Separate method open() and constructor, enhance consistency between connectors: Rework printer tests (#587)

* Add fixtures
* Add test_printer_file.py
* Remove old broken printer tests
* Include a close_on_reopen test
* Add test_printer_network.py
* Add test_printer_serial.py
* Add test_printer_usb.py
* Add test_printer_lp.py
* Add test_printer_cups.py
* Add test_printer_win32raw.py
* Test the 'printers' property
* Fix conftest import formatting
* Fix failing LP tests
* Cancel close only if literal False|None _device
* Fix win32raw failing tests (maybe)
* Include win32raw close_on_reopen test
* Include test _raw methods to win32raw
* Replace general exceptions in win32raw
* Replace wrong exception in cups
* Include more tests to cups
* Extend cups tests

test/test_printers/test_printer_win32raw.py

@@ -0,0 +1,177 @@
+#!/usr/bin/python
+#  -*- coding: utf-8 -*-
+"""tests for the Win32Raw printer
+
+:author: Benito López and the python-escpos developers
+:organization: `python-escpos <https://github.com/python-escpos>`_
+:copyright: Copyright (c) 2023 `python-escpos <https://github.com/python-escpos>`_
+:license: MIT
+"""
+
+import logging
+import sys
+
+import pytest
+
+# skip all the tests if the platform is not Windows
+pytestmark = pytest.mark.skipif(
+    sys.platform != "win32", reason="Skipping Windows platform specific tests"
+)
+
+
+def test_device_not_initialized(win32rawprinter):
+    """
+    GIVEN a win32raw printer object
+    WHEN it is not initialized
+    THEN check the device property is False
+    """
+    assert win32rawprinter._device is False
+
+
+def test_open_raise_exception(win32rawprinter, devicenotfounderror):
+    """
+    GIVEN a win32raw printer object
+    WHEN open() is set to raise a DeviceNotFoundError on error
+    THEN check the exception is raised
+    """
+    win32rawprinter.printer_name = "fake_printer"
+
+    with pytest.raises(devicenotfounderror):
+        win32rawprinter.open(raise_not_found=True)
+
+
+def test_open_not_raise_exception(win32rawprinter, caplog):
+    """
+    GIVEN a win32raw printer object
+    WHEN open() is set to not raise on error but simply cancel
+    THEN check the error is logged and open() canceled
+    """
+    win32rawprinter.printer_name = "fake_printer"
+
+    with caplog.at_level(logging.ERROR):
+        win32rawprinter.open(raise_not_found=False)
+
+    assert "not available" in caplog.text
+    assert win32rawprinter.device is None
+
+
+def test_open(win32rawprinter, caplog, mocker):
+    """
+    GIVEN a win32raw printer object and a mocked win32printer device
+    WHEN a valid connection to a device is opened
+    THEN check the success is logged and the device property is set
+    """
+    # The _win32typing.PyPrinterHANDLE object is unreachable, so we have to mock it
+    PyPrinterHANDLE = mocker.Mock()
+    PyPrinterHANDLE.return_value = 0  # Accepts 0 or None as return value
+
+    # Replace the contents of Win32Raw.printers to accept test_printer as a system's printer name
+    mocker.patch("escpos.printer.Win32Raw.printers", new={"test_printer": "Test"})
+
+    # Configure and assert printer_name is valid
+    win32rawprinter.printer_name = "test_printer"
+    assert win32rawprinter.printer_name in win32rawprinter.printers
+
+    with caplog.at_level(logging.INFO):
+        # Patch the win32print.OpenPrinter method to return the mocked PyPrinterHANDLE
+        mocker.patch("win32print.OpenPrinter", new=PyPrinterHANDLE)
+        win32rawprinter.open()
+
+    assert "enabled" in caplog.text
+    assert win32rawprinter.device == PyPrinterHANDLE.return_value
+
+
+def test_close_on_reopen(win32rawprinter, mocker):
+    """
+    GIVEN a win32raw printer object and a mocked win32print device
+    WHEN a valid connection to a device is reopened before close
+    THEN check the close method is called if _device
+    """
+    # The _win32typing.PyPrinterHANDLE object is unreachable, so we have to mock it
+    PyPrinterHANDLE = mocker.Mock()
+    PyPrinterHANDLE.return_value = 0  # Accepts 0 or None as return value
+
+    # Replace the contents of Win32Raw.printers to accept test_printer as a system's printer name
+    mocker.patch("escpos.printer.Win32Raw.printers", new={"test_printer": "Test"})
+
+    # Configure printer_name
+    win32rawprinter.printer_name = "test_printer"
+
+    # Patch the win32print.OpenPrinter method to return the mocked PyPrinterHANDLE
+    mocker.patch("win32print.OpenPrinter", new=PyPrinterHANDLE)
+    # Patch the win32print close methods
+    mocker.patch("win32print.EndPagePrinter")
+    mocker.patch("win32print.EndDocPrinter")
+    mocker.patch("win32print.ClosePrinter")
+
+    spy = mocker.spy(win32rawprinter, "close")
+    # Simulate a reopen before close
+    win32rawprinter._device = True
+    win32rawprinter.open()
+
+    spy.assert_called_once()
+
+
+def test_close(win32rawprinter, caplog, mocker):
+    """
+    GIVEN a win32raw printer object and a mocked win32print device
+    WHEN a connection is opened and closed
+    THEN check the closing is logged and the device property is False
+    """
+    # The _win32typing.PyPrinterHANDLE object is unreachable, so we have to mock it
+    PyPrinterHANDLE = mocker.Mock()
+    PyPrinterHANDLE.return_value = 0  # Accepts 0 or None as return value
+
+    # Replace the contents of Win32Raw.printers to accept test_printer as a system's printer name
+    mocker.patch("escpos.printer.Win32Raw.printers", new={"test_printer": "Test"})
+
+    # Configure and assert printer_name is valid
+    win32rawprinter.printer_name = "test_printer"
+    assert win32rawprinter.printer_name in win32rawprinter.printers
+
+    # Patch the win32print.OpenPrinter method to return the mocked PyPrinterHANDLE
+    mocker.patch("win32print.OpenPrinter", new=PyPrinterHANDLE)
+    win32rawprinter.open()
+    with caplog.at_level(logging.INFO):
+        # Patch the win32print close methods
+        # Raises a warning but passes the test
+        mocker.patch("win32print.EndPagePrinter")
+        mocker.patch("win32print.EndDocPrinter")
+        mocker.patch("win32print.ClosePrinter")
+        win32rawprinter.close()
+
+    assert "Closing" in caplog.text
+    assert win32rawprinter._device is False
+
+
+def test_raw_raise_exception(win32rawprinter, devicenotfounderror):
+    """
+    GIVEN a win32raw printer object and a mocked win32print device
+    WHEN calling _raw() before configuring the connection
+    THEN check an exception is raised
+    """
+    win32rawprinter.printer_name = None
+    with pytest.raises(devicenotfounderror):
+        win32rawprinter._raw(b"Test error")
+
+    win32rawprinter.printer_name = "fake_printer"
+    win32rawprinter.device = None
+    with pytest.raises(devicenotfounderror):
+        win32rawprinter._raw(b"Test error")
+
+
+def test_raw(win32rawprinter, mocker):
+    """
+    GIVEN a win32raw printer object and a mocked win32print device
+    WHEN calling _raw() after a valid connection
+    THEN check the underlying method is correctly called
+    """
+    PyPrinterHANDLE = mocker.Mock()
+    PyPrinterHANDLE.return_value = 0
+
+    mocked_writer = mocker.patch("win32print.WritePrinter")
+
+    win32rawprinter._device = PyPrinterHANDLE
+    win32rawprinter._raw(b"Test error")
+
+    mocked_writer.assert_called_once_with(PyPrinterHANDLE, b"Test error")