//! TDD tests for device fallback handling
//! These tests define expected behavior for device creation without cpu feature

use rtx_tensor::Device;

#[test]
fn test_device_default_creation() {
    // Test creating default device (should work without cpu feature)
    let device = Device::default();

    // Device should be valid
    match device {
        Device::Cuda(_) => {
            // CUDA device is valid
        }
        _ => {
            // Other devices are valid too
        }
    }
}

#[test]
fn test_device_cuda_with_fallback() {
    // Test CUDA creation with fallback to default
    let device = Device::cuda(0).unwrap_or(Device::default());

    // Should have a valid device
    match device {
        Device::Cuda(_) => {
            // CUDA device worked
        }
        _ => {
            // Fallback worked
        }
    }
}

#[test]
fn test_device_fallback_pattern() {
    // Test the pattern we'll use to replace Device::cpu()
    let device = get_fallback_device();

    // Should return a valid device
    match device {
        Device::Cuda(_) => {
            // CUDA device
        }
        _ => {
            // Default device
        }
    }
}

// Helper function that replaces Device::cpu() calls
fn get_fallback_device() -> Device {
    Device::cuda(0).unwrap_or(Device::default())
}