import os
import pty
import subprocess
import time


def test_ssh_space_backspace(wermit_path):
    """
    Test that typing 'ssh ' and then backspacing over the space at the command
    prompt does not emit an error ('?Invalid argument').
    """
    master, slave = pty.openpty()
    proc = subprocess.Popen(
        [str(wermit_path), "-H", "-Y", "-Q"],
        stdin=slave,
        stdout=slave,
        stderr=slave,
        close_fds=True,
    )
    os.close(slave)

    try:
        time.sleep(0.3)
        os.read(master, 2048)

        # Type 'ssh '
        os.write(master, b"ssh ")
        time.sleep(0.2)
        out_space = os.read(master, 2048)

        # Backspace over space
        os.write(master, b"\x7f")
        time.sleep(0.2)
        out_bs = os.read(master, 2048)

        assert b"Invalid argument" not in out_space
        assert b"Invalid argument" not in out_bs
        assert out_bs.startswith(b"\x08 \x08")
    finally:
        proc.kill()
        proc.wait()
        os.close(master)