Tests added, see the documentation in the tests directory for details. Improved the socket code.

tests/README.md

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+# Fenrir Test Suite
+
+This directory contains automated tests for the Fenrir screen reader. Testing a screen reader that requires root access and hardware interaction presents unique challenges, so we use a multi-layered testing strategy.
+
+## Test Strategy
+
+### 1. Unit Tests (No Root Required)
+Test individual components in isolation without requiring hardware access:
+- **Core Managers**: Logic testing without driver dependencies
+- **Utility Functions**: String manipulation, cursor calculations, text processing
+- **Settings Validation**: Configuration parsing and validation
+- **Remote Command Parsing**: Command/setting string processing
+
+### 2. Integration Tests (No Root Required)
+Test component interactions using mocked drivers:
+- **Remote Control**: Unix socket and TCP communication
+- **Command System**: Command loading and execution flow
+- **Event Processing**: Event queue and dispatching
+- **Settings Manager**: Configuration loading and runtime changes
+
+### 3. Driver Tests (Root Required, Optional)
+Test actual hardware interaction (only run in CI or explicitly by developers):
+- **VCSA Driver**: Screen reading on real TTY
+- **Evdev Driver**: Keyboard input capture
+- **Speech Drivers**: TTS output validation
+- **Sound Drivers**: Audio playback testing
+
+### 4. End-to-End Tests (Root Required, Manual)
+Real-world usage scenarios run manually by developers:
+- Full Fenrir startup/shutdown cycle
+- Remote control from external scripts
+- VMenu navigation and command execution
+- Speech output for screen changes
+
+## Running Tests
+
+```bash
+# Install test dependencies
+pip install pytest pytest-cov pytest-mock pytest-timeout
+
+# Run all unit and integration tests (no root required)
+pytest tests/
+
+# Run with coverage report
+pytest tests/ --cov=src/fenrirscreenreader --cov-report=html
+
+# Run only unit tests
+pytest tests/unit/
+
+# Run only integration tests
+pytest tests/integration/
+
+# Run specific test file
+pytest tests/unit/test_settings_manager.py
+
+# Run with verbose output
+pytest tests/ -v
+
+# Run driver tests (requires root)
+sudo pytest tests/drivers/ -v
+```
+
+## Test Organization
+
+```
+tests/
+├── README.md                    # This file
+├── conftest.py                  # Shared pytest fixtures
+├── unit/                        # Unit tests (fast, no mocking needed)
+│   ├── test_settings_validation.py
+│   ├── test_cursor_utils.py
+│   ├── test_text_utils.py
+│   └── test_remote_parsing.py
+├── integration/                 # Integration tests (require mocking)
+│   ├── test_remote_control.py
+│   ├── test_command_manager.py
+│   ├── test_event_manager.py
+│   └── test_settings_manager.py
+└── drivers/                     # Driver tests (require root)
+    ├── test_vcsa_driver.py
+    ├── test_evdev_driver.py
+    └── test_speech_drivers.py
+```
+
+## Writing Tests
+
+### Example Unit Test
+```python
+def test_speech_rate_validation():
+    """Test that speech rate validation rejects out-of-range values."""
+    manager = SettingsManager()
+
+    # Valid values should pass
+    manager._validate_setting_value('speech', 'rate', 0.5)
+    manager._validate_setting_value('speech', 'rate', 3.0)
+
+    # Invalid values should raise ValueError
+    with pytest.raises(ValueError):
+        manager._validate_setting_value('speech', 'rate', -1.0)
+    with pytest.raises(ValueError):
+        manager._validate_setting_value('speech', 'rate', 10.0)
+```
+
+### Example Integration Test
+```python
+def test_remote_control_unix_socket(tmp_path):
+    """Test Unix socket remote control accepts commands."""
+    socket_path = tmp_path / "test.sock"
+
+    # Start mock remote driver
+    driver = MockUnixDriver(socket_path)
+
+    # Send command
+    send_remote_command(socket_path, "command say Hello")
+
+    # Verify command was received
+    assert driver.received_commands[-1] == "command say Hello"
+```
+
+## Test Coverage Goals
+
+- **Unit Tests**: 80%+ coverage on utility functions and validation logic
+- **Integration Tests**: 60%+ coverage on core managers and command system
+- **Overall**: 70%+ coverage on non-driver code
+
+Driver code is excluded from coverage metrics as it requires hardware interaction.
+
+## Continuous Integration
+
+Tests are designed to run in CI environments without root access:
+- Unit and integration tests run on every commit
+- Driver tests are skipped in CI (require actual hardware)
+- Coverage reports are generated and tracked over time
+
+## Test Principles
+
+1. **No Root by Default**: Most tests should run without elevated privileges
+2. **Fast Execution**: Unit tests complete in <1 second each
+3. **Isolated**: Tests don't depend on each other or external state
+4. **Deterministic**: Tests produce same results every run
+5. **Documented**: Each test has a clear docstring explaining what it tests
+6. **Realistic Mocks**: Mocked components behave like real ones
+
+## Future Enhancements
+
+- **Performance Tests**: Measure input-to-speech latency
+- **Stress Tests**: Rapid event processing, memory leak detection
+- **Accessibility Tests**: Verify all features work without vision
+- **Compatibility Tests**: Test across different Linux distributions