feat: Set up comprehensive Python testing infrastructure with Poetry

.gitignore

@@ -1 +1,34 @@
 *.pyc
+
+# Testing
+.pytest_cache/
+.coverage
+htmlcov/
+coverage.xml
+.tox/
+
+# Build artifacts
+build/
+dist/
+*.egg-info/
+__pycache__/
+
+# Virtual environments
+venv/
+env/
+.env
+.venv/
+
+# IDE files
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# Claude settings
+.claude/*
+
+# OS files
+.DS_Store
+Thumbs.db

pyproject.toml

@@ -0,0 +1,83 @@
+[tool.poetry]
+name = "shiftpi"
+version = "0.2"
+description = "ShiftPi is the easiest way to work with 74HC595 shift registers on your Raspberry Pi in Arduino style :). If you are an Arduino fan ... you'l love it :)"
+authors = ["Marian Ignev <m@ignev.net>"]
+readme = "README.md"
+homepage = "http://m.ignev.net/code/shiftpi"
+packages = [{include = "shiftpi.py"}]
+classifiers = [
+    "Operating System :: POSIX",
+    "Operating System :: POSIX :: BSD",
+    "Operating System :: POSIX :: Linux",
+    "Operating System :: Unix",
+    "Programming Language :: Python",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.11",
+    "Topic :: System :: Shells",
+    "Topic :: Utilities",
+]
+
+[tool.poetry.dependencies]
+python = "^3.11"
+# RPi.GPIO = "*"  # Uncommented from original setup.py
+
+[tool.poetry.group.test.dependencies]
+pytest = "^7.4.0"
+pytest-cov = "^4.1.0"
+pytest-mock = "^3.11.0"
+
+[tool.poetry.scripts]
+test = "pytest:main"
+tests = "pytest:main"
+
+[build-system]
+requires = ["poetry-core"]
+build-backend = "poetry.core.masonry.api"
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+python_files = ["test_*.py", "*_test.py"]
+python_classes = ["Test*"]
+python_functions = ["test_*"]
+addopts = [
+    "--strict-markers",
+    "--strict-config",
+    "--verbose",
+    "--cov=shiftpi",
+    "--cov-report=term-missing",
+    "--cov-report=html:htmlcov",
+    "--cov-report=xml:coverage.xml",
+    "--cov-fail-under=80",
+]
+markers = [
+    "unit: marks tests as unit tests (fast isolated tests)",
+    "integration: marks tests as integration tests (slower tests with dependencies)",
+    "slow: marks tests as slow running tests",
+]
+
+[tool.coverage.run]
+source = ["shiftpi"]
+omit = [
+    "tests/*",
+    "setup.py",
+    "*/__init__.py",
+]
+
+[tool.coverage.report]
+exclude_lines = [
+    "pragma: no cover",
+    "def __repr__",
+    "raise AssertionError",
+    "raise NotImplementedError",
+    "if __name__ == .__main__.:",
+    "if TYPE_CHECKING:",
+]
+show_missing = true
+precision = 2
+
+[tool.coverage.html]
+directory = "htmlcov"
+
+[tool.coverage.xml]
+output = "coverage.xml"

shiftpi.py

@@ -65,7 +65,7 @@ def startupMode(mode, execute = False):
         else:
             raise ValueError("The mode can be only HIGH or LOW or Dictionary with specific pins and modes")
     elif isinstance(mode, dict):
-        for pin, mode in mode.iteritems():
+        for pin, mode in mode.items():
             _setPin(pin, mode)
         if execute:
             _execute()

tests/conftest.py

@@ -0,0 +1,101 @@
+"""
+Shared pytest fixtures for the shiftpi testing suite.
+"""
+
+import pytest
+import tempfile
+import os
+import shutil
+import sys
+from unittest.mock import Mock, patch, MagicMock
+
+# Mock RPi.GPIO at module level to allow imports
+mock_gpio = MagicMock()
+mock_gpio.BCM = 'BCM'
+mock_gpio.OUT = 'OUT'
+mock_gpio.HIGH = 1
+mock_gpio.LOW = 0
+mock_gpio.setmode = Mock()
+mock_gpio.setwarnings = Mock()
+mock_gpio.setup = Mock()
+mock_gpio.output = Mock()
+
+sys.modules['RPi'] = MagicMock()
+sys.modules['RPi.GPIO'] = mock_gpio
+
+
+@pytest.fixture
+def temp_dir():
+    """Create a temporary directory for tests."""
+    temp_path = tempfile.mkdtemp()
+    yield temp_path
+    shutil.rmtree(temp_path)
+
+
+@pytest.fixture
+def mock_gpio():
+    """Mock RPi.GPIO module for testing without hardware."""
+    with patch('shiftpi.GPIO') as mock_gpio_module:
+        mock_gpio_module.BCM = 'BCM'
+        mock_gpio_module.OUT = 'OUT'
+        mock_gpio_module.HIGH = 1
+        mock_gpio_module.LOW = 0
+
+        mock_gpio_module.setmode = Mock()
+        mock_gpio_module.setwarnings = Mock()
+        mock_gpio_module.setup = Mock()
+        mock_gpio_module.output = Mock()
+
+        yield mock_gpio_module
+
+
+@pytest.fixture
+def mock_config():
+    """Provide a mock configuration for testing."""
+    return {
+        'ser_pin': 25,
+        'rclk_pin': 24,
+        'srclk_pin': 23,
+        'num_registers': 1
+    }
+
+
+@pytest.fixture
+def sample_pin_states():
+    """Provide sample pin states for testing."""
+    return [0, 1, 0, 1, 1, 0, 1, 0]  # 8 pins worth of test data
+
+
+@pytest.fixture(autouse=True)
+def reset_shiftpi_globals():
+    """Reset shiftpi global variables before each test."""
+    import shiftpi
+
+    # Reset global variables to their initial state
+    shiftpi._SER_pin = 25
+    shiftpi._RCLK_pin = 24
+    shiftpi._SRCLK_pin = 23
+    shiftpi._registers = list()
+    shiftpi._number_of_shiftregisters = 1
+
+    yield
+
+    # Clean up after test
+    shiftpi._registers = list()
+
+
+@pytest.fixture
+def temp_file():
+    """Create a temporary file for tests."""
+    fd, temp_path = tempfile.mkstemp()
+    os.close(fd)
+    yield temp_path
+    if os.path.exists(temp_path):
+        os.remove(temp_path)
+
+
+@pytest.fixture
+def mock_sleep():
+    """Mock time.sleep for faster tests."""
+    with patch('shiftpi.sleep') as mock_sleep_func:
+        yield mock_sleep_func

tests/test_setup_validation.py

@@ -0,0 +1,76 @@
+"""
+Validation tests to ensure the testing infrastructure is properly set up.
+"""
+
+import pytest
+import os
+import sys
+
+
+def test_pytest_is_working():
+    """Basic test to ensure pytest is running correctly."""
+    assert True
+
+
+def test_project_structure():
+    """Test that the project structure is as expected."""
+    # Check that main module exists
+    assert os.path.exists('shiftpi.py')
+
+    # Check that testing directories exist
+    assert os.path.isdir('tests')
+    assert os.path.isdir('tests/unit')
+    assert os.path.isdir('tests/integration')
+
+
+def test_shiftpi_import():
+    """Test that the main shiftpi module can be imported."""
+    try:
+        import shiftpi
+        assert hasattr(shiftpi, 'version')
+        assert shiftpi.version == "0.2"
+    except ImportError:
+        pytest.fail("Could not import shiftpi module")
+
+
+def test_fixtures_available(temp_dir, mock_config):
+    """Test that shared fixtures from conftest.py are available."""
+    # Test temp_dir fixture
+    assert os.path.isdir(temp_dir)
+
+    # Test mock_config fixture
+    assert isinstance(mock_config, dict)
+    assert 'ser_pin' in mock_config
+
+
+def test_mock_gpio_fixture(mock_gpio):
+    """Test that GPIO mocking fixture works."""
+    assert mock_gpio is not None
+    assert hasattr(mock_gpio, 'setup')
+    assert hasattr(mock_gpio, 'output')
+
+
+@pytest.mark.unit
+def test_unit_marker():
+    """Test that custom markers work."""
+    assert True
+
+
+@pytest.mark.integration
+def test_integration_marker():
+    """Test that custom markers work."""
+    assert True
+
+
+@pytest.mark.slow
+def test_slow_marker():
+    """Test that custom markers work."""
+    assert True
+
+
+def test_coverage_measurement():
+    """Test that this test file is being measured for coverage."""
+    # This test itself helps ensure coverage measurement is working
+    # by providing a test that will show up in coverage reports
+    covered_line = True
+    assert covered_line