testsAndMisc/python_pkg/brother_printer/tests/test_usb_query.py
Krzysztof kuhy Rudnicki 143dd9ff3d Split brother_printer CUPS fallback query out of cups_service
cups_service.py 406 -> 234. The IPP attribute queries, the CUPS
status-code mapping, find_cups_printer_name and query_usb_via_cups move
to _cups_fallback.py; cups_service keeps service control and raw USB
port status.

The seam is not the section header: test_cups_service_part2.py imports
_get_cups_economode and find_cups_printer_name together and patches
shutil once, so those two had to travel as a pair. test_cups_service.py,
the largest module, needs no edit.

usb_query.py reaches the fallback through a late import_module, so both
that string and the absolute patch target in test_usb_query.py moved
with it. Pass count is 402 before and after.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011w2Pj4Ek3ZNMQVYcFHgXDY
2026-08-16 17:02:42 +02:00

329 lines
12 KiB
Python

"""Tests for brother_printer.usb_query module."""
from __future__ import annotations
import errno
import os
from unittest.mock import MagicMock, patch
from python_pkg.brother_printer.data_classes import USBResult
from python_pkg.brother_printer.usb_query import (
_init_usb_result,
_parse_pagecount,
_parse_status,
_parse_variables,
_retry_pjl_query,
_run_pjl_queries,
find_brother_usb,
find_usb_printer_dev,
query_usb_pjl,
)
MOD = "python_pkg.brother_printer.usb_query"
class TestFindBrotherUsb:
@patch(f"{MOD}.shutil.which", return_value=None)
def test_no_lsusb(self, m: MagicMock) -> None:
assert find_brother_usb() == ""
@patch("python_pkg.brother_printer._query.subprocess.run")
@patch(f"{MOD}.shutil.which", return_value="/usr/bin/lsusb")
def test_found(self, w: MagicMock, mock_run: MagicMock) -> None:
mock_run.return_value = MagicMock(
stdout="Bus 001 Device 005: ID 04f9:0042 Brother Industries\n",
)
result = find_brother_usb()
assert "Brother" in result
@patch("python_pkg.brother_printer._query.subprocess.run")
@patch(f"{MOD}.shutil.which", return_value="/usr/bin/lsusb")
def test_not_found(self, w: MagicMock, mock_run: MagicMock) -> None:
mock_run.return_value = MagicMock(stdout="Bus 001 Device 001: Hub\n")
assert find_brother_usb() == ""
@patch("python_pkg.brother_printer._query.subprocess.run")
@patch(f"{MOD}.shutil.which", return_value="/usr/bin/lsusb")
def test_line_with_colon_sep(self, w: MagicMock, mock_run: MagicMock) -> None:
"""Line contains 04f9: but no ': ' separator → returns full line."""
mock_run.return_value = MagicMock(stdout="ID 04f9:0042\n")
result = find_brother_usb()
assert result == "ID 04f9:0042"
@patch("python_pkg.brother_printer._query.subprocess.run")
@patch(f"{MOD}.shutil.which", return_value="/usr/bin/lsusb")
def test_no_match(self, w: MagicMock, mock_run: MagicMock) -> None:
"""Line without 04f9: vendor id is ignored."""
mock_run.return_value = MagicMock(stdout="04f9 brother no colon\n")
assert find_brother_usb() == ""
@patch("python_pkg.brother_printer._query.subprocess.run")
@patch(f"{MOD}.shutil.which", return_value="/usr/bin/lsusb")
def test_timeout(self, w: MagicMock, mock_run: MagicMock) -> None:
import subprocess
mock_run.side_effect = subprocess.TimeoutExpired("lsusb", 5)
assert find_brother_usb() == ""
@patch("python_pkg.brother_printer._query.subprocess.run")
@patch(f"{MOD}.shutil.which", return_value="/usr/bin/lsusb")
def test_oserror(self, w: MagicMock, mock_run: MagicMock) -> None:
mock_run.side_effect = OSError("fail")
assert find_brother_usb() == ""
class TestFindUsbPrinterDev:
@patch(f"{MOD}.Path")
def test_found(self, mock_path_cls: MagicMock) -> None:
mock_path_cls.return_value = mock_path_cls
mock_path_cls.__truediv__ = lambda _self, _x: mock_path_cls
lp0 = MagicMock()
lp0.__str__ = lambda _s: "/dev/usb/lp0"
lp0.__lt__ = lambda s, o: str(s) < str(o)
mock_usb = MagicMock()
mock_usb.glob.return_value = [lp0]
mock_path_cls.side_effect = None
with patch(f"{MOD}.Path", return_value=mock_usb):
result = find_usb_printer_dev()
assert result == "/dev/usb/lp0"
@patch(f"{MOD}.Path")
def test_not_found(self, mock_path_cls: MagicMock) -> None:
mock_usb = MagicMock()
mock_usb.glob.return_value = []
mock_path_cls.return_value = mock_usb
result = find_usb_printer_dev()
assert result is None
class TestParseStatus:
def test_found(self) -> None:
result = USBResult()
resp = 'CODE=10001\nDISPLAY= "Ready" \nONLINE=TRUE\n'
assert _parse_status(resp, result) is True
assert result.status_code == "10001"
assert result.display == "Ready"
assert result.online == "TRUE"
def test_not_found(self) -> None:
result = USBResult()
assert _parse_status("nothing here\n", result) is False
def test_partial(self) -> None:
result = USBResult()
resp = "DISPLAY=Hello\n"
assert _parse_status(resp, result) is False
assert result.display == "Hello"
class TestParseVariables:
def test_found(self) -> None:
result = USBResult()
resp = "ECONOMODE=ON extra\n"
assert _parse_variables(resp, result) is True
assert result.economode == "ON"
def test_not_found(self) -> None:
result = USBResult()
assert _parse_variables("nothing\n", result) is False
class TestRetryPjlQuery:
@patch(f"{MOD}.time.sleep")
@patch(f"{MOD}._drain_buffer")
@patch(f"{MOD}.pjl_query")
def test_success_first_attempt(
self,
mock_pjl: MagicMock,
d: MagicMock,
s: MagicMock,
) -> None:
result = USBResult()
mock_pjl.return_value = "CODE=10001\n"
_retry_pjl_query(42, "@PJL INFO STATUS", _parse_status, result, 2)
assert result.status_code == "10001"
assert mock_pjl.call_count == 1
@patch(f"{MOD}.time.sleep")
@patch(f"{MOD}._drain_buffer")
@patch(f"{MOD}.pjl_query")
def test_retry_then_success(
self,
mock_pjl: MagicMock,
d: MagicMock,
s: MagicMock,
) -> None:
result = USBResult()
mock_pjl.side_effect = ["garbage\n", "CODE=10001\n"]
_retry_pjl_query(42, "@PJL INFO STATUS", _parse_status, result, 2)
assert result.status_code == "10001"
assert mock_pjl.call_count == 2
@patch(f"{MOD}.time.sleep")
@patch(f"{MOD}._drain_buffer")
@patch(f"{MOD}.pjl_query")
def test_all_retries_fail(
self,
mock_pjl: MagicMock,
d: MagicMock,
s: MagicMock,
) -> None:
result = USBResult()
mock_pjl.return_value = "garbage\n"
_retry_pjl_query(42, "@PJL INFO STATUS", _parse_status, result, 2)
assert result.status_code == ""
assert mock_pjl.call_count == 3
class TestRunPjlQueries:
@patch(f"{MOD}._retry_pjl_query")
@patch(f"{MOD}.time.sleep")
@patch(f"{MOD}._drain_buffer")
@patch(f"{MOD}._write_with_deadline")
def test_runs_status_pagecount_and_variables(
self,
mock_write: MagicMock,
d: MagicMock,
s: MagicMock,
mock_retry: MagicMock,
) -> None:
result = USBResult()
_run_pjl_queries(42, result, 2)
assert mock_retry.call_count == 3
queried = [call.args[1] for call in mock_retry.call_args_list]
assert "@PJL INFO PAGECOUNT" in queried
class TestParsePagecount:
def test_found(self) -> None:
result = USBResult()
assert _parse_pagecount("PAGECOUNT=2014\n", result) is True
assert result.page_count == "2014"
def test_not_found(self) -> None:
result = USBResult()
assert _parse_pagecount("nothing\n", result) is False
assert result.page_count == ""
def test_non_numeric_rejected(self) -> None:
"""A garbled reply must not become a page count."""
result = USBResult()
assert _parse_pagecount("PAGECOUNT=???\n", result) is False
assert result.page_count == ""
class TestInitUsbResult:
@patch(f"{MOD}.printer_info_from_cups")
def test_from_cups(self, mock_cups: MagicMock) -> None:
mock_cups.return_value = {"product": "HL-1110", "serial": "SN1"}
result = _init_usb_result("/dev/usb/lp0")
assert result.device == "/dev/usb/lp0"
assert result.product == "HL-1110"
assert result.serial == "SN1"
@patch(f"{MOD}.printer_info_from_cups")
def test_no_product(self, mock_cups: MagicMock) -> None:
mock_cups.return_value = {"product": "", "serial": ""}
result = _init_usb_result("/dev/usb/lp0")
assert result.product == "Brother Laser Printer"
class TestQueryUsbPjl:
def test_success(self) -> None:
with (
patch(f"{MOD}.find_usb_printer_dev", return_value="/dev/usb/lp0"),
patch(f"{MOD}._init_usb_result") as mock_init,
patch(f"{MOD}.os.access", return_value=True),
patch(f"{MOD}.os.open", return_value=10) as mock_open,
patch(f"{MOD}._run_pjl_queries"),
patch(f"{MOD}.os.close"),
):
mock_init.return_value = USBResult(
device="/dev/usb/lp0",
status_code="10001",
)
result = query_usb_pjl()
assert result.device == "/dev/usb/lp0"
assert result.error == ""
# The whole point: a blocking open() hangs on an unwell printer.
assert mock_open.call_args[0][1] & os.O_NONBLOCK
@patch(f"{MOD}.find_usb_printer_dev", return_value=None)
def test_no_dev_falls_back_to_cups(self, f: MagicMock) -> None:
with patch(
"python_pkg.brother_printer._cups_fallback.query_usb_via_cups",
) as mock_cups:
mock_cups.return_value = USBResult(device="cups")
result = query_usb_pjl()
assert result.device == "cups"
@patch(f"{MOD}.os.access", return_value=False)
@patch(f"{MOD}._init_usb_result")
@patch(f"{MOD}.find_usb_printer_dev", return_value="/dev/usb/lp0")
def test_permission_denied(
self,
f: MagicMock,
mock_init: MagicMock,
a: MagicMock,
) -> None:
mock_init.return_value = USBResult(device="/dev/usb/lp0")
result = query_usb_pjl()
assert "Permission denied" in result.error
def test_silent_printer_is_reported_not_hidden(self) -> None:
"""A printer that answers nothing must say so, not look healthy."""
with (
patch(f"{MOD}.find_usb_printer_dev", return_value="/dev/usb/lp0"),
patch(f"{MOD}._init_usb_result") as mock_init,
patch(f"{MOD}.os.access", return_value=True),
patch(f"{MOD}.os.open", return_value=10),
patch(f"{MOD}._run_pjl_queries"),
patch(f"{MOD}.os.close"),
):
mock_init.return_value = USBResult(device="/dev/usb/lp0")
result = query_usb_pjl()
assert "did not answer" in result.error
def test_busy_device_explains_why(self) -> None:
"""EBUSY means CUPS holds the printer mid-job; say that."""
exc = OSError("busy")
exc.errno = errno.EBUSY
with (
patch(f"{MOD}.find_usb_printer_dev", return_value="/dev/usb/lp0"),
patch(f"{MOD}._init_usb_result") as mock_init,
patch(f"{MOD}.os.access", return_value=True),
patch(f"{MOD}.os.open", side_effect=exc),
):
mock_init.return_value = USBResult(device="/dev/usb/lp0")
result = query_usb_pjl()
assert "busy" in result.error.lower()
def test_eacces_suggests_sudo(self) -> None:
exc = OSError("denied")
exc.errno = errno.EACCES
with (
patch(f"{MOD}.find_usb_printer_dev", return_value="/dev/usb/lp0"),
patch(f"{MOD}._init_usb_result") as mock_init,
patch(f"{MOD}.os.access", return_value=True),
patch(f"{MOD}.os.open", side_effect=exc),
):
mock_init.return_value = USBResult(device="/dev/usb/lp0")
result = query_usb_pjl()
assert "sudo" in result.error
@patch(f"{MOD}.os.open", side_effect=OSError("no device"))
@patch(f"{MOD}.os.access", return_value=True)
@patch(f"{MOD}._init_usb_result")
@patch(f"{MOD}.find_usb_printer_dev", return_value="/dev/usb/lp0")
def test_oserror_fd_none(
self,
f: MagicMock,
mock_init: MagicMock,
a: MagicMock,
o: MagicMock,
) -> None:
"""os.open raises OSError before fd is set -> fd stays None."""
mock_init.return_value = USBResult(device="/dev/usb/lp0")
result = query_usb_pjl()
assert "no device" in result.error