"""Tests for hello.py module using pytest."""

import subprocess
from pathlib import Path

# Module-level constants to avoid duplication across test functions
HELLO_SCRIPT = Path(__file__).parent.parent / "hello.py"
WORKING_DIR = Path(__file__).parent.parent


def run_hello():
    """Run hello.py and return the subprocess result."""
    return subprocess.run(
        ["python3", str(HELLO_SCRIPT)],
        capture_output=True,
        text=True,
        cwd=WORKING_DIR,
    )


class TestHelloOutput:
    """Tests for hello.py output behavior."""

    def test_hello_prints_expected_message(self):
        """Test that hello.py prints 'Hello, World!' to stdout."""
        result = run_hello()
        assert "Hello, World!" in result.stdout

    def test_hello_exact_output(self):
        """Test that hello.py output matches exactly (with newline)."""
        result = run_hello()
        assert result.stdout.strip() == "Hello, World!"

    def test_hello_exit_code_zero(self):
        """Test that hello.py exits with code 0."""
        result = run_hello()
        assert result.returncode == 0

    def test_hello_no_stderr(self):
        """Test that hello.py produces no stderr output."""
        result = run_hello()
        assert result.stderr == ""

    def test_hello_stdout_not_empty(self):
        """Test that hello.py produces non-empty stdout."""
        result = run_hello()
        assert len(result.stdout) > 0


class TestHelloFile:
    """Tests for hello.py file existence and content."""

    def test_hello_file_exists(self):
        """Test that hello.py file exists."""
        assert HELLO_SCRIPT.exists()

    def test_hello_file_is_python(self):
        """Test that hello.py has .py extension."""
        assert HELLO_SCRIPT.suffix == ".py"

    def test_hello_file_contains_print(self):
        """Test that hello.py contains a print statement."""
        content = HELLO_SCRIPT.read_text()
        assert "print" in content

    def test_hello_file_contains_hello_world(self):
        """Test that hello.py contains 'Hello, World!' string."""
        content = HELLO_SCRIPT.read_text()
        assert "Hello, World!" in content