Add unit test suite for ESP32 Dimmer Driver library

.gitignore

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+_codeql_detected_source_root

README.md

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 If you are using the library in a project that is not using ESP-IDF 5.x, you can still use the old version of the library (v1.0.0) which is compatible with ESP-IDF 4.x.
 
+## Testing
+
+This library includes comprehensive unit tests to ensure reliability and enable safe refactoring. The tests cover all public API functions including:
+
+- Dimmer creation and initialization
+- Power control with boundary conditions
+- State management (ON/OFF)
+- Mode management (NORMAL/TOGGLE)
+- Multiple independent dimmers
+
+### Running Tests
+
+To run the unit tests:
+
+```bash
+cd test_app
+idf.py set-target esp32
+idf.py build
+idf.py -p /dev/ttyUSB0 flash monitor
+```
+
+See [test_app/README.md](test_app/README.md) for detailed testing documentation.
+
 ## Contributing 
 
 We welcome contributions to this library. Please open a pull request or an issue to get started. 

TESTING.md

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+# Testing Guide for ESP32 Dimmer Driver
+
+## Overview
+
+This guide provides instructions for running and extending the unit tests for the ESP32 Dimmer Driver library.
+
+## Test Coverage Summary
+
+The unit test suite covers 19 test cases across the following categories:
+
+### 1. Dimmer Creation (2 tests)
+- Creating a single dimmer instance
+- Creating multiple dimmer instances with different GPIO pins
+
+### 2. Power Control (3 tests)
+- Setting and getting power with normal values (0, 50, 99)
+- Boundary value testing (values >99 are clamped)
+- Power retrieval when dimmer is OFF
+
+### 3. State Management (3 tests)
+- Setting and getting ON/OFF state
+- Toggling state with changeState()
+- State's effect on getPower() return value
+
+### 4. Mode Management (3 tests)
+- Setting and getting NORMAL/TOGGLE modes
+- Toggle settings with valid ranges
+- Toggle settings with boundary values
+
+### 5. Initialization (2 tests)
+- Initialization with NORMAL_MODE
+- Initialization with TOGGLE_MODE
+
+### 6. Multiple Dimmers (1 test)
+- Independent operation of multiple dimmers
+
+### 7. GPIO and Timer ISR (5 tests)
+- GPIO output timing after zero-crossing events
+- Pulse width timing on GPIO output
+- Dimmer response to zero-crossing interrupts
+- Multiple dimmers controlling GPIO pins independently
+- Timer ISR respecting dimmer state changes (ON/OFF)
+
+### 8. Integration (1 test)
+- State changes affecting power reporting
+
+## Prerequisites
+
+### Software Requirements
+- ESP-IDF v5.0 or higher
+- Python 3.7 or higher (for ESP-IDF)
+- CMake 3.16 or higher
+- Appropriate compiler toolchain for your platform
+
+### Hardware Requirements
+- ESP32 development board (any variant: ESP32, ESP32-S2, ESP32-C3, etc.)
+- USB cable for flashing and monitoring
+- (Optional) Oscilloscope for hardware validation
+
+## Installation
+
+1. Install ESP-IDF v5.0 or higher following the [official guide](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/get-started/index.html)
+
+2. Clone this repository:
+   ```bash
+   git clone https://github.com/pmarchini/Esp32Dimmer.git
+   cd Esp32Dimmer
+   ```
+
+## Running Tests
+
+### Quick Start
+
+```bash
+# Navigate to test application
+cd test_app
+
+# Set target (choose your ESP32 variant)
+idf.py set-target esp32
+
+# Build the tests
+idf.py build
+
+# Flash and monitor (replace with your serial port)
+idf.py -p /dev/ttyUSB0 flash monitor
+```
+
+### Supported Targets
+
+The tests can run on any ESP32 variant:
+- ESP32 (default)
+- ESP32-S2
+- ESP32-C3
+- ESP32-S3
+
+To set a specific target:
+```bash
+idf.py set-target esp32s3
+```
+
+### Build Options
+
+For verbose build output:
+```bash
+idf.py -v build
+```
+
+For clean build:
+```bash
+idf.py fullclean
+idf.py build
+```
+
+## Understanding Test Output
+
+### Successful Test Run
+
+```
+========================================
+ESP32 Dimmer Driver Unit Tests
+========================================
+
+Running test_createDimmer_returns_valid_pointer...
+PASS
+
+Running test_createDimmer_with_different_pins...
+PASS
+
+[... more tests ...]
+
+========================================
+All tests completed!
+========================================
+
+16 Tests 0 Failures 0 Ignored
+OK
+```
+
+### Failed Test Example
+
+If a test fails, you'll see:
+```
+Running test_setPower_getPower_normal_values...
+test_main.c:56:test_setPower_getPower_normal_values:FAIL: Expected 50 Was 0
+
+16 Tests 1 Failures 0 Ignored
+FAIL
+```
+
+## Writing New Tests
+
+### Test Function Template
+
+```c
+void test_your_feature_description(void)
+{
+    // 1. Setup - Create dimmer and initialize
+    dimmertyp *dimmer = createDimmer(TEST_TRIAC_GPIO, TEST_ZC_GPIO);
+    TEST_ASSERT_NOT_NULL(dimmer);
+    begin(dimmer, NORMAL_MODE, ON, 50);
+
+    // 2. Execute - Perform the operation you're testing
+    setPower(dimmer, 42);
+    vTaskDelay(pdMS_TO_TICKS(10));
+
+    // 3. Verify - Check the results
+    TEST_ASSERT_EQUAL(42, getPower(dimmer));
+
+    // 4. Cleanup (if needed)
+    // Note: Library doesn't provide cleanup functions
+}
+```
+
+### Unity Assertion Macros
+
+Common assertions used in the tests:
+
+```c
+TEST_ASSERT_TRUE(condition)           // Verify condition is true
+TEST_ASSERT_FALSE(condition)          // Verify condition is false
+TEST_ASSERT_EQUAL(expected, actual)   // Verify values are equal
+TEST_ASSERT_NOT_EQUAL(val1, val2)     // Verify values are different
+TEST_ASSERT_NULL(pointer)             // Verify pointer is NULL
+TEST_ASSERT_NOT_NULL(pointer)         // Verify pointer is not NULL
+TEST_ASSERT_EQUAL_INT(exp, act)       // Compare integers
+TEST_ASSERT_GREATER_THAN(threshold, actual) // Verify actual > threshold
+TEST_ASSERT_LESS_THAN(threshold, actual)    // Verify actual < threshold
+```
+
+### Adding a New Test
+
+1. Add test function to `test_app/main/test_main.c`:
+   ```c
+   void test_my_new_feature(void)
+   {
+       // Your test code here
+   }
+   ```
+
+2. Register it in `app_main()`:
+   ```c
+   void app_main(void)
+   {
+       UNITY_BEGIN();
+
+       // Existing tests...
+       RUN_TEST(test_my_new_feature);  // Add this line
+
+       UNITY_END();
+   }
+   ```
+
+3. Rebuild and test:
+   ```bash
+   idf.py build flash monitor
+   ```
+
+## Test Best Practices
+
+### 1. Test Independence
+Each test should be independent and not rely on state from other tests.
+
+### 2. Descriptive Names
+Use clear, descriptive test names: `test_<component>_<scenario>`
+- Good: `test_setPower_boundary_values`
+- Bad: `test_power_1`
+
+### 3. Test One Thing
+Each test should verify one specific behavior.
+
+### 4. Use Delays
+When testing asynchronous operations, add small delays:
+```c
+setPower(dimmer, 50);
+vTaskDelay(pdMS_TO_TICKS(10)); // Allow setting to take effect
+TEST_ASSERT_EQUAL(50, getPower(dimmer));
+```
+
+### 5. Document Edge Cases
+Add comments for non-obvious test cases:
+```c
+// Test that power values above 99 are clamped to 99
+setPower(dimmer, 150);
+TEST_ASSERT_EQUAL(99, getPower(dimmer));
+```
+
+## Continuous Integration
+
+### GitHub Actions Example
+
+Create `.github/workflows/test.yml`:
+
+```yaml
+name: ESP32 Dimmer Tests
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Setup ESP-IDF
+        uses: espressif/esp-idf-ci-action@v1
+        with:
+          esp_idf_version: v5.0
+          target: esp32
+      - name: Build Tests
+        run: |
+          cd test_app
+          idf.py build
+```
+
+## Troubleshooting
+
+### Build Errors
+
+**Error: "No such file or directory" for esp32-triac-dimmer-driver.h**
+- Solution: Ensure EXTRA_COMPONENT_DIRS is set correctly in test_app/CMakeLists.txt
+
+**Error: "undefined reference to unity_*"**
+- Solution: Ensure unity is in the REQUIRES list in main/CMakeLists.txt
+
+### Runtime Issues
+
+**Tests fail to start**
+- Check serial port permissions: `sudo usermod -a -G dialout $USER`
+- Verify correct serial port: `ls /dev/tty*`
+
+**Random test failures**
+- Hardware interference - ensure stable power supply
+- Increase delay times in tests
+- Check for race conditions in test logic
+
+### Memory Issues
+
+**Stack overflow in tests**
+- Increase CONFIG_ESP_MAIN_TASK_STACK_SIZE in sdkconfig.defaults
+
+**Heap allocation failures**
+- Tests may exceed ALL_DIMMERS limit (50)
+- Reset the board between test runs
+
+## Hardware Validation Testing
+
+While unit tests validate software behavior, hardware testing validates actual dimmer operation:
+
+### Setup for Hardware Tests
+1. Connect zero-crossing detector to GPIO_NUM_21
+2. Connect TRIAC outputs to GPIO_NUM_22 and GPIO_NUM_23
+3. Connect dimmable AC load (e.g., incandescent bulb)
+4. Use oscilloscope to monitor TRIAC firing pulses
+
+### Safety Warnings
+⚠️ **AC VOLTAGE HAZARD** ⚠️
+- Only qualified personnel should work with AC circuits
+- Ensure proper isolation and grounding
+- Use current-limited test circuits
+- Never touch circuits while powered
+
+## Future Enhancements
+
+Potential areas for test expansion:
+
+1. **Performance Tests**
+   - Measure ISR timing
+   - Verify zero-crossing detection accuracy
+   - Test rapid power changes
+
+2. **Stress Tests**
+   - Maximum dimmer count (50 dimmers)
+   - Continuous operation for extended periods
+   - Rapid state/mode changes
+
+3. **Hardware-in-the-Loop Tests**
+   - Actual zero-crossing signal simulation
+   - TRIAC timing verification
+   - Multi-frequency testing (50Hz/60Hz)
+
+4. **Error Handling Tests**
+   - Invalid GPIO pins
+   - Null pointer handling
+   - Resource exhaustion scenarios
+
+## References
+
+- [ESP-IDF Unit Testing Guide](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-guides/unit-tests.html)
+- [Unity Testing Framework](https://github.com/ThrowTheSwitch/Unity)
+- [ESP32 GPIO Documentation](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/gpio.html)
+
+## Support
+
+For questions or issues:
+- Open an issue on [GitHub](https://github.com/pmarchini/Esp32Dimmer/issues)
+- Check existing issues and discussions
+- Review the test code for examples

test_app/.gitignore

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+build/
+sdkconfig
+sdkconfig.old
+*.swp
+*.swo
+*.pyc
+dependencies.lock
+managed_components/