDOUT)
+            @stdin = increment_io(STDIN)
+          rescue
+            exit 2
+          end
+          exit 2 unless @stdout && @stdin
+
+          @stdout.sync = true
+          _report "ready!"
+          while buf = @stdin.gets
+            case buf.chomp
+            when /^loadpath (.+?)$/
+              @old_loadpath = $:.dup
+              $:.push(*Marshal.load($1.unpack("m")[0].force_encoding("ASCII-8BIT"))).uniq!
+            when /^run (.+?) (.+?)$/
+              _report "okay"
+
+              @options = @opts.dup
+              suites = MiniTest::Unit::TestCase.test_suites
+
+              begin
+                require File.realpath($1)
+              rescue LoadError
+                _report "after", Marshal.dump([$1, ProxyError.new($!)])
+                _report "ready"
+                next
+              end
+              _run_suites MiniTest::Unit::TestCase.test_suites-suites, $2.to_sym
+
+              if @need_exit
+                begin
+                  _report "bye"
+                rescue Errno::EPIPE; end
+                exit
+              else
+                _report "ready"
+              end
+            when /^quit$/
+              begin
+                _report "bye"
+              rescue Errno::EPIPE; end
+              exit
+            end
+          end
+        rescue Errno::EPIPE
+        rescue Exception => e
+          begin
+            trace = e.backtrace || ['unknown method']
+            err = ["#{trace.shift}: #{e.message} (#{e.class})"] + trace.map{|t| t.prepend("\t") }
+
+            _report "bye", Marshal.dump(err.join("\n"))
+          rescue Errno::EPIPE;end
+          exit
+        ensure
+          @stdin.close if @stdin
+          @stdout.close if @stdout
+        end
+      end
+
+      def _report(res, *args) # :nodoc:
+        @stdout.write(args.empty? ? "#{res}\n" : "#{res} #{args.pack("m0")}\n")
+      end
+
+      def puke(klass, meth, e) # :nodoc:
+        if e.is_a?(MiniTest::Skip)
+          new_e = MiniTest::Skip.new(e.message)
+          new_e.set_backtrace(e.backtrace)
+          e = new_e
+        end
+        @partial_report << [klass.name, meth, e.is_a?(MiniTest::Assertion) ? e : ProxyError.new(e)]
+        super
+      end
+
+      def record(suite, method, assertions, time, error) # :nodoc:
+        case error
+        when nil
+        when MiniTest::Assertion, MiniTest::Skip
+          case error.cause
+          when nil, MiniTest::Assertion, MiniTest::Skip
+          else
+            bt = error.backtrace
+            error = error.class.new(error.message)
+            error.set_backtrace(bt)
+          end
+        else
+          error = ProxyError.new(error)
+        end
+        _report "record", Marshal.dump([suite.name, method, assertions, time, error])
+        super
+      end
+    end
+  end
+end
+
+if $0 == __FILE__
+  module Test
+    module Unit
+      class TestCase < MiniTest::Unit::TestCase # :nodoc: all
+        undef on_parallel_worker?
+        def on_parallel_worker?
+          true
+        end
+      end
+    end
+  end
+  require 'rubygems'
+  module Gem # :nodoc:
+  end
+  class Gem::TestCase < MiniTest::Unit::TestCase # :nodoc:
+    @@project_dir = File.expand_path('../../../../..', __FILE__)
+  end
+
+  Test::Unit::Worker.new.run(ARGV)
+end
diff --git a/tool/lib/test/unit/testcase.rb b/tool/lib/test/unit/testcase.rb
new file mode 100644
index 0000000000..58cfbcab99
--- /dev/null
+++ b/tool/lib/test/unit/testcase.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+require 'test/unit/assertions'
+
+module Test
+  module Unit
+    # remove silly TestCase class
+    remove_const(:TestCase) if defined?(self::TestCase)
+
+    class TestCase < MiniTest::Unit::TestCase # :nodoc: all
+      include Assertions
+
+      def on_parallel_worker?
+        false
+      end
+
+      def run runner
+        @options = runner.options
+        super runner
+      end
+
+      def self.test_order
+        :sorted
+      end
+
+      def self.method_added(name)
+        super
+        return unless name.to_s.start_with?("test_")
+        @test_methods ||= {}
+        if @test_methods[name]
+          warn "test/unit warning: method #{ self }##{ name } is redefined"
+        end
+        @test_methods[name] = true
+      end
+    end
+  end
+end
diff --git a/tool/lib/tracepointchecker.rb b/tool/lib/tracepointchecker.rb
new file mode 100644
index 0000000000..47822ecef5
--- /dev/null
+++ b/tool/lib/tracepointchecker.rb
@@ -0,0 +1,126 @@
+# frozen_string_literal: true
+module TracePointChecker
+  STATE = {
+    count: 0,
+    running: false,
+  }
+
+  module ZombieTraceHunter
+    def tracepoint_capture_stat_get
+      TracePoint.stat.map{|k, (activated, deleted)|
+        deleted = 0 unless @tracepoint_captured_singlethread
+        [k, activated, deleted]
+      }
+    end
+
+    def before_setup
+      @tracepoint_captured_singlethread = (Thread.list.size == 1)
+      @tracepoint_captured_stat = tracepoint_capture_stat_get()
+      super
+    end
+
+    def after_teardown
+      super
+
+      # detect zombie traces.
+      assert_equal(
+        @tracepoint_captured_stat,
+        tracepoint_capture_stat_get(),
+        "The number of active/deleted trace events was changed"
+      )
+      # puts "TracePoint - deleted: #{deleted}" if deleted > 0
+
+      TracePointChecker.check if STATE[:running]
+    end
+  end
+
+  MAIN_THREAD = Thread.current
+  TRACES = []
+
+  def self.prefix event
+    case event
+    when :call, :return
+      :n
+    when :c_call, :c_return
+      :c
+    when :b_call, :b_return
+      :b
+    end
+  end
+
+  def self.clear_call_stack
+    Thread.current[:call_stack] = []
+  end
+
+  def self.call_stack
+    stack = Thread.current[:call_stack]
+    stack = clear_call_stack unless stack
+    stack
+  end
+
+  def self.verbose_out label, method
+    puts label => call_stack, :count => STATE[:count], :method => method
+  end
+
+  def self.method_label tp
+    "#{prefix(tp.event)}##{tp.method_id}"
+  end
+
+  def self.start verbose: false, stop_at_failure: false
+    call_events = %i(a_call)
+    return_events = %i(a_return)
+    clear_call_stack
+
+    STATE[:running] = true
+
+    TRACES << TracePoint.new(*call_events){|tp|
+      next if Thread.current != MAIN_THREAD
+
+      method = method_label(tp)
+      call_stack.push method
+      STATE[:count] += 1
+
+      verbose_out :psuh, method if verbose
+    }
+
+    TRACES << TracePoint.new(*return_events){|tp|
+      next if Thread.current != MAIN_THREAD
+      STATE[:count] += 1
+
+      method = "#{prefix(tp.event)}##{tp.method_id}"
+      verbose_out :pop1, method if verbose
+
+      stored_method = call_stack.pop
+      next if stored_method.nil?
+
+      verbose_out :pop2, method if verbose
+
+      if stored_method != method
+        stop if stop_at_failure
+        RubyVM::SDR() if defined? RubyVM::SDR()
+        call_stack.clear
+        raise "#{stored_method} is expected, but #{method} (count: #{STATE[:count]})"
+      end
+    }
+
+    TRACES.each{|trace| trace.enable}
+  end
+
+  def self.stop
+    STATE[:running] = true
+    TRACES.each{|trace| trace.disable}
+    TRACES.clear
+  end
+
+  def self.check
+    TRACES.each{|trace|
+      raise "trace #{trace} should not be deactivated" unless trace.enabled?
+    }
+  end
+end if defined?(TracePoint.stat)
+
+class ::Test::Unit::TestCase
+  include TracePointChecker::ZombieTraceHunter
+end if defined?(TracePointChecker)
+
+# TracePointChecker.start verbose: false
diff --git a/tool/lib/with_different_ofs.rb b/tool/lib/with_different_ofs.rb
new file mode 100644
index 0000000000..559ed6a1d1
--- /dev/null
+++ b/tool/lib/with_different_ofs.rb
@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+module DifferentOFS
+  module WithDifferentOFS
+    def setup
+      super
+      verbose, $VERBOSE = $VERBOSE, nil
+      @ofs, $, = $,, "-"
+      $VERBOSE = verbose
+    end
+    def teardown
+      verbose, $VERBOSE = $VERBOSE, nil
+      $, = @ofs
+      $VERBOSE = verbose
+      super
+    end
+  end
+
+  def self.extended(klass)
+    super(klass)
+    klass.const_set(:DifferentOFS, Class.new(klass).class_eval {include WithDifferentOFS}).name
+  end
+end
diff --git a/tool/lib/zombie_hunter.rb b/tool/lib/zombie_hunter.rb
new file mode 100644
index 0000000000..33bc467941
--- /dev/null
+++ b/tool/lib/zombie_hunter.rb
@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+module ZombieHunter
+  def after_teardown
+    super
+    assert_empty(Process.waitall)
+  end
+end
+
+Test::Unit::TestCase.include ZombieHunter