Split test files for test-framework that are test-unit and minitest to tool direcotry.

17 files changed, 2800 insertions, 0 deletions

diff --git a/tool/test/minitest/metametameta.rb b/tool/test/minitest/metametameta.rb
new file mode 100644
index 0000000000..a12717c8b1
--- /dev/null
+++ b/tool/test/minitest/metametameta.rb
@@ -0,0 +1,71 @@
+# encoding: utf-8
+# frozen_string_literal: false
+
+require 'tempfile'
+require 'stringio'
+require 'minitest/autorun'
+
+class MiniTest::Unit::TestCase
+  def clean s
+    s.gsub(/^ {6}/, '')
+  end
+end
+
+class MetaMetaMetaTestCase < MiniTest::Unit::TestCase
+  def assert_report expected, flags = %w[--seed 42]
+    header = clean <<-EOM
+      Run options: #{flags.map { |s| s =~ /\|/ ? s.inspect : s }.join " "}
+
+      # Running tests:
+
+    EOM
+
+    with_output do
+      @tu.run flags
+    end
+
+    output = @output.string.dup
+    output.sub!(/Finished tests in .*/, "Finished tests in 0.00")
+    output.sub!(/Loaded suite .*/, 'Loaded suite blah')
+
+    output.gsub!(/ = \d+.\d\d s = /, ' = 0.00 s = ')
+    output.gsub!(/0x[A-Fa-f0-9]+/, '0xXXX')
+
+    if windows? then
+      output.gsub!(/\[(?:[A-Za-z]:)?[^\]:]+:\d+\]/, '[FILE:LINE]')
+      output.gsub!(/^(\s+)(?:[A-Za-z]:)?[^:]+:\d+:in/, '\1FILE:LINE:in')
+    else
+      output.gsub!(/\[[^\]:]+:\d+\]/, '[FILE:LINE]')
+      output.gsub!(/^(\s+)[^:]+:\d+:in/, '\1FILE:LINE:in')
+    end
+
+    assert_equal header + expected, output
+  end
+
+  def setup
+    super
+    srand 42
+    MiniTest::Unit::TestCase.reset
+    @tu = MiniTest::Unit.new
+
+    MiniTest::Unit.runner = nil # protect the outer runner from the inner tests
+  end
+
+  def teardown
+    super
+  end
+
+  def with_output
+    synchronize do
+      begin
+        save = MiniTest::Unit.output
+        @output = StringIO.new("")
+        MiniTest::Unit.output = @output
+
+        yield
+      ensure
+        MiniTest::Unit.output = save
+      end
+    end
+  end
+end
diff --git a/tool/test/minitest/test_minitest_benchmark.rb b/tool/test/minitest/test_minitest_benchmark.rb
new file mode 100644
index 0000000000..a783e684c2
--- /dev/null
+++ b/tool/test/minitest/test_minitest_benchmark.rb
@@ -0,0 +1,131 @@
+# encoding: utf-8
+# frozen_string_literal: false
+
+require 'minitest/autorun'
+require 'minitest/benchmark'
+
+##
+# Used to verify data:
+# http://www.wolframalpha.com/examples/RegressionAnalysis.html
+
+class TestMiniTestBenchmark < MiniTest::Unit::TestCase
+  def test_cls_bench_exp
+    assert_equal [2, 4, 8, 16, 32], self.class.bench_exp(2, 32, 2)
+  end
+
+  def test_cls_bench_linear
+    assert_equal [2, 4, 6, 8, 10], self.class.bench_linear(2, 10, 2)
+  end
+
+  def test_cls_benchmark_methods
+    assert_equal [], self.class.benchmark_methods
+
+    c = Class.new(MiniTest::Unit::TestCase) do
+      def bench_blah
+      end
+    end
+
+    assert_equal ["bench_blah"], c.benchmark_methods
+  end
+
+  def test_cls_bench_range
+    assert_equal [1, 10, 100, 1_000, 10_000], self.class.bench_range
+  end
+
+  def test_fit_exponential_clean
+    x = [1.0, 2.0, 3.0, 4.0, 5.0]
+    y = x.map { |n| 1.1 * Math.exp(2.1 * n) }
+
+    assert_fit :exponential, x, y, 1.0, 1.1, 2.1
+  end
+
+  def test_fit_exponential_noisy
+    x = [1.0, 1.9, 2.6, 3.4, 5.0]
+    y = [12, 10, 8.2, 6.9, 5.9]
+
+    # verified with Numbers and R
+    assert_fit :exponential, x, y, 0.95, 13.81148, -0.1820
+  end
+
+  def test_fit_logarithmic_clean
+    x = [1.0, 2.0, 3.0, 4.0, 5.0]
+    y = x.map { |n| 1.1 + 2.1 * Math.log(n) }
+
+    assert_fit :logarithmic, x, y, 1.0, 1.1, 2.1
+  end
+
+  def test_fit_logarithmic_noisy
+    x = [1.0, 2.0, 3.0, 4.0, 5.0]
+    # Generated with
+    # y = x.map { |n| jitter = 0.999 + 0.002 * rand; (Math.log(n) ) * jitter }
+    y = [0.0, 0.6935, 1.0995, 1.3873, 1.6097]
+
+    assert_fit :logarithmic, x, y, 0.95, 0, 1
+  end
+
+  def test_fit_constant_clean
+    x = (1..5).to_a
+    y = [5.0, 5.0, 5.0, 5.0, 5.0]
+
+    assert_fit :linear, x, y, nil, 5.0, 0
+  end
+
+  def test_fit_constant_noisy
+    x = (1..5).to_a
+    y = [1.0, 1.2, 1.0, 0.8, 1.0]
+
+    # verified in numbers and R
+    assert_fit :linear, x, y, nil, 1.12, -0.04
+  end
+
+  def test_fit_linear_clean
+    # y = m * x + b where m = 2.2, b = 3.1
+    x = (1..5).to_a
+    y = x.map { |n| 2.2 * n + 3.1 }
+
+    assert_fit :linear, x, y, 1.0, 3.1, 2.2
+  end
+
+  def test_fit_linear_noisy
+    x = [ 60,  61,  62,  63,  65]
+    y = [3.1, 3.6, 3.8, 4.0, 4.1]
+
+    # verified in numbers and R
+    assert_fit :linear, x, y, 0.8315, -7.9635, 0.1878
+  end
+
+  def test_fit_power_clean
+    # y = A x ** B, where B = b and A = e ** a
+    # if, A = 1, B = 2, then
+
+    x = [1.0, 2.0, 3.0, 4.0, 5.0]
+    y = [1.0, 4.0, 9.0, 16.0, 25.0]
+
+    assert_fit :power, x, y, 1.0, 1.0, 2.0
+  end
+
+  def test_fit_power_noisy
+    # from www.engr.uidaho.edu/thompson/courses/ME330/lecture/least_squares.html
+    x = [10, 12, 15, 17, 20, 22, 25, 27, 30, 32, 35]
+    y = [95, 105, 125, 141, 173, 200, 253, 298, 385, 459, 602]
+
+    # verified in numbers
+    assert_fit :power, x, y, 0.90, 2.6217, 1.4556
+
+    # income to % of households below income amount
+    # http://library.wolfram.com/infocenter/Conferences/6461/PowerLaws.nb
+    x = [15000, 25000, 35000, 50000, 75000, 100000]
+    y = [0.154, 0.283, 0.402, 0.55, 0.733, 0.843]
+
+    # verified in numbers
+    assert_fit :power, x, y, 0.96, 3.119e-5, 0.8959
+  end
+
+  def assert_fit msg, x, y, fit, exp_a, exp_b
+    a, b, rr = send "fit_#{msg}", x, y
+
+    assert_operator rr, :>=, fit if fit
+    assert_in_delta exp_a, a
+    assert_in_delta exp_b, b
+  end
+end
diff --git a/tool/test/minitest/test_minitest_mock.rb b/tool/test/minitest/test_minitest_mock.rb
new file mode 100644
index 0000000000..6dcf39b75e
--- /dev/null
+++ b/tool/test/minitest/test_minitest_mock.rb
@@ -0,0 +1,404 @@
+# encoding: utf-8
+# frozen_string_literal: false
+
+require 'minitest/autorun'
+
+class TestMiniTestMock < MiniTest::Unit::TestCase
+  def setup
+    @mock = MiniTest::Mock.new.expect(:foo, nil)
+    @mock.expect(:meaning_of_life, 42)
+  end
+
+  def test_create_stub_method
+    assert_nil @mock.foo
+  end
+
+  def test_allow_return_value_specification
+    assert_equal 42, @mock.meaning_of_life
+  end
+
+  def test_blow_up_if_not_called
+    @mock.foo
+
+    util_verify_bad "expected meaning_of_life() => 42, got []"
+  end
+
+  def test_not_blow_up_if_everything_called
+    @mock.foo
+    @mock.meaning_of_life
+
+    assert @mock.verify
+  end
+
+  def test_allow_expectations_to_be_added_after_creation
+    @mock.expect(:bar, true)
+    assert @mock.bar
+  end
+
+  def test_not_verify_if_new_expected_method_is_not_called
+    @mock.foo
+    @mock.meaning_of_life
+    @mock.expect(:bar, true)
+
+    util_verify_bad "expected bar() => true, got []"
+  end
+
+  def test_blow_up_on_wrong_number_of_arguments
+    @mock.foo
+    @mock.meaning_of_life
+    @mock.expect(:sum, 3, [1, 2])
+
+    e = assert_raises ArgumentError do
+      @mock.sum
+    end
+
+    assert_equal "mocked method :sum expects 2 arguments, got 0", e.message
+  end
+
+  def test_return_mock_does_not_raise
+    retval = MiniTest::Mock.new
+    mock = MiniTest::Mock.new
+    mock.expect(:foo, retval)
+    mock.foo
+
+    assert mock.verify
+  end
+
+  def test_mock_args_does_not_raise
+    skip "non-opaque use of ==" if maglev?
+
+    arg = MiniTest::Mock.new
+    mock = MiniTest::Mock.new
+    mock.expect(:foo, nil, [arg])
+    mock.foo(arg)
+
+    assert mock.verify
+  end
+
+  def test_blow_up_on_wrong_arguments
+    @mock.foo
+    @mock.meaning_of_life
+    @mock.expect(:sum, 3, [1, 2])
+
+    e = assert_raises MockExpectationError do
+      @mock.sum(2, 4)
+    end
+
+    exp = "mocked method :sum called with unexpected arguments [2, 4]"
+    assert_equal exp, e.message
+  end
+
+  def test_expect_with_non_array_args
+    e = assert_raises ArgumentError do
+      @mock.expect :blah, 3, false
+    end
+
+    assert_equal "args must be an array", e.message
+  end
+
+  def test_respond_appropriately
+    assert @mock.respond_to?(:foo)
+    assert @mock.respond_to?(:foo, true)
+    assert @mock.respond_to?('foo')
+    assert !@mock.respond_to?(:bar)
+  end
+
+  def test_no_method_error_on_unexpected_methods
+    e = assert_raises NoMethodError do
+      @mock.bar
+    end
+
+    expected = "unmocked method :bar, expected one of [:foo, :meaning_of_life]"
+
+    assert_equal expected, e.message
+  end
+
+  def test_assign_per_mock_return_values
+    a = MiniTest::Mock.new
+    b = MiniTest::Mock.new
+
+    a.expect(:foo, :a)
+    b.expect(:foo, :b)
+
+    assert_equal :a, a.foo
+    assert_equal :b, b.foo
+  end
+
+  def test_do_not_create_stub_method_on_new_mocks
+    a = MiniTest::Mock.new
+    a.expect(:foo, :a)
+
+    assert !MiniTest::Mock.new.respond_to?(:foo)
+  end
+
+  def test_mock_is_a_blank_slate
+    @mock.expect :kind_of?, true, [Integer]
+    @mock.expect :==, true, [1]
+
+    assert @mock.kind_of?(Integer), "didn't mock :kind_of\?"
+    assert @mock == 1, "didn't mock :=="
+  end
+
+  def test_verify_allows_called_args_to_be_loosely_specified
+    mock = MiniTest::Mock.new
+    mock.expect :loose_expectation, true, [Integer]
+    mock.loose_expectation 1
+
+    assert mock.verify
+  end
+
+  def test_verify_raises_with_strict_args
+    mock = MiniTest::Mock.new
+    mock.expect :strict_expectation, true, [2]
+
+    e = assert_raises MockExpectationError do
+      mock.strict_expectation 1
+    end
+
+    exp = "mocked method :strict_expectation called with unexpected arguments [1]"
+    assert_equal exp, e.message
+  end
+
+  def test_method_missing_empty
+    mock = MiniTest::Mock.new
+
+    mock.expect :a, nil
+
+    mock.a
+
+    e = assert_raises MockExpectationError do
+      mock.a
+    end
+
+    assert_equal "No more expects available for :a: []", e.message
+  end
+
+  def test_same_method_expects_are_verified_when_all_called
+    mock = MiniTest::Mock.new
+    mock.expect :foo, nil, [:bar]
+    mock.expect :foo, nil, [:baz]
+
+    mock.foo :bar
+    mock.foo :baz
+
+    assert mock.verify
+  end
+
+  def test_same_method_expects_blow_up_when_not_all_called
+    mock = MiniTest::Mock.new
+    mock.expect :foo, nil, [:bar]
+    mock.expect :foo, nil, [:baz]
+
+    mock.foo :bar
+
+    e = assert_raises(MockExpectationError) { mock.verify }
+
+    exp = "expected foo(:baz) => nil, got [foo(:bar) => nil]"
+
+    assert_equal exp, e.message
+  end
+
+  def test_verify_passes_when_mock_block_returns_true
+    mock = MiniTest::Mock.new
+    mock.expect :foo, nil do
+      true
+    end
+
+    mock.foo
+
+    assert mock.verify
+  end
+
+  def test_mock_block_is_passed_function_params
+    arg1, arg2, arg3 = :bar, [1,2,3], {:a => 'a'}
+    mock = MiniTest::Mock.new
+    mock.expect :foo, nil do |a1, a2, a3|
+      a1 == arg1 &&
+      a2 == arg2 &&
+      a3 == arg3
+    end
+
+    mock.foo arg1, arg2, arg3
+
+    assert mock.verify
+  end
+
+  def test_verify_fails_when_mock_block_returns_false
+    mock = MiniTest::Mock.new
+    mock.expect :foo, nil do
+      false
+    end
+
+    e = assert_raises(MockExpectationError) { mock.foo }
+    exp = "mocked method :foo failed block w/ []"
+
+    assert_equal exp, e.message
+  end
+
+  def test_mock_block_throws_if_args_passed
+    mock = MiniTest::Mock.new
+
+    e = assert_raises(ArgumentError) do
+      mock.expect :foo, nil, [:a, :b, :c] do
+        true
+      end
+    end
+
+    exp = "args ignored when block given"
+
+    assert_equal exp, e.message
+  end
+
+  def test_mock_returns_retval_when_called_with_block
+    mock = MiniTest::Mock.new
+    mock.expect(:foo, 32) do
+      true
+    end
+
+    rs = mock.foo
+
+    assert_equal rs, 32
+  end
+
+  def util_verify_bad exp
+    e = assert_raises MockExpectationError do
+      @mock.verify
+    end
+
+    assert_equal exp, e.message
+  end
+end
+
+require "minitest/metametameta"
+
+class TestMiniTestStub < MiniTest::Unit::TestCase
+  def setup
+    super
+    MiniTest::Unit::TestCase.reset
+
+    @tc = MiniTest::Unit::TestCase.new 'fake tc'
+    @assertion_count = 1
+  end
+
+  def teardown
+    super
+    assert_equal @assertion_count, @tc._assertions
+  end
+
+  class Time
+    def self.now
+      24
+    end
+  end
+
+  def assert_stub val_or_callable
+    @assertion_count += 1
+
+    t = Time.now.to_i
+
+    Time.stub :now, val_or_callable do
+      @tc.assert_equal 42, Time.now
+    end
+
+    @tc.assert_operator Time.now.to_i, :>=, t
+  end
+
+  def test_stub_private_module_method
+    @assertion_count += 1
+
+    t0 = Time.now
+
+    self.stub :sleep, nil do
+      @tc.assert_nil sleep(10)
+    end
+
+    @tc.assert_operator Time.now - t0, :<=, 1
+  end
+
+  def test_stub_private_module_method_indirect
+    @assertion_count += 1
+
+    slow_clapper = Class.new do
+      def slow_clap
+        sleep 3
+        :clap
+      end
+    end.new
+
+    slow_clapper.stub :sleep, nil do |fast_clapper|
+      @tc.assert_equal :clap, fast_clapper.slow_clap # either form works
+      @tc.assert_equal :clap, slow_clapper.slow_clap # yay closures
+    end
+  end
+
+  def test_stub_public_module_method
+    Math.stub(:log10, 42.0) do
+      @tc.assert_in_delta 42.0, Math.log10(1000)
+    end
+  end
+
+  def test_stub_value
+    assert_stub 42
+  end
+
+  def test_stub_block
+    assert_stub lambda { 42 }
+  end
+
+  def test_stub_block_args
+    @assertion_count += 1
+
+    t = Time.now.to_i
+
+    Time.stub :now,  lambda { |n| n * 2 } do
+      @tc.assert_equal 42, Time.now(21)
+    end
+
+    @tc.assert_operator Time.now.to_i, :>=, t
+  end
+
+  def test_stub_callable
+    obj = Object.new
+
+    def obj.call
+      42
+    end
+
+    assert_stub obj
+  end
+
+  def test_stub_yield_self
+    obj = "foo"
+
+    val = obj.stub :to_s, "bar" do |s|
+      s.to_s
+    end
+
+    @tc.assert_equal "bar", val
+  end
+
+  def test_dynamic_method
+    @assertion_count = 2
+
+    dynamic = Class.new do
+      def self.respond_to?(meth)
+        meth == :found
+      end
+
+      def self.method_missing(meth, *args, &block)
+        if meth == :found
+          false
+        else
+          super
+        end
+      end
+    end
+
+    val = dynamic.stub(:found, true) do |s|
+      s.found
+    end
+
+    @tc.assert_equal true, val
+    @tc.assert_equal false, dynamic.found
+  end
+end
diff --git a/tool/test/minitest/test_minitest_unit.rb b/tool/test/minitest/test_minitest_unit.rb
new file mode 100644
index 0000000000..c6c8830f20
--- /dev/null
+++ b/tool/test/minitest/test_minitest_unit.rb
@@ -0,0 +1,1790 @@
+# encoding: utf-8
+# frozen_string_literal: false
+
+require 'pathname'
+require 'minitest/metametameta'
+
+module MyModule; end
+class AnError < StandardError; include MyModule; end
+class ImmutableString < String; def inspect; super.freeze; end; end
+
+class TestMiniTestUnit < MetaMetaMetaTestCase
+  pwd = Pathname.new File.expand_path Dir.pwd
+  basedir = Pathname.new(File.expand_path "lib/minitest") + 'mini'
+  basedir = basedir.relative_path_from(pwd).to_s
+  MINITEST_BASE_DIR = basedir[/\A\./] ? basedir : "./#{basedir}"
+  BT_MIDDLE = ["#{MINITEST_BASE_DIR}/test.rb:161:in `each'",
+               "#{MINITEST_BASE_DIR}/test.rb:158:in `each'",
+               "#{MINITEST_BASE_DIR}/test.rb:139:in `run'",
+               "#{MINITEST_BASE_DIR}/test.rb:106:in `run'"]
+
+  def test_class_puke_with_assertion_failed
+    exception = MiniTest::Assertion.new "Oh no!"
+    exception.set_backtrace ["unhappy"]
+    assert_equal 'F', @tu.puke('SomeClass', 'method_name', exception)
+    assert_equal 1, @tu.failures
+    assert_match(/^Failure.*Oh no!/m, @tu.report.first)
+    assert_match("SomeClass#method_name [unhappy]", @tu.report.first)
+  end
+
+  def test_class_puke_with_assertion_failed_and_long_backtrace
+    bt = (["test/test_some_class.rb:615:in `method_name'",
+           "#{MINITEST_BASE_DIR}/unit.rb:140:in `assert_raises'",
+           "test/test_some_class.rb:615:in `each'",
+           "test/test_some_class.rb:614:in `test_method_name'",
+           "#{MINITEST_BASE_DIR}/test.rb:165:in `__send__'"] +
+          BT_MIDDLE +
+          ["#{MINITEST_BASE_DIR}/test.rb:29"])
+    bt = util_expand_bt bt
+
+    ex_location = util_expand_bt(["test/test_some_class.rb:615"]).first
+
+    exception = MiniTest::Assertion.new "Oh no!"
+    exception.set_backtrace bt
+    assert_equal 'F', @tu.puke('TestSomeClass', 'test_method_name', exception)
+    assert_equal 1, @tu.failures
+    assert_match(/^Failure.*Oh no!/m, @tu.report.first)
+    assert_match("TestSomeClass#test_method_name [#{ex_location}]", @tu.report.first)
+  end
+
+  def test_class_puke_with_assertion_failed_and_user_defined_assertions
+    bt = (["lib/test/my/util.rb:16:in `another_method_name'",
+           "#{MINITEST_BASE_DIR}/unit.rb:140:in `assert_raises'",
+           "lib/test/my/util.rb:15:in `block in assert_something'",
+           "lib/test/my/util.rb:14:in `each'",
+           "lib/test/my/util.rb:14:in `assert_something'",
+           "test/test_some_class.rb:615:in `each'",
+           "test/test_some_class.rb:614:in `test_method_name'",
+           "#{MINITEST_BASE_DIR}/test.rb:165:in `__send__'"] +
+          BT_MIDDLE +
+          ["#{MINITEST_BASE_DIR}/test.rb:29"])
+    bt = util_expand_bt bt
+
+    ex_location = util_expand_bt(["test/test_some_class.rb:615"]).first
+
+    exception = MiniTest::Assertion.new "Oh no!"
+    exception.set_backtrace bt
+    assert_equal 'F', @tu.puke('TestSomeClass', 'test_method_name', exception)
+    assert_equal 1, @tu.failures
+    assert_match(/^Failure.*Oh no!/m, @tu.report.first)
+    assert_match("TestSomeClass#test_method_name [#{ex_location}]", @tu.report.first)
+  end
+
+  def test_class_puke_with_failure_and_flunk_in_backtrace
+    exception = begin
+                  MiniTest::Unit::TestCase.new('fake tc').flunk
+                rescue MiniTest::Assertion => failure
+                  failure
+                end
+    assert_equal 'F', @tu.puke('SomeClass', 'method_name', exception)
+    refute @tu.report.any?{|line| line =~ /in .flunk/}
+  end
+
+  def test_class_puke_with_flunk_and_user_defined_assertions
+    bt = (["lib/test/my/util.rb:16:in `flunk'",
+           "#{MINITEST_BASE_DIR}/unit.rb:140:in `assert_raises'",
+           "lib/test/my/util.rb:15:in `block in assert_something'",
+           "lib/test/my/util.rb:14:in `each'",
+           "lib/test/my/util.rb:14:in `assert_something'",
+           "test/test_some_class.rb:615:in `each'",
+           "test/test_some_class.rb:614:in `test_method_name'",
+           "#{MINITEST_BASE_DIR}/test.rb:165:in `__send__'"] +
+          BT_MIDDLE +
+          ["#{MINITEST_BASE_DIR}/test.rb:29"])
+    bt = util_expand_bt bt
+
+    ex_location = util_expand_bt(["test/test_some_class.rb:615"]).first
+
+    exception = MiniTest::Assertion.new "Oh no!"
+    exception.set_backtrace bt
+    assert_equal 'F', @tu.puke('TestSomeClass', 'test_method_name', exception)
+    assert_equal 1, @tu.failures
+    assert_match(/^Failure.*Oh no!/m, @tu.report.first)
+    assert_match("TestSomeClass#test_method_name [#{ex_location}]", @tu.report.first)
+  end
+
+  def test_class_puke_with_non_failure_exception
+    exception = Exception.new("Oh no again!")
+    assert_equal 'E', @tu.puke('SomeClass', 'method_name', exception)
+    assert_equal 1, @tu.errors
+    assert_match(/^Exception.*Oh no again!/m, @tu.report.first)
+  end
+
+  def test_filter_backtrace
+    # this is a semi-lame mix of relative paths.
+    # I cheated by making the autotest parts not have ./
+    bt = (["lib/autotest.rb:571:in `add_exception'",
+           "test/test_autotest.rb:62:in `test_add_exception'",
+           "#{MINITEST_BASE_DIR}/test.rb:165:in `__send__'"] +
+          BT_MIDDLE +
+          ["#{MINITEST_BASE_DIR}/test.rb:29",
+           "test/test_autotest.rb:422"])
+    bt = util_expand_bt bt
+
+    ex = ["lib/autotest.rb:571:in `add_exception'",
+          "test/test_autotest.rb:62:in `test_add_exception'"]
+    ex = util_expand_bt ex
+
+    fu = MiniTest::filter_backtrace(bt)
+
+    assert_equal ex, fu
+  end
+
+  def test_filter_backtrace_all_unit
+    bt = (["#{MINITEST_BASE_DIR}/test.rb:165:in `__send__'"] +
+          BT_MIDDLE +
+          ["#{MINITEST_BASE_DIR}/test.rb:29"])
+    ex = bt.clone
+    fu = MiniTest::filter_backtrace(bt)
+    assert_equal ex, fu
+  end
+
+  def test_filter_backtrace_unit_starts
+    bt = (["#{MINITEST_BASE_DIR}/test.rb:165:in `__send__'"] +
+          BT_MIDDLE +
+          ["#{MINITEST_BASE_DIR}/mini/test.rb:29",
+           "-e:1"])
+
+    bt = util_expand_bt bt
+
+    ex = ["-e:1"]
+    fu = MiniTest::filter_backtrace bt
+    assert_equal ex, fu
+  end
+
+  def test_default_runner_is_minitest_unit
+    assert_instance_of MiniTest::Unit, MiniTest::Unit.runner
+  end
+
+
+  def test_passed_eh_teardown_good
+    test_class = Class.new MiniTest::Unit::TestCase do
+      def teardown; assert true; end
+      def test_omg; assert true; end
+    end
+
+    test = test_class.new :test_omg
+    test.run @tu
+    assert test.passed?
+  end
+
+  def test_passed_eh_teardown_skipped
+    test_class = Class.new MiniTest::Unit::TestCase do
+      def teardown; assert true; end
+      def test_omg; skip "bork"; end
+    end
+
+    test = test_class.new :test_omg
+    test.run @tu
+    assert test.passed?
+  end
+
+  def test_passed_eh_teardown_flunked
+    test_class = Class.new MiniTest::Unit::TestCase do
+      def teardown; flunk;       end
+      def test_omg; assert true; end
+    end
+
+    test = test_class.new :test_omg
+    test.run @tu
+    refute test.passed?
+  end
+
+  def util_expand_bt bt
+    bt.map { |f| (f =~ /^\./) ? File.expand_path(f) : f }
+  end
+end
+
+class TestMiniTestUnitInherited < MetaMetaMetaTestCase
+  def with_overridden_include
+    Class.class_eval do
+      def inherited_with_hacks klass
+        throw :inherited_hook
+      end
+
+      alias inherited_without_hacks inherited
+      alias inherited               inherited_with_hacks
+      alias IGNORE_ME!              inherited # 1.8 bug. god I love venture bros
+    end
+
+    yield
+  ensure
+    Class.class_eval do
+      alias inherited inherited_without_hacks
+
+      undef_method :inherited_with_hacks
+      undef_method :inherited_without_hacks
+    end
+
+    refute_respond_to Class, :inherited_with_hacks
+    refute_respond_to Class, :inherited_without_hacks
+  end
+
+  def test_inherited_hook_plays_nice_with_others
+    with_overridden_include do
+      assert_throws :inherited_hook do
+        Class.new MiniTest::Unit::TestCase
+      end
+    end
+  end
+end
+
+class TestMiniTestRunner < MetaMetaMetaTestCase
+  # do not parallelize this suite... it just can't handle it.
+
+  def test_class_test_suites
+    @assertion_count = 0
+
+    tc = Class.new(MiniTest::Unit::TestCase)
+
+    assert_equal 1, MiniTest::Unit::TestCase.test_suites.size
+    assert_equal [tc], MiniTest::Unit::TestCase.test_suites
+  end
+
+  def test_run_test
+    Class.new MiniTest::Unit::TestCase do
+      attr_reader :foo
+
+      def run_test name
+        @foo = "hi mom!"
+        super
+        @foo = "okay"
+      end
+
+      def test_something
+        assert_equal "hi mom!", foo
+      end
+    end
+
+    expected = clean <<-EOM
+      .
+
+      Finished tests in 0.00
+
+      1 tests, 1 assertions, 0 failures, 0 errors, 0 skips
+    EOM
+
+    assert_report expected
+  end
+
+  def test_run_error
+    Class.new MiniTest::Unit::TestCase do
+      def test_something
+        assert true
+      end
+
+      def test_error
+        raise "unhandled exception"
+      end
+    end
+
+    expected = clean <<-EOM
+      E.
+
+      Finished tests in 0.00
+
+        1) Error:
+      #<Class:0xXXX>#test_error:
+      RuntimeError: unhandled exception
+          FILE:LINE:in \`test_error\'
+
+      2 tests, 1 assertions, 0 failures, 1 errors, 0 skips
+    EOM
+
+    assert_report expected
+  end
+
+  def test_run_error_teardown
+    Class.new MiniTest::Unit::TestCase do
+      def test_something
+        assert true
+      end
+
+      def teardown
+        raise "unhandled exception"
+      end
+    end
+
+    expected = clean <<-EOM
+      E
+
+      Finished tests in 0.00
+
+        1) Error:
+      #<Class:0xXXX>#test_something:
+      RuntimeError: unhandled exception
+          FILE:LINE:in \`teardown\'
+
+      1 tests, 1 assertions, 0 failures, 1 errors, 0 skips
+    EOM
+
+    assert_report expected
+  end
+
+  def test_run_failing
+    Class.new MiniTest::Unit::TestCase do
+      def test_something
+        assert true
+      end
+
+      def test_failure
+        assert false
+      end
+    end
+
+    expected = clean <<-EOM
+      F.
+
+      Finished tests in 0.00
+
+        1) Failure:
+      #<Class:0xXXX>#test_failure [FILE:LINE]:
+      Failed assertion, no message given.
+
+      2 tests, 2 assertions, 1 failures, 0 errors, 0 skips
+    EOM
+
+    assert_report expected
+  end
+
+  def test_run_failing_filtered
+    Class.new MiniTest::Unit::TestCase do
+      def test_something
+        assert true
+      end
+
+      def test_failure
+        assert false
+      end
+    end
+
+    expected = clean <<-EOM
+      .
+
+      Finished tests in 0.00
+
+      1 tests, 1 assertions, 0 failures, 0 errors, 0 skips
+    EOM
+
+    assert_report expected, %w[--name /some|thing/ --seed 42]
+  end
+
+  def assert_filtering name, expected, a = false
+    args = %W[--name #{name} --seed 42]
+
+    alpha = Class.new MiniTest::Unit::TestCase do
+      define_method :test_something do
+        assert a
+      end
+    end
+    Object.const_set(:Alpha, alpha)
+
+    beta = Class.new MiniTest::Unit::TestCase do
+      define_method :test_something do
+        assert true
+      end
+    end
+    Object.const_set(:Beta, beta)
+
+    assert_report expected, args
+  ensure
+    Object.send :remove_const, :Alpha
+    Object.send :remove_const, :Beta
+  end
+
+  def test_run_filtered_including_suite_name
+    expected = clean <<-EOM
+      .
+
+      Finished tests in 0.00
+
+      1 tests, 1 assertions, 0 failures, 0 errors, 0 skips
+    EOM
+
+    assert_filtering "/Beta#test_something/", expected
+  end
+
+  def test_run_filtered_including_suite_name_string
+    expected = clean <<-EOM
+      .
+
+      Finished tests in 0.00
+
+      1 tests, 1 assertions, 0 failures, 0 errors, 0 skips
+    EOM
+
+    assert_filtering "Beta#test_something", expected
+  end
+
+  def test_run_filtered_string_method_only
+    expected = clean <<-EOM
+      ..
+
+      Finished tests in 0.00
+
+      2 tests, 2 assertions, 0 failures, 0 errors, 0 skips
+    EOM
+
+    assert_filtering "test_something", expected, :pass
+  end
+
+  def test_run_passing
+    Class.new MiniTest::Unit::TestCase do
+      def test_something
+        assert true
+      end
+    end
+
+    expected = clean <<-EOM
+      .
+
+      Finished tests in 0.00
+
+      1 tests, 1 assertions, 0 failures, 0 errors, 0 skips
+    EOM
+
+    assert_report expected
+  end
+
+  def test_run_skip
+    Class.new MiniTest::Unit::TestCase do
+      def test_something
+        assert true
+      end
+
+      def test_skip
+        skip "not yet"
+      end
+    end
+
+    expected = clean <<-EOM
+      S.
+
+      Finished tests in 0.00
+
+      2 tests, 1 assertions, 0 failures, 0 errors, 1 skips
+    EOM
+
+    assert_report expected
+  end
+
+  def test_run_skip_verbose
+    Class.new MiniTest::Unit::TestCase do
+      def test_something
+        assert true
+      end
+
+      def test_skip
+        skip "not yet"
+      end
+    end
+
+    expected = clean <<-EOM
+      #<Class:0xXXX>#test_skip = 0.00 s = S
+      #<Class:0xXXX>#test_something = 0.00 s = .
+
+
+      Finished tests in 0.00
+
+        1) Skipped:
+      #<Class:0xXXX>#test_skip [FILE:LINE]:
+      not yet
+
+      2 tests, 1 assertions, 0 failures, 0 errors, 1 skips
+    EOM
+
+    assert_report expected, %w[--seed 42 --verbose]
+  end
+
+  def test_run_with_other_runner
+    MiniTest::Unit.runner = Class.new MiniTest::Unit do
+      def _run_suite suite, type
+        suite.before_suite # Run once before each suite
+        super suite, type
+      end
+    end.new
+
+    Class.new MiniTest::Unit::TestCase do
+      def self.name; "wacky!" end
+
+      def self.before_suite
+        MiniTest::Unit.output.puts "Running #{self.name} tests"
+        @@foo = 1
+      end
+
+      def test_something
+        assert_equal 1, @@foo
+      end
+
+      def test_something_else
+        assert_equal 1, @@foo
+      end
+    end
+
+    expected = clean <<-EOM
+      Running wacky! tests
+      ..
+
+      Finished tests in 0.00
+
+      2 tests, 2 assertions, 0 failures, 0 errors, 0 skips
+    EOM
+
+    assert_report expected
+  end
+
+  require 'monitor'
+
+  class Latch
+    def initialize count = 1
+      @count = count
+      @lock  = Monitor.new
+      @cv    = @lock.new_cond
+    end
+
+    def release
+      @lock.synchronize do
+        @count -= 1 if @count > 0
+        @cv.broadcast if @count == 0
+      end
+    end
+
+    def await
+      @lock.synchronize { @cv.wait_while { @count > 0 } }
+    end
+  end
+end
+
+class TestMiniTestUnitOrder < MetaMetaMetaTestCase
+  # do not parallelize this suite... it just can't handle it.
+
+  def test_before_setup
+    call_order = []
+    Class.new MiniTest::Unit::TestCase do
+      define_method :setup do
+        super()
+        call_order << :setup
+      end
+
+      define_method :before_setup do
+        call_order << :before_setup
+      end
+
+      def test_omg; assert true; end
+    end
+
+    with_output do
+      @tu.run %w[--seed 42]
+    end
+
+    expected = [:before_setup, :setup]
+    assert_equal expected, call_order
+  end
+
+  def test_after_teardown
+    call_order = []
+    Class.new MiniTest::Unit::TestCase do
+      define_method :teardown do
+        super()
+        call_order << :teardown
+      end
+
+      define_method :after_teardown do
+        call_order << :after_teardown
+      end
+
+      def test_omg; assert true; end
+    end
+
+    with_output do
+      @tu.run %w[--seed 42]
+    end
+
+    expected = [:teardown, :after_teardown]
+    assert_equal expected, call_order
+  end
+
+  def test_all_teardowns_are_guaranteed_to_run
+    call_order = []
+    Class.new MiniTest::Unit::TestCase do
+      define_method :after_teardown do
+        super()
+        call_order << :after_teardown
+        raise
+      end
+
+      define_method :teardown do
+        super()
+        call_order << :teardown
+        raise
+      end
+
+      define_method :before_teardown do
+        super()
+        call_order << :before_teardown
+        raise
+      end
+
+      def test_omg; assert true; end
+    end
+
+    with_output do
+      @tu.run %w[--seed 42]
+    end
+
+    expected = [:before_teardown, :teardown, :after_teardown]
+    assert_equal expected, call_order
+  end
+
+  def test_setup_and_teardown_survive_inheritance
+    call_order = []
+
+    parent = Class.new MiniTest::Unit::TestCase do
+      define_method :setup do
+        call_order << :setup_method
+      end
+
+      define_method :teardown do
+        call_order << :teardown_method
+      end
+
+      define_method :test_something do
+        call_order << :test
+      end
+    end
+
+    _ = Class.new parent
+
+    with_output do
+      @tu.run %w[--seed 42]
+    end
+
+    # Once for the parent class, once for the child
+    expected = [:setup_method, :test, :teardown_method] * 2
+
+    assert_equal expected, call_order
+  end
+end
+
+class TestMiniTestUnitTestCase < MiniTest::Unit::TestCase
+  # do not call parallelize_me! - teardown accesses @tc._assertions
+  # which is not threadsafe. Nearly every method in here is an
+  # assertion test so it isn't worth splitting it out further.
+
+  RUBY18 = ! defined? Encoding
+
+  def setup
+    super
+
+    MiniTest::Unit::TestCase.reset
+
+    @tc = MiniTest::Unit::TestCase.new 'fake tc'
+    @zomg = "zomg ponies!"
+    @assertion_count = 1
+  end
+
+  def teardown
+    assert_equal(@assertion_count, @tc._assertions,
+                 "expected #{@assertion_count} assertions to be fired during the test, not #{@tc._assertions}") if @tc.passed?
+  end
+
+  def non_verbose
+    orig_verbose = $VERBOSE
+    $VERBOSE = false
+
+    yield
+  ensure
+    $VERBOSE = orig_verbose
+  end
+
+  def test_assert
+    @assertion_count = 2
+
+    @tc.assert_equal true, @tc.assert(true), "returns true on success"
+  end
+
+  def test_assert__triggered
+    util_assert_triggered "Failed assertion, no message given." do
+      @tc.assert false
+    end
+  end
+
+  def test_assert__triggered_message
+    util_assert_triggered @zomg do
+      @tc.assert false, @zomg
+    end
+  end
+
+  def test_assert_empty
+    @assertion_count = 2
+
+    @tc.assert_empty []
+  end
+
+  def test_assert_empty_triggered
+    @assertion_count = 2
+
+    util_assert_triggered "Expected [1] to be empty." do
+      @tc.assert_empty [1]
+    end
+  end
+
+  def test_assert_equal
+    @tc.assert_equal 1, 1
+  end
+
+  def test_assert_equal_different_collection_array_hex_invisible
+    object1 = Object.new
+    object2 = Object.new
+    msg = "No visible difference in the Array#inspect output.
+           You should look at the implementation of #== on Array or its members.
+           [#<Object:0xXXXXXX>]".gsub(/^ +/, "")
+    util_assert_triggered msg do
+      @tc.assert_equal [object1], [object2]
+    end
+  end
+
+  def test_assert_equal_different_collection_hash_hex_invisible
+    h1, h2 = {}, {}
+    h1[1] = Object.new
+    h2[1] = Object.new
+    msg = "No visible difference in the Hash#inspect output.
+           You should look at the implementation of #== on Hash or its members.
+           {1=>#<Object:0xXXXXXX>}".gsub(/^ +/, "")
+
+    util_assert_triggered msg do
+      @tc.assert_equal h1, h2
+    end
+  end
+
+  def test_assert_equal_different_diff_deactivated
+    skip "https://github.com/MagLev/maglev/issues/209" if maglev?
+
+    without_diff do
+      util_assert_triggered util_msg("haha" * 10, "blah" * 10) do
+        o1 = "haha" * 10
+        o2 = "blah" * 10
+
+        @tc.assert_equal o1, o2
+      end
+    end
+  end
+
+  def test_assert_equal_different_hex
+    c = Class.new do
+      def initialize s; @name = s; end
+    end
+
+    o1 = c.new "a"
+    o2 = c.new "b"
+    msg = "--- expected
+           +++ actual
+           @@ -1 +1 @@
+           -#<#<Class:0xXXXXXX>:0xXXXXXX @name=\"a\">
+           +#<#<Class:0xXXXXXX>:0xXXXXXX @name=\"b\">
+           ".gsub(/^ +/, "")
+
+    util_assert_triggered msg do
+      @tc.assert_equal o1, o2
+    end
+  end
+
+  def test_assert_equal_different_hex_invisible
+    o1 = Object.new
+    o2 = Object.new
+
+    msg = "No visible difference in the Object#inspect output.
+           You should look at the implementation of #== on Object or its members.
+           #<Object:0xXXXXXX>".gsub(/^ +/, "")
+
+    util_assert_triggered msg do
+      @tc.assert_equal o1, o2
+    end
+  end
+
+  def test_assert_equal_different_long
+    msg = "--- expected
+           +++ actual
+           @@ -1 +1 @@
+           -\"hahahahahahahahahahahahahahahahahahahaha\"
+           +\"blahblahblahblahblahblahblahblahblahblah\"
+           ".gsub(/^ +/, "")
+
+    util_assert_triggered msg do
+      o1 = "haha" * 10
+      o2 = "blah" * 10
+
+      @tc.assert_equal o1, o2
+    end
+  end
+
+  def test_assert_equal_different_long_invisible
+    msg = "No visible difference in the String#inspect output.
+           You should look at the implementation of #== on String or its members.
+           \"blahblahblahblahblahblahblahblahblahblah\"".gsub(/^ +/, "")
+
+    util_assert_triggered msg do
+      o1 = "blah" * 10
+      o2 = "blah" * 10
+      def o1.== o
+        false
+      end
+      @tc.assert_equal o1, o2
+    end
+  end
+
+  def test_assert_equal_different_long_msg
+    msg = "message.
+           --- expected
+           +++ actual
+           @@ -1 +1 @@
+           -\"hahahahahahahahahahahahahahahahahahahaha\"
+           +\"blahblahblahblahblahblahblahblahblahblah\"
+           ".gsub(/^ +/, "")
+
+    util_assert_triggered msg do
+      o1 = "haha" * 10
+      o2 = "blah" * 10
+      @tc.assert_equal o1, o2, "message"
+    end
+  end
+
+  def test_assert_equal_different_short
+    util_assert_triggered util_msg(1, 2) do
+      @tc.assert_equal 1, 2
+    end
+  end
+
+  def test_assert_equal_different_short_msg
+    util_assert_triggered util_msg(1, 2, "message") do
+      @tc.assert_equal 1, 2, "message"
+    end
+  end
+
+  def test_assert_equal_different_short_multiline
+    msg = "--- expected\n+++ actual\n@@ -1,2 +1,2 @@\n \"a\n-b\"\n+c\"\n"
+    util_assert_triggered msg do
+      @tc.assert_equal "a\nb", "a\nc"
+    end
+  end
+
+  def test_assert_equal_different_escaped_newline
+    msg = "--- expected\n+++ actual\n@@ -1,2 +1,2 @@\n \"xxx\n-a\\\\nb\"\n+a\\\\nc\"\n"
+    util_assert_triggered msg do
+      @tc.assert_equal "xxx\na\\nb", "xxx\na\\nc"
+    end
+  end
+
+  def test_assert_in_delta
+    @tc.assert_in_delta 0.0, 1.0 / 1000, 0.1
+  end
+
+  def test_delta_consistency
+    @tc.assert_in_delta 0, 1, 1
+
+    util_assert_triggered "Expected |0 - 1| (1) to not be <= 1." do
+      @tc.refute_in_delta 0, 1, 1
+    end
+  end
+
+  def test_assert_in_delta_triggered
+    x = maglev? ? "9.999999xxxe-07" : "1.0e-06"
+    util_assert_triggered "Expected |0.0 - 0.001| (0.001) to be <= #{x}." do
+      @tc.assert_in_delta 0.0, 1.0 / 1000, 0.000001
+    end
+  end
+
+  def test_assert_in_epsilon
+    @assertion_count = 10
+
+    @tc.assert_in_epsilon 10000, 9991
+    @tc.assert_in_epsilon 9991, 10000
+    @tc.assert_in_epsilon 1.0, 1.001
+    @tc.assert_in_epsilon 1.001, 1.0
+
+    @tc.assert_in_epsilon 10000, 9999.1, 0.0001
+    @tc.assert_in_epsilon 9999.1, 10000, 0.0001
+    @tc.assert_in_epsilon 1.0, 1.0001, 0.0001
+    @tc.assert_in_epsilon 1.0001, 1.0, 0.0001
+
+    @tc.assert_in_epsilon(-1, -1)
+    @tc.assert_in_epsilon(-10000, -9991)
+  end
+
+  def test_epsilon_consistency
+    @tc.assert_in_epsilon 1.0, 1.001
+
+    msg = "Expected |1.0 - 1.001| (0.000999xxx) to not be <= 0.001."
+    util_assert_triggered msg do
+      @tc.refute_in_epsilon 1.0, 1.001
+    end
+  end
+
+  def test_assert_in_epsilon_triggered
+    util_assert_triggered 'Expected |10000 - 9990| (10) to be <= 9.99.' do
+      @tc.assert_in_epsilon 10000, 9990
+    end
+  end
+
+  def test_assert_in_epsilon_triggered_negative_case
+    x = (RUBY18 and not maglev?) ? "0.1" : "0.100000xxx"
+    y = maglev? ? "0.100000xxx" : "0.1"
+    util_assert_triggered "Expected |-1.1 - -1| (#{x}) to be <= #{y}." do
+      @tc.assert_in_epsilon(-1.1, -1, 0.1)
+    end
+  end
+
+  def test_assert_includes
+    @assertion_count = 2
+
+    @tc.assert_includes [true], true
+  end
+
+  def test_assert_includes_triggered
+    @assertion_count = 3
+
+    e = @tc.assert_raises MiniTest::Assertion do
+      @tc.assert_includes [true], false
+    end
+
+    expected = "Expected [true] to include false."
+    assert_equal expected, e.message
+  end
+
+  def test_assert_instance_of
+    @tc.assert_instance_of String, "blah"
+  end
+
+  def test_assert_instance_of_triggered
+    util_assert_triggered 'Expected "blah" to be an instance of Array, not String.' do
+      @tc.assert_instance_of Array, "blah"
+    end
+  end
+
+  def test_assert_kind_of
+    @tc.assert_kind_of String, "blah"
+  end
+
+  def test_assert_kind_of_triggered
+    util_assert_triggered 'Expected "blah" to be a kind of Array, not String.' do
+      @tc.assert_kind_of Array, "blah"
+    end
+  end
+
+  def test_assert_match
+    @assertion_count = 2
+    @tc.assert_match(/\w+/, "blah blah blah")
+  end
+
+  def test_assert_match_matcher_object
+    @assertion_count = 2
+
+    pattern = Object.new
+    def pattern.=~(other) true end
+
+    @tc.assert_match pattern, 5
+  end
+
+  def test_assert_match_matchee_to_str
+    @assertion_count = 2
+
+    obj = Object.new
+    def obj.to_str; "blah" end
+
+    @tc.assert_match "blah", obj
+  end
+
+  def test_assert_match_object_triggered
+    @assertion_count = 2
+
+    pattern = Object.new
+    def pattern.=~(other) false end
+    def pattern.inspect; "[Object]" end
+
+    util_assert_triggered 'Expected [Object] to match 5.' do
+      @tc.assert_match pattern, 5
+    end
+  end
+
+  def test_assert_match_triggered
+    @assertion_count = 2
+    util_assert_triggered 'Expected /\d+/ to match "blah blah blah".' do
+      @tc.assert_match(/\d+/, "blah blah blah")
+    end
+  end
+
+  def test_assert_nil
+    @tc.assert_nil nil
+  end
+
+  def test_assert_nil_triggered
+    util_assert_triggered 'Expected 42 to be nil.' do
+      @tc.assert_nil 42
+    end
+  end
+
+  def test_assert_operator
+    @tc.assert_operator 2, :>, 1
+  end
+
+  def test_assert_operator_bad_object
+    bad = Object.new
+    def bad.==(other) true end
+
+    @tc.assert_operator bad, :equal?, bad
+  end
+
+  def test_assert_operator_triggered
+    util_assert_triggered "Expected 2 to be < 1." do
+      @tc.assert_operator 2, :<, 1
+    end
+  end
+
+  def test_assert_output_both
+    @assertion_count = 2
+
+    @tc.assert_output "yay", "blah" do
+      print "yay"
+      $stderr.print "blah"
+    end
+  end
+
+  def test_assert_output_both_regexps
+    @assertion_count = 4
+
+    @tc.assert_output(/y.y/, /bl.h/) do
+      print "yay"
+      $stderr.print "blah"
+    end
+  end
+
+  def test_assert_output_err
+    @tc.assert_output nil, "blah" do
+      $stderr.print "blah"
+    end
+  end
+
+  def test_assert_output_neither
+    @assertion_count = 0
+
+    @tc.assert_output do
+      # do nothing
+    end
+  end
+
+  def test_assert_output_out
+    @tc.assert_output "blah" do
+      print "blah"
+    end
+  end
+
+  def test_assert_output_triggered_both
+    util_assert_triggered util_msg("blah", "blah blah", "In stderr") do
+      @tc.assert_output "yay", "blah" do
+        print "boo"
+        $stderr.print "blah blah"
+      end
+    end
+  end
+
+  def test_assert_output_triggered_err
+    util_assert_triggered util_msg("blah", "blah blah", "In stderr") do
+      @tc.assert_output nil, "blah" do
+        $stderr.print "blah blah"
+      end
+    end
+  end
+
+  def test_assert_output_triggered_out
+    util_assert_triggered util_msg("blah", "blah blah", "In stdout") do
+      @tc.assert_output "blah" do
+        print "blah blah"
+      end
+    end
+  end
+
+  def test_assert_predicate
+    @tc.assert_predicate "", :empty?
+  end
+
+  def test_assert_predicate_triggered
+    util_assert_triggered 'Expected "blah" to be empty?.' do
+      @tc.assert_predicate "blah", :empty?
+    end
+  end
+
+  def test_assert_raises
+    @tc.assert_raises RuntimeError do
+      raise "blah"
+    end
+  end
+
+  def test_assert_raises_module
+    @tc.assert_raises MyModule do
+      raise AnError
+    end
+  end
+
+  ##
+  # *sigh* This is quite an odd scenario, but it is from real (albeit
+  # ugly) test code in ruby-core:
+  #
+  # https://github.com/ruby/ruby/commit/6bab4ea9917dc05cd2c94aead2e96eb7df7d4be1
+
+  def test_assert_raises_skip
+    @assertion_count = 0
+
+    util_assert_triggered "skipped", MiniTest::Skip do
+      @tc.assert_raises ArgumentError do
+        begin
+          raise "blah"
+        rescue
+          skip "skipped"
+        end
+      end
+    end
+  end
+
+  def test_assert_raises_triggered_different
+    e = assert_raises MiniTest::Assertion do
+      @tc.assert_raises RuntimeError do
+        raise SyntaxError, "icky"
+      end
+    end
+
+    expected = clean <<-EOM.chomp
+      [RuntimeError] exception expected, not
+      Class: <SyntaxError>
+      Message: <\"icky\">
+      ---Backtrace---
+      FILE:LINE:in \`test_assert_raises_triggered_different\'
+      ---------------
+    EOM
+
+    actual = e.message.gsub(/^.+:\d+/, 'FILE:LINE')
+    actual.gsub!(/block \(\d+ levels\) in /, '') if RUBY_VERSION >= '1.9.0'
+
+    assert_equal expected, actual
+  end
+
+  def test_assert_raises_triggered_different_msg
+    e = assert_raises MiniTest::Assertion do
+      @tc.assert_raises RuntimeError, "XXX" do
+        raise SyntaxError, "icky"
+      end
+    end
+
+    expected = clean <<-EOM
+      XXX.
+      [RuntimeError] exception expected, not
+      Class: <SyntaxError>
+      Message: <\"icky\">
+      ---Backtrace---
+      FILE:LINE:in \`test_assert_raises_triggered_different_msg\'
+      ---------------
+    EOM
+
+    actual = e.message.gsub(/^.+:\d+/, 'FILE:LINE')
+    actual.gsub!(/block \(\d+ levels\) in /, '') if RUBY_VERSION >= '1.9.0'
+
+    assert_equal expected.chomp, actual
+  end
+
+  def test_assert_raises_triggered_none
+    e = assert_raises MiniTest::Assertion do
+      @tc.assert_raises MiniTest::Assertion do
+        # do nothing
+      end
+    end
+
+    expected = "MiniTest::Assertion expected but nothing was raised."
+
+    assert_equal expected, e.message
+  end
+
+  def test_assert_raises_triggered_none_msg
+    e = assert_raises MiniTest::Assertion do
+      @tc.assert_raises MiniTest::Assertion, "XXX" do
+        # do nothing
+      end
+    end
+
+    expected = "XXX.\nMiniTest::Assertion expected but nothing was raised."
+
+    assert_equal expected, e.message
+  end
+
+  def test_assert_raises_triggered_subclass
+    e = assert_raises MiniTest::Assertion do
+      @tc.assert_raises StandardError do
+        raise AnError
+      end
+    end
+
+    expected = clean <<-EOM.chomp
+      [StandardError] exception expected, not
+      Class: <AnError>
+      Message: <\"AnError\">
+      ---Backtrace---
+      FILE:LINE:in \`test_assert_raises_triggered_subclass\'
+      ---------------
+    EOM
+
+    actual = e.message.gsub(/^.+:\d+/, 'FILE:LINE')
+    actual.gsub!(/block \(\d+ levels\) in /, '') if RUBY_VERSION >= '1.9.0'
+
+    assert_equal expected, actual
+  end
+
+  def test_assert_respond_to
+    @tc.assert_respond_to "blah", :empty?
+  end
+
+  def test_assert_respond_to_triggered
+    util_assert_triggered 'Expected "blah" (String) to respond to #rawr!.' do
+      @tc.assert_respond_to "blah", :rawr!
+    end
+  end
+
+  def test_assert_same
+    @assertion_count = 3
+
+    o = "blah"
+    @tc.assert_same 1, 1
+    @tc.assert_same :blah, :blah
+    @tc.assert_same o, o
+  end
+
+  def test_assert_same_triggered
+    @assertion_count = 2
+
+    util_assert_triggered 'Expected 2 (oid=N) to be the same as 1 (oid=N).' do
+      @tc.assert_same 1, 2
+    end
+
+    s1 = "blah"
+    s2 = "blah"
+
+    util_assert_triggered 'Expected "blah" (oid=N) to be the same as "blah" (oid=N).' do
+      @tc.assert_same s1, s2
+    end
+  end
+
+  def test_assert_send
+    @tc.assert_send [1, :<, 2]
+  end
+
+  def test_assert_send_bad
+    util_assert_triggered "Expected 1.>(*[2]) to return true." do
+      @tc.assert_send [1, :>, 2]
+    end
+  end
+
+  def test_assert_silent
+    @assertion_count = 2
+
+    @tc.assert_silent do
+      # do nothing
+    end
+  end
+
+  def test_assert_silent_triggered_err
+    util_assert_triggered util_msg("", "blah blah", "In stderr") do
+      @tc.assert_silent do
+        $stderr.print "blah blah"
+      end
+    end
+  end
+
+  def test_assert_silent_triggered_out
+    @assertion_count = 2
+
+    util_assert_triggered util_msg("", "blah blah", "In stdout") do
+      @tc.assert_silent do
+        print "blah blah"
+      end
+    end
+  end
+
+  def test_assert_throws
+    @tc.assert_throws :blah do
+      throw :blah
+    end
+  end
+
+  def test_assert_throws_different
+    util_assert_triggered 'Expected :blah to have been thrown, not :not_blah.' do
+      @tc.assert_throws :blah do
+        throw :not_blah
+      end
+    end
+  end
+
+  def test_assert_throws_unthrown
+    util_assert_triggered 'Expected :blah to have been thrown.' do
+      @tc.assert_throws :blah do
+        # do nothing
+      end
+    end
+  end
+
+  def test_capture_io
+    @assertion_count = 0
+
+    non_verbose do
+      out, err = capture_io do
+        puts 'hi'
+        $stderr.puts 'bye!'
+      end
+
+      assert_equal "hi\n", out
+      assert_equal "bye!\n", err
+    end
+  end
+
+  def test_capture_subprocess_io
+    @assertion_count = 0
+
+    non_verbose do
+      out, err = capture_subprocess_io do
+        system("echo", "hi")
+        system("echo", "bye!", out: :err)
+      end
+
+      assert_equal "hi\n", out
+      assert_equal "bye!\n", err
+    end
+  end
+
+  def test_class_asserts_match_refutes
+    @assertion_count = 0
+
+    methods = MiniTest::Assertions.public_instance_methods
+    methods.map! { |m| m.to_s } if Symbol === methods.first
+
+    # These don't have corresponding refutes _on purpose_. They're
+    # useless and will never be added, so don't bother.
+    ignores = %w[assert_output assert_raises assert_send
+                 assert_silent assert_throws]
+
+    # These are test/unit methods. I'm not actually sure why they're still here
+    ignores += %w[assert_no_match assert_not_equal assert_not_nil
+                  assert_not_same assert_nothing_raised
+                  assert_nothing_thrown assert_raise]
+
+    asserts = methods.grep(/^assert/).sort - ignores
+    refutes = methods.grep(/^refute/).sort - ignores
+
+    assert_empty refutes.map { |n| n.sub(/^refute/, 'assert') } - asserts
+    assert_empty asserts.map { |n| n.sub(/^assert/, 'refute') } - refutes
+  end
+
+  def test_flunk
+    util_assert_triggered 'Epic Fail!' do
+      @tc.flunk
+    end
+  end
+
+  def test_flunk_message
+    util_assert_triggered @zomg do
+      @tc.flunk @zomg
+    end
+  end
+
+  def test_message
+    @assertion_count = 0
+
+    assert_equal "blah2.",         @tc.message          { "blah2" }.call
+    assert_equal "blah2.",         @tc.message("")      { "blah2" }.call
+    assert_equal "blah1.\nblah2.", @tc.message(:blah1)  { "blah2" }.call
+    assert_equal "blah1.\nblah2.", @tc.message("blah1") { "blah2" }.call
+
+    message = proc { "blah1" }
+    assert_equal "blah1.\nblah2.", @tc.message(message) { "blah2" }.call
+
+    message = @tc.message { "blah1" }
+    assert_equal "blah1.\nblah2.", @tc.message(message) { "blah2" }.call
+  end
+
+  def test_message_message
+    util_assert_triggered "whoops.\nExpected: 1\n  Actual: 2" do
+      @tc.assert_equal 1, 2, message { "whoops" }
+    end
+  end
+
+  def test_message_lambda
+    util_assert_triggered "whoops.\nExpected: 1\n  Actual: 2" do
+      @tc.assert_equal 1, 2, lambda { "whoops" }
+    end
+  end
+
+  def test_message_deferred
+    @assertion_count, var = 0, nil
+
+    msg = message { var = "blah" }
+
+    assert_nil var
+
+    msg.call
+
+    assert_equal "blah", var
+  end
+
+  def test_pass
+    @tc.pass
+  end
+
+  def test_prints
+    printer = Class.new { extend MiniTest::Assertions }
+    @tc.assert_equal '"test"', printer.mu_pp(ImmutableString.new 'test')
+  end
+
+  def test_refute
+    @assertion_count = 2
+
+    @tc.assert_equal false, @tc.refute(false), "returns false on success"
+  end
+
+  def test_refute_empty
+    @assertion_count = 2
+
+    @tc.refute_empty [1]
+  end
+
+  def test_refute_empty_triggered
+    @assertion_count = 2
+
+    util_assert_triggered "Expected [] to not be empty." do
+      @tc.refute_empty []
+    end
+  end
+
+  def test_refute_equal
+    @tc.refute_equal "blah", "yay"
+  end
+
+  def test_refute_equal_triggered
+    util_assert_triggered 'Expected "blah" to not be equal to "blah".' do
+      @tc.refute_equal "blah", "blah"
+    end
+  end
+
+  def test_refute_in_delta
+    @tc.refute_in_delta 0.0, 1.0 / 1000, 0.000001
+  end
+
+  def test_refute_in_delta_triggered
+    x = maglev? ? "0.100000xxx" : "0.1"
+    util_assert_triggered "Expected |0.0 - 0.001| (0.001) to not be <= #{x}." do
+      @tc.refute_in_delta 0.0, 1.0 / 1000, 0.1
+    end
+  end
+
+  def test_refute_in_epsilon
+    @tc.refute_in_epsilon 10000, 9990-1
+  end
+
+  def test_refute_in_epsilon_triggered
+    util_assert_triggered 'Expected |10000 - 9990| (10) to not be <= 10.0.' do
+      @tc.refute_in_epsilon 10000, 9990
+      fail
+    end
+  end
+
+  def test_refute_includes
+    @assertion_count = 2
+
+    @tc.refute_includes [true], false
+  end
+
+  def test_refute_includes_triggered
+    @assertion_count = 3
+
+    e = @tc.assert_raises MiniTest::Assertion do
+      @tc.refute_includes [true], true
+    end
+
+    expected = "Expected [true] to not include true."
+    assert_equal expected, e.message
+  end
+
+  def test_refute_instance_of
+    @tc.refute_instance_of Array, "blah"
+  end
+
+  def test_refute_instance_of_triggered
+    util_assert_triggered 'Expected "blah" to not be an instance of String.' do
+      @tc.refute_instance_of String, "blah"
+    end
+  end
+
+  def test_refute_kind_of
+    @tc.refute_kind_of Array, "blah"
+  end
+
+  def test_refute_kind_of_triggered
+    util_assert_triggered 'Expected "blah" to not be a kind of String.' do
+      @tc.refute_kind_of String, "blah"
+    end
+  end
+
+  def test_refute_match
+    @assertion_count = 2
+    @tc.refute_match(/\d+/, "blah blah blah")
+  end
+
+  def test_refute_match_matcher_object
+    @assertion_count = 2
+    non_verbose do
+      obj = Object.new
+      def obj.=~(other); false; end
+      @tc.refute_match obj, 5
+    end
+  end
+
+  def test_refute_match_object_triggered
+    @assertion_count = 2
+
+    pattern = Object.new
+    def pattern.=~(other) true end
+    def pattern.inspect; "[Object]" end
+
+    util_assert_triggered 'Expected [Object] to not match 5.' do
+      @tc.refute_match pattern, 5
+    end
+  end
+
+  def test_refute_match_triggered
+    @assertion_count = 2
+    util_assert_triggered 'Expected /\w+/ to not match "blah blah blah".' do
+      @tc.refute_match(/\w+/, "blah blah blah")
+    end
+  end
+
+  def test_refute_nil
+    @tc.refute_nil 42
+  end
+
+  def test_refute_nil_triggered
+    util_assert_triggered 'Expected nil to not be nil.' do
+      @tc.refute_nil nil
+    end
+  end
+
+  def test_refute_predicate
+    @tc.refute_predicate "42", :empty?
+  end
+
+  def test_refute_predicate_triggered
+    util_assert_triggered 'Expected "" to not be empty?.' do
+      @tc.refute_predicate "", :empty?
+    end
+  end
+
+  def test_refute_operator
+    @tc.refute_operator 2, :<, 1
+  end
+
+  def test_refute_operator_bad_object
+    bad = Object.new
+    def bad.==(other) true end
+
+    @tc.refute_operator true, :equal?, bad
+  end
+
+  def test_refute_operator_triggered
+    util_assert_triggered "Expected 2 to not be > 1." do
+      @tc.refute_operator 2, :>, 1
+    end
+  end
+
+  def test_refute_respond_to
+    @tc.refute_respond_to "blah", :rawr!
+  end
+
+  def test_refute_respond_to_triggered
+    util_assert_triggered 'Expected "blah" to not respond to empty?.' do
+      @tc.refute_respond_to "blah", :empty?
+    end
+  end
+
+  def test_refute_same
+    @tc.refute_same 1, 2
+  end
+
+  def test_refute_same_triggered
+    util_assert_triggered 'Expected 1 (oid=N) to not be the same as 1 (oid=N).' do
+      @tc.refute_same 1, 1
+    end
+  end
+
+  def test_skip
+    @assertion_count = 0
+
+    util_assert_triggered "haha!", MiniTest::Skip do
+      @tc.skip "haha!"
+    end
+  end
+
+  def test_test_methods_random
+    @assertion_count = 0
+
+    sample_test_case = Class.new MiniTest::Unit::TestCase do
+      def self.test_order; :random; end
+      def test_test1; assert "does not matter" end
+      def test_test2; assert "does not matter" end
+      def test_test3; assert "does not matter" end
+      @test_order = [1, 0, 2]
+      def self.rand(n) @test_order.shift; end
+    end
+
+    expected = %w(test_test2 test_test1 test_test3)
+    assert_equal expected, sample_test_case.test_methods
+  end
+
+  def test_test_methods_sorted
+    @assertion_count = 0
+
+    sample_test_case = Class.new MiniTest::Unit::TestCase do
+      def self.test_order; :sorted end
+      def test_test3; assert "does not matter" end
+      def test_test2; assert "does not matter" end
+      def test_test1; assert "does not matter" end
+    end
+
+    expected = %w(test_test1 test_test2 test_test3)
+    assert_equal expected, sample_test_case.test_methods
+  end
+
+  def assert_triggered expected, klass = MiniTest::Assertion
+    e = assert_raises klass do
+      yield
+    end
+
+    msg = e.message.sub(/(---Backtrace---).*/m, '\1')
+    msg.gsub!(/\(oid=[-0-9]+\)/, '(oid=N)')
+    msg.gsub!(/(\d\.\d{6})\d+/, '\1xxx') # normalize: ruby version, impl, platform
+
+    assert_equal expected, msg
+  end
+  alias util_assert_triggered assert_triggered
+
+  def util_msg exp, act, msg = nil
+    s = "Expected: #{exp.inspect}\n  Actual: #{act.inspect}"
+    s = "#{msg}.\n#{s}" if msg
+    s
+  end
+
+  def without_diff
+    old_diff = MiniTest::Assertions.diff
+    MiniTest::Assertions.diff = nil
+
+    yield
+  ensure
+    MiniTest::Assertions.diff = old_diff
+  end
+end
+
+class TestMiniTestGuard < MiniTest::Unit::TestCase
+  def test_mri_eh
+    assert self.class.mri? "ruby blah"
+    assert self.mri? "ruby blah"
+  end
+
+  def test_jruby_eh
+    assert self.class.jruby? "java"
+    assert self.jruby? "java"
+  end
+
+  def test_rubinius_eh
+    assert self.class.rubinius? "rbx"
+    assert self.rubinius? "rbx"
+  end
+
+  def test_windows_eh
+    assert self.class.windows? "mswin"
+    assert self.windows? "mswin"
+  end
+end
+
+class TestMiniTestUnitRecording < MetaMetaMetaTestCase
+  # do not parallelize this suite... it just can't handle it.
+
+  def assert_run_record(*expected, &block)
+    def @tu.record suite, method, assertions, time, error
+      recording[method] << error
+    end
+
+    def @tu.recording
+      @recording ||= Hash.new { |h,k| h[k] = [] }
+    end
+
+    MiniTest::Unit.runner = @tu
+
+    Class.new MiniTest::Unit::TestCase, &block
+
+    with_output do
+      @tu.run
+    end
+
+    recorded = @tu.recording.fetch("test_method").map(&:class)
+
+    assert_equal expected, recorded
+  end
+
+  def test_record_passing
+    assert_run_record NilClass do
+      def test_method
+        assert true
+      end
+    end
+  end
+
+  def test_record_failing
+    assert_run_record MiniTest::Assertion do
+      def test_method
+        assert false
+      end
+    end
+  end
+
+  def test_record_error
+    assert_run_record RuntimeError do
+      def test_method
+        raise "unhandled exception"
+      end
+    end
+  end
+
+  def test_record_error_teardown
+    assert_run_record NilClass, RuntimeError do
+      def test_method
+        assert true
+      end
+
+      def teardown
+        raise "unhandled exception"
+      end
+    end
+  end
+
+  def test_record_error_in_test_and_teardown
+    assert_run_record AnError, RuntimeError do
+      def test_method
+        raise AnError
+      end
+
+      def teardown
+        raise "unhandled exception"
+      end
+    end
+  end
+
+  def test_record_skip
+    assert_run_record MiniTest::Skip do
+      def test_method
+        skip "not yet"
+      end
+    end
+  end
+end
diff --git a/tool/test/testunit/test4test_hideskip.rb b/tool/test/testunit/test4test_hideskip.rb
new file mode 100644
index 0000000000..410bffc13c
--- /dev/null
+++ b/tool/test/testunit/test4test_hideskip.rb
@@ -0,0 +1,10 @@
+# frozen_string_literal: false
+$LOAD_PATH.unshift "#{File.dirname(__FILE__)}/../../lib"
+
+require 'test/unit'
+
+class TestForTestHideSkip < Test::Unit::TestCase
+  def test_skip
+    skip "do nothing"
+  end
+end
diff --git a/tool/test/testunit/test4test_redefinition.rb b/tool/test/testunit/test4test_redefinition.rb
new file mode 100644
index 0000000000..ad3c5e7113
--- /dev/null
+++ b/tool/test/testunit/test4test_redefinition.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: false
+$LOAD_PATH.unshift "#{File.dirname(__FILE__)}/../../lib"
+
+require 'test/unit'
+
+class TestForTestRedefinition < Test::Unit::TestCase
+  def test_redefinition
+    skip "do nothing (1)"
+  end
+
+  def test_redefinition
+    skip "do nothing (2)"
+  end
+end
diff --git a/tool/test/testunit/test4test_sorting.rb b/tool/test/testunit/test4test_sorting.rb
new file mode 100644
index 0000000000..698c875b79
--- /dev/null
+++ b/tool/test/testunit/test4test_sorting.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: false
+$LOAD_PATH.unshift "#{File.dirname(__FILE__)}/../../lib"
+
+require 'test/unit'
+
+class TestForTestHideSkip < Test::Unit::TestCase
+  def test_c
+    skip "do nothing"
+  end
+
+  def test_b
+    assert_equal true, false
+  end
+
+  def test_a
+    raise
+  end
+end
diff --git a/tool/test/testunit/test_assertion.rb b/tool/test/testunit/test_assertion.rb
new file mode 100644
index 0000000000..0c7c4882b8
--- /dev/null
+++ b/tool/test/testunit/test_assertion.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: false
+require 'test/unit'
+class TestAssertion < Test::Unit::TestCase
+  def test_wrong_assertion
+    error, line = assert_raise(ArgumentError) {assert(true, true)}, __LINE__
+    assert_match(/assertion message must be String or Proc, but TrueClass was given/, error.message)
+    assert_match(/\A#{Regexp.quote(__FILE__)}:#{line}:/, error.backtrace[0])
+  end
+
+  def test_timeout_separately
+    assert_raise(Timeout::Error) do
+      assert_separately([], <<~"end;", timeout: 0.1)
+        sleep
+      end;
+    end
+  end
+
+  def return_in_assert_raise
+    assert_raise(RuntimeError) do
+      return
+    end
+  end
+
+  def test_assert_raise
+    assert_raise(MiniTest::Assertion) do
+      return_in_assert_raise
+    end
+  end
+end
diff --git a/tool/test/testunit/test_hideskip.rb b/tool/test/testunit/test_hideskip.rb
new file mode 100644
index 0000000000..0188316a2c
--- /dev/null
+++ b/tool/test/testunit/test_hideskip.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: false
+require 'test/unit'
+
+class TestHideSkip < Test::Unit::TestCase
+  def test_hideskip
+    assert_not_match(/^ *1\) Skipped/, hideskip)
+    assert_match(/^ *1\) Skipped/, hideskip("--show-skip"))
+    output = hideskip("--hide-skip")
+    output.gsub!(/Successful MJIT finish\n/, '') if RubyVM::MJIT.enabled?
+    assert_match(/assertions\/s.\n+1 tests, 0 assertions, 0 failures, 0 errors, 1 skips/, output)
+  end
+
+  private
+
+  def hideskip(*args)
+    IO.popen([*@options[:ruby], "#{File.dirname(__FILE__)}/test4test_hideskip.rb",
+                       "--verbose", *args], err: [:child, :out]) {|f|
+      f.read
+    }
+  end
+end
diff --git a/tool/test/testunit/test_parallel.rb b/tool/test/testunit/test_parallel.rb
new file mode 100644
index 0000000000..2cb85ad3e0
--- /dev/null
+++ b/tool/test/testunit/test_parallel.rb
@@ -0,0 +1,203 @@
+# frozen_string_literal: false
+require 'test/unit'
+require 'timeout'
+
+module TestParallel
+  PARALLEL_RB = "#{File.dirname(__FILE__)}/../../lib/test/unit/parallel.rb"
+  TESTS = "#{File.dirname(__FILE__)}/tests_for_parallel"
+  # use large timeout for --jit-wait
+  TIMEOUT = EnvUtil.apply_timeout_scale(RubyVM::MJIT.enabled? ? 100 : 30)
+
+  class TestParallelWorker < Test::Unit::TestCase
+    def setup
+      i, @worker_in = IO.pipe
+      @worker_out, o = IO.pipe
+      @worker_pid = spawn(*@options[:ruby], PARALLEL_RB,
+                          "--ruby", @options[:ruby].join(" "),
+                          "-j", "t1", "-v", out: o, in: i)
+      [i,o].each(&:close)
+    end
+
+    def teardown
+      if @worker_pid && @worker_in
+        begin
+          begin
+            @worker_in.puts "quit"
+          rescue IOError, Errno::EPIPE
+          end
+          Timeout.timeout(2) do
+            Process.waitpid(@worker_pid)
+          end
+        rescue Timeout::Error
+          begin
+            Process.kill(:KILL, @worker_pid)
+          rescue Errno::ESRCH
+          end
+        end
+      end
+    ensure
+      begin
+        @worker_in.close
+        @worker_out.close
+      rescue Errno::EPIPE
+        # may already broken and rescue'ed in above code
+      end
+    end
+
+    def test_run
+      Timeout.timeout(TIMEOUT) do
+        assert_match(/^ready/,@worker_out.gets)
+        @worker_in.puts "run #{TESTS}/ptest_first.rb test"
+        assert_match(/^okay/,@worker_out.gets)
+        assert_match(/^record/,@worker_out.gets)
+        assert_match(/^p/,@worker_out.gets)
+        assert_match(/^done/,@worker_out.gets)
+        assert_match(/^ready/,@worker_out.gets)
+      end
+    end
+
+    def test_run_multiple_testcase_in_one_file
+      Timeout.timeout(TIMEOUT) do
+        assert_match(/^ready/,@worker_out.gets)
+        @worker_in.puts "run #{TESTS}/ptest_second.rb test"
+        assert_match(/^okay/,@worker_out.gets)
+        assert_match(/^record/,@worker_out.gets)
+        assert_match(/^p/,@worker_out.gets)
+        assert_match(/^done/,@worker_out.gets)
+        assert_match(/^record/,@worker_out.gets)
+        assert_match(/^p/,@worker_out.gets)
+        assert_match(/^done/,@worker_out.gets)
+        assert_match(/^ready/,@worker_out.gets)
+      end
+    end
+
+    def test_accept_run_command_multiple_times
+      Timeout.timeout(TIMEOUT) do
+        assert_match(/^ready/,@worker_out.gets)
+        @worker_in.puts "run #{TESTS}/ptest_first.rb test"
+        assert_match(/^okay/,@worker_out.gets)
+        assert_match(/^record/,@worker_out.gets)
+        assert_match(/^p/,@worker_out.gets)
+        assert_match(/^done/,@worker_out.gets)
+        assert_match(/^ready/,@worker_out.gets)
+        @worker_in.puts "run #{TESTS}/ptest_second.rb test"
+        assert_match(/^okay/,@worker_out.gets)
+        assert_match(/^record/,@worker_out.gets)
+        assert_match(/^p/,@worker_out.gets)
+        assert_match(/^done/,@worker_out.gets)
+        assert_match(/^record/,@worker_out.gets)
+        assert_match(/^p/,@worker_out.gets)
+        assert_match(/^done/,@worker_out.gets)
+        assert_match(/^ready/,@worker_out.gets)
+      end
+    end
+
+    def test_p
+      Timeout.timeout(TIMEOUT) do
+        @worker_in.puts "run #{TESTS}/ptest_first.rb test"
+        while buf = @worker_out.gets
+          break if /^p (.+?)$/ =~ buf
+        end
+        assert_match(/TestA#test_nothing_test = \d+\.\d+ s = \.\n/, $1.chomp.unpack("m")[0])
+      end
+    end
+
+    def test_done
+      Timeout.timeout(TIMEOUT) do
+        @worker_in.puts "run #{TESTS}/ptest_forth.rb test"
+        while buf = @worker_out.gets
+          break if /^done (.+?)$/ =~ buf
+        end
+
+        result = Marshal.load($1.chomp.unpack("m")[0])
+
+        assert_equal(5, result[0])
+        assert_equal(2, result[1])
+        assert_kind_of(Array,result[2])
+        assert_kind_of(Array,result[3])
+        assert_kind_of(Array,result[4])
+        assert_kind_of(Array,result[2][1])
+        assert_kind_of(MiniTest::Assertion,result[2][0][2])
+        assert_kind_of(MiniTest::Skip,result[2][1][2])
+        assert_kind_of(MiniTest::Skip,result[2][2][2])
+        assert_kind_of(Exception, result[2][3][2])
+        assert_equal(result[5], "TestE")
+      end
+    end
+
+    def test_quit
+      Timeout.timeout(TIMEOUT) do
+        @worker_in.puts "quit"
+        assert_match(/^bye$/m,@worker_out.read)
+      end
+    end
+  end
+
+  class TestParallel < Test::Unit::TestCase
+    def spawn_runner(*opt_args)
+      @test_out, o = IO.pipe
+      @test_pid = spawn(*@options[:ruby], TESTS+"/runner.rb",
+                        "--ruby", @options[:ruby].join(" "),
+                        "-j","t1",*opt_args, out: o, err: o)
+      o.close
+    end
+
+    def teardown
+      begin
+        if @test_pid
+          Timeout.timeout(2) do
+            Process.waitpid(@test_pid)
+          end
+        end
+      rescue Timeout::Error
+        Process.kill(:KILL, @test_pid) if @test_pid
+      ensure
+        @test_out&.close
+      end
+    end
+
+    def test_ignore_jzero
+      @test_out, o = IO.pipe
+      @test_pid = spawn(*@options[:ruby], TESTS+"/runner.rb",
+                        "--ruby", @options[:ruby].join(" "),
+                        "-j","0", out: File::NULL, err: o)
+      o.close
+      Timeout.timeout(TIMEOUT) {
+        assert_match(/Error: parameter of -j option should be greater than 0/,@test_out.read)
+      }
+    end
+
+    def test_should_run_all_without_any_leaks
+      spawn_runner
+      buf = Timeout.timeout(TIMEOUT) {@test_out.read}
+      assert_match(/^9 tests/,buf)
+    end
+
+    def test_should_retry_failed_on_workers
+      spawn_runner
+      buf = Timeout.timeout(TIMEOUT) {@test_out.read}
+      assert_match(/^Retrying\.+$/,buf)
+    end
+
+    def test_no_retry_option
+      spawn_runner "--no-retry"
+      buf = Timeout.timeout(TIMEOUT) {@test_out.read}
+      refute_match(/^Retrying\.+$/,buf)
+      assert_match(/^ +\d+\) Failure:\nTestD#test_fail_at_worker/,buf)
+    end
+
+    def test_jobs_status
+      spawn_runner "--jobs-status"
+      buf = Timeout.timeout(TIMEOUT) {@test_out.read}
+      assert_match(/\d+=ptest_(first|second|third|forth) */,buf)
+    end
+
+    def test_separate
+      # this test depends to --jobs-status
+      spawn_runner "--jobs-status", "--separate"
+      buf = Timeout.timeout(TIMEOUT) {@test_out.read}
+      assert(buf.scan(/^\[\s*\d+\/\d+\]\s*(\d+?)=/).flatten.uniq.size > 1,
+             message("retried tests should run in different processes") {buf})
+    end
+  end
+end
diff --git a/tool/test/testunit/test_redefinition.rb b/tool/test/testunit/test_redefinition.rb
new file mode 100644
index 0000000000..9129e55489
--- /dev/null
+++ b/tool/test/testunit/test_redefinition.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: false
+require 'test/unit'
+
+class TestRedefinition < Test::Unit::TestCase
+  def test_redefinition
+    assert_match(/^test\/unit warning: method TestForTestRedefinition#test_redefinition is redefined$/,
+                 redefinition)
+  end
+
+  def redefinition(*args)
+    IO.popen([*@options[:ruby], "#{File.dirname(__FILE__)}/test4test_redefinition.rb", *args],
+                      err: [:child, :out]) {|f|
+      f.read
+    }
+  end
+end
diff --git a/tool/test/testunit/test_sorting.rb b/tool/test/testunit/test_sorting.rb
new file mode 100644
index 0000000000..f9de3ec154
--- /dev/null
+++ b/tool/test/testunit/test_sorting.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: false
+require 'test/unit'
+
+class TestTestUnitSorting < Test::Unit::TestCase
+  def test_sorting
+    result = sorting("--show-skip")
+    assert_match(/^  1\) Skipped:/, result)
+    assert_match(/^  2\) Failure:/, result)
+    assert_match(/^  3\) Error:/,   result)
+  end
+
+  def sorting(*args)
+    IO.popen([*@options[:ruby], "#{File.dirname(__FILE__)}/test4test_sorting.rb",
+              "--verbose", *args], err: [:child, :out]) {|f|
+      f.read
+    }
+  end
+end
diff --git a/tool/test/testunit/tests_for_parallel/ptest_first.rb b/tool/test/testunit/tests_for_parallel/ptest_first.rb
new file mode 100644
index 0000000000..f8687335b5
--- /dev/null
+++ b/tool/test/testunit/tests_for_parallel/ptest_first.rb
@@ -0,0 +1,8 @@
+# frozen_string_literal: false
+require 'test/unit'
+
+class TestA < Test::Unit::TestCase
+  def test_nothing_test
+  end
+end
+
diff --git a/tool/test/testunit/tests_for_parallel/ptest_forth.rb b/tool/test/testunit/tests_for_parallel/ptest_forth.rb
new file mode 100644
index 0000000000..8831676e19
--- /dev/null
+++ b/tool/test/testunit/tests_for_parallel/ptest_forth.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: false
+require 'test/unit'
+
+class TestE < Test::Unit::TestCase
+  class UnknownError < RuntimeError; end
+
+  def test_not_fail
+    assert_equal(1,1)
+  end
+
+  def test_always_skip
+    skip "always"
+  end
+
+  def test_always_fail
+    assert_equal(0,1)
+  end
+
+  def test_skip_after_unknown_error
+    begin
+      raise UnknownError, "unknown error"
+    rescue
+      skip "after raise"
+    end
+  end
+
+  def test_unknown_error
+    raise UnknownError, "unknown error"
+  end
+end
diff --git a/tool/test/testunit/tests_for_parallel/ptest_second.rb b/tool/test/testunit/tests_for_parallel/ptest_second.rb
new file mode 100644
index 0000000000..a793c17eb3
--- /dev/null
+++ b/tool/test/testunit/tests_for_parallel/ptest_second.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: false
+require 'test/unit'
+
+class TestB < Test::Unit::TestCase
+  def test_nothing
+  end
+end
+
+class TestC < Test::Unit::TestCase
+  def test_nothing
+  end
+end
diff --git a/tool/test/testunit/tests_for_parallel/ptest_third.rb b/tool/test/testunit/tests_for_parallel/ptest_third.rb
new file mode 100644
index 0000000000..3f448ecfc1
--- /dev/null
+++ b/tool/test/testunit/tests_for_parallel/ptest_third.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: false
+require 'test/unit'
+
+class TestD < Test::Unit::TestCase
+  def test_fail_at_worker
+    #if /test\/unit\/parallel\.rb/ =~ $0
+    if on_parallel_worker?
+      assert_equal(0,1)
+    end
+  end
+end
diff --git a/tool/test/testunit/tests_for_parallel/runner.rb b/tool/test/testunit/tests_for_parallel/runner.rb
new file mode 100644
index 0000000000..02699e271e
--- /dev/null
+++ b/tool/test/testunit/tests_for_parallel/runner.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: false
+require 'rbconfig'
+
+$LOAD_PATH.unshift "#{File.dirname(__FILE__)}/../../../lib"
+
+require 'test/unit'
+
+src_testdir = File.dirname(File.expand_path(__FILE__))
+
+class Test::Unit::Runner
+  @@testfile_prefix = "ptest"
+end
+
+exit Test::Unit::AutoRunner.run(true, src_testdir)