1 files changed, 25 insertions, 0 deletions
diff --git a/tool/test/testunit/test_assertion.rb b/tool/test/testunit/test_assertion.rb
index b0c2267b31..d9bdc8f3c5 100644
--- a/tool/test/testunit/test_assertion.rb
+++ b/tool/test/testunit/test_assertion.rb
@@ -8,6 +8,8 @@ class TestAssertion < Test::Unit::TestCase
   end
 
   def test_timeout_separately
+    pend "hang-up" if /mswin|mingw/ =~ RUBY_PLATFORM
+
     assert_raise(Timeout::Error) do
       assert_separately([], <<~"end;", timeout: 0.1)
         sleep
@@ -15,6 +17,29 @@ class TestAssertion < Test::Unit::TestCase
     end
   end
 
+  def test_assertion_count_separately
+    beginning = self._assertions
+
+    assert_separately([], "")
+    assertions_at_nothing = self._assertions - beginning
+
+    prev_assertions = self._assertions + assertions_at_nothing
+    assert_separately([], "assert true")
+    assert_equal(1, self._assertions - prev_assertions)
+
+    omit unless Process.respond_to?(:fork)
+    prev_assertions = self._assertions + assertions_at_nothing
+    assert_separately([], "Process.fork {assert true}; assert true")
+    assert_equal(2, self._assertions - prev_assertions)
+
+    prev_assertions = self._assertions + assertions_at_nothing
+    # TODO: assertions before `fork` are counted twice; it is possible
+    # to reset `_assertions` at `Process._fork`, but the hook can
+    # interfere in other tests.
+    assert_separately([], "assert true; Process.fork {assert true}")
+    assert_equal(3, self._assertions - prev_assertions)
+  end
+
   def return_in_assert_raise
     assert_raise(RuntimeError) do
       return