"""Tests for pythonnative._ios_log (iOS stdout/stderr redirection).

These tests exercise the module's behavior directly without requiring

an actual iOS runtime: ``_StderrStream`` writes via ``os.write(2, ...)``,

and ``install()`` is idempotent and swaps the ``sys`` streams in place.

"""

import io

import os

import sys

from typing import Generator, List, Tuple

import pytest

from pythonnative import _ios_log

from pythonnative._ios_log import _StderrStream, install

class TestStderrStream:

def test_write_sends_utf8_bytes_to_fd_2(self, monkeypatch: pytest.MonkeyPatch) -> None:

captured: List[Tuple[int, bytes]] = []

def fake_write(fd: int, data: bytes) -> int:

captured.append((fd, data))

return len(data)

monkeypatch.setattr(os, "write", fake_write)

stream = _StderrStream()

written = stream.write("hello\n")

assert captured == [(2, b"hello\n")]

assert written == len(b"hello\n")

def test_write_handles_non_ascii(self, monkeypatch: pytest.MonkeyPatch) -> None:

captured: List[bytes] = []

def fake_write(fd: int, data: bytes) -> int:

captured.append(data)

return len(data)

monkeypatch.setattr(os, "write", fake_write)

_StderrStream().write("héllo ✓\n")

assert captured == ["héllo ✓\n".encode("utf-8")]

def test_write_empty_string_is_no_op(self, monkeypatch: pytest.MonkeyPatch) -> None:

calls: List[Tuple[int, bytes]] = []

def fake_write(fd: int, data: bytes) -> int:

calls.append((fd, data))

return len(data)

monkeypatch.setattr(os, "write", fake_write)

assert _StderrStream().write("") == 0

assert calls == []

def test_write_swallows_oserror(self, monkeypatch: pytest.MonkeyPatch) -> None:

def boom(fd: int, data: bytes) -> int:

raise OSError("nope")

monkeypatch.setattr(os, "write", boom)

assert _StderrStream().write("x") == 0

def test_writelines_iterates(self, monkeypatch: pytest.MonkeyPatch) -> None:

captured: List[bytes] = []

def fake_write(fd: int, data: bytes) -> int:

captured.append(data)

return len(data)

monkeypatch.setattr(os, "write", fake_write)

_StderrStream().writelines(["a\n", "b\n", "c\n"])

assert captured == [b"a\n", b"b\n", b"c\n"]

def test_stream_metadata(self) -> None:

stream = _StderrStream()

assert stream.encoding == "utf-8"

assert stream.errors == "replace"

assert stream.fileno() == 2

assert stream.closed is False

# flush() and close() are deliberate no-ops; just exercise them.

stream.flush()

stream.close()

def test_isatty_reflects_fd_2(self, monkeypatch: pytest.MonkeyPatch) -> None:

monkeypatch.setattr(os, "isatty", lambda fd: fd == 2)

assert _StderrStream().isatty() is True

def raiser(fd: int) -> bool:

raise OSError("bad fd")

monkeypatch.setattr(os, "isatty", raiser)

assert _StderrStream().isatty() is False

class TestInstall:

@pytest.fixture(autouse=True)

def _reset_install_flag(self) -> Generator[None, None, None]:

"""Ensure each test starts with a fresh, un-installed state."""

original_stdout = sys.stdout

original_stderr = sys.stderr

original_installed = _ios_log._installed

_ios_log._installed = False

try:

yield

finally:

sys.stdout = original_stdout

sys.stderr = original_stderr

_ios_log._installed = original_installed

def test_install_replaces_streams(self) -> None:

assert not isinstance(sys.stdout, _StderrStream)

assert not isinstance(sys.stderr, _StderrStream)

install()

assert isinstance(sys.stdout, _StderrStream)

assert isinstance(sys.stderr, _StderrStream)

def test_install_is_idempotent(self) -> None:

install()

first_stdout = sys.stdout

first_stderr = sys.stderr

install()

install()

# Second+ install() calls must be no-ops — the same objects remain.

assert sys.stdout is first_stdout

assert sys.stderr is first_stderr

def test_install_does_not_raise_when_streams_missing(self, monkeypatch: pytest.MonkeyPatch) -> None:

# Replace stdout/stderr with something odd before install to confirm

# install() doesn't care about the prior stream.

monkeypatch.setattr(sys, "stdout", io.StringIO())

monkeypatch.setattr(sys, "stderr", io.StringIO())

install()

assert isinstance(sys.stdout, _StderrStream)

assert isinstance(sys.stderr, _StderrStream)