"""
Shared test helpers for the Outline Sync Web UI test suite.
Import directly: from tests.helpers import make_mock_process
"""

from unittest.mock import AsyncMock, MagicMock


class _AsyncLineIter:
    """Proper async iterator for mocking asyncio subprocess stdout."""

    def __init__(self, lines: list[str]):
        self._iter = iter(lines)

    def __aiter__(self):
        return self

    async def __anext__(self) -> bytes:
        try:
            return (next(self._iter) + "\n").encode()
        except StopIteration:
            raise StopAsyncIteration


def make_mock_process(stdout_lines: list[str], returncode: int = 0) -> MagicMock:
    """
    Build a mock asyncio subprocess whose stdout is a proper async iterable.

    Usage in tests:
        with patch("webui.spawn_sync_subprocess") as mock_spawn:
            mock_spawn.return_value = make_mock_process(["Done."])
    """
    proc = MagicMock()
    proc.returncode = returncode
    proc.stdout = _AsyncLineIter(stdout_lines)
    proc.wait = AsyncMock(return_value=returncode)
    return proc