import sys
import pytest

import cipy._io


def test_capture_cout() -> None:
    with cipy._io.capture_stdout() as out:
        print("Hello, World")
        sys.stdout.flush()
        assert out.getvalue() == "Hello, World\n"


def test_capture_cerr() -> None:
    with cipy._io.capture_stderr() as out:
        print("Hello, World", file=sys.stderr)
        sys.stderr.flush()
        assert out.getvalue() == "Hello, World\n"


def test_capture_expires_scope() -> None:
    with cipy._io.capture_stdout() as out:
        pass
    with pytest.raises(ValueError):
        out.read()