1 files changed, 40 insertions, 2 deletions
diff --git a/test/fiber/test_process.rb b/test/fiber/test_process.rb
index c6583cac9b..a09b070c0a 100644
--- a/test/fiber/test_process.rb
+++ b/test/fiber/test_process.rb
@@ -3,13 +3,15 @@ require 'test/unit'
 require_relative 'scheduler'
 
 class TestFiberProcess < Test::Unit::TestCase
+  TRUE_CMD = RUBY_PLATFORM =~ /mswin|mingw/ ? "exit 0" : "true"
+
   def test_process_wait
     Thread.new do
       scheduler = Scheduler.new
       Fiber.set_scheduler scheduler
 
       Fiber.schedule do
-        pid = Process.spawn("true")
+        pid = Process.spawn(TRUE_CMD)
         Process.wait(pid)
 
         # TODO test that scheduler was invoked.
@@ -25,7 +27,7 @@ class TestFiberProcess < Test::Unit::TestCase
       Fiber.set_scheduler scheduler
 
       Fiber.schedule do
-        system("true")
+        system(TRUE_CMD)
 
         # TODO test that scheduler was invoked (currently it's not).
 
@@ -33,4 +35,40 @@ class TestFiberProcess < Test::Unit::TestCase
       end
     end.join
   end
+
+  def test_system_faulty_process_wait
+    Thread.new do
+      scheduler = Scheduler.new
+
+      def scheduler.process_wait(pid, flags)
+        Fiber.blocking{Process.wait(pid, flags)}
+
+        # Don't return `Process::Status` instance.
+        return false
+      end
+
+      Fiber.set_scheduler scheduler
+
+      Fiber.schedule do
+        assert_raise TypeError do
+          system(TRUE_CMD)
+        end
+      end
+    end.join
+  end
+
+  def test_fork
+    omit 'fork not supported' unless Process.respond_to?(:fork)
+    Thread.new do
+      scheduler = Scheduler.new
+      Fiber.set_scheduler scheduler
+
+      Fiber.schedule do
+        pid = Process.fork {}
+        Process.wait(pid)
+
+        assert_predicate $?, :success?
+      end
+    end.join
+  end
 end