# IMU Data Simulator Unit Tests

Unit tests for the `DataSimulator` (IMU) node are implemented in `src/g2_2025_odometry_pkg/test/test_imu_simulator.cpp` using Google Test and ROS2 test utilities. The tests validate node initialization, message publishing, and data correctness.

## Test Cases

### 1. NodeInitialization

**Description:** Verifies that the DataSimulator node can be created without errors.

- **Test Action:** Create DataSimulator instance
- **Expected Result:** No exceptions thrown during construction

### 2. MessagePublishing

**Description:** Tests that IMU messages are published on the correct topic.

- **Test Action:**
  - Create subscription to `simulated_imu_data` topic
  - Create DataSimulator node
  - Spin both nodes for a short period
- **Expected Result:** At least one `sensor_msgs/msg/Imu` message is received

### 3. MessageFrameId

**Description:** Verifies that published IMU messages have the correct frame_id.

- **Test Action:**
  - Subscribe to `simulated_imu_data`
  - Receive a message
- **Expected Result:** `header.frame_id` equals `"imu_link"`

### 4. LinearAccelerationValues

**Description:** Tests that linear acceleration values are valid (finite numbers).

- **Test Action:**
  - Subscribe and receive IMU message
  - Check linear_acceleration fields
- **Expected Result:**
  - `linear_acceleration.x` is finite
  - `linear_acceleration.y` is finite
  - `linear_acceleration.z` is finite

### 5. AngularVelocityValues

**Description:** Tests that angular velocity values are valid (finite numbers).

- **Test Action:**
  - Subscribe and receive IMU message
  - Check angular_velocity fields
- **Expected Result:**
  - `angular_velocity.x` is finite
  - `angular_velocity.y` is finite
  - `angular_velocity.z` is finite

## Test Infrastructure

The test class `IMUSimulatorTest` provides:
- Static `SetUpTestSuite()` and `TearDownTestSuite()` for ROS2 init/shutdown
- Helper method `setupBasicIMUParams()` for setting up default test parameters

## ROS2 Topics Used

| Topic | Message Type | Direction |
|-------|--------------|-----------|
| `simulated_imu_data` | sensor_msgs/msg/Imu | Published by node under test |