import subprocess
import unittest


class TestHello(unittest.TestCase):
    def test_hello_output(self):
        """Test that hello.py prints 'Hello, World!' to stdout."""
        result = subprocess.run(
            ["python3", "hello.py"],
            capture_output=True,
            text=True,
            cwd="/workspace"
        )
        self.assertEqual(result.returncode, 0)
        self.assertIn("Hello, World!", result.stdout)

    def test_hello_no_stderr(self):
        """Test that hello.py produces no stderr output."""
        result = subprocess.run(
            ["python3", "hello.py"],
            capture_output=True,
            text=True,
            cwd="/workspace"
        )
        self.assertEqual(result.stderr, "")


if __name__ == "__main__":
    unittest.main()