# Testing Guide

## Test Environment

The testing environment uses podman-compose to create a network topology with routers and an ICMP target:

```
┌─────────────────┐    ┌─────────────────┐    ┌─────────────────┐
│  Route-Switcher │    │   Primary Router│    │   ICMP Target   │
│                 │    │                 │    │                 │
│ eth0 ────────────┼────►│ eth0 ──────────┼────►│  192.168.202.100│
│ eth1 ────────────┼────►│ eth1 ──────────┼────►│                 │
└─────────────────┘    └─────────────────┘    └─────────────────┘
```

### Container Setup
- **route-switcher**: Dual interfaces (eth0→primary-net, eth1→secondary-net)
- **primary-router**: Connects primary-net ↔ target-net (192.168.200.11 ↔ 192.168.202.11)
- **secondary-router**: Connects secondary-net ↔ target-net (192.168.201.11 ↔ 192.168.202.12)
- **icmp-target**: Single IP on target-net (192.168.202.100)

## Test Scenarios

### 1. Basic Connectivity Test
```bash
podman-compose up -d
podman-compose exec route-switcher ping -c 3 -I eth0 192.168.202.100
podman-compose exec route-switcher ping -c 3 -I eth1 192.168.202.100
```

### 2. Failover Test
```bash
# Monitor logs
podman-compose logs -f route-switcher &

# Simulate primary router failure
podman-compose exec primary-router ip link set eth0 down

# Verify failover occurs and connectivity works
podman-compose exec route-switcher ping -c 3 192.168.202.100

# Restore primary router
podman-compose exec primary-router ip link set eth0 up

# Verify failback after 60 seconds
```

### 3. Dual Failure Test
```bash
# Fail both routers - system should NOT switch
podman-compose exec primary-router ip link set eth0 down
podman-compose exec secondary-router ip link set eth0 down

# Verify no routing changes occur
```

## Automated Testing

Run the comprehensive test script:
```bash
./scripts/test-failover.sh
```

This script:
1. Starts the test environment
2. Verifies initial connectivity
3. Simulates primary router failure
4. Monitors failover
5. Restores primary router
6. Verifies failback

## Unit Tests

```bash
# Run all tests
cargo test

# Run specific module
cargo test pinger
cargo test routing
cargo test state_machine
```

## Debug Commands

```bash
# Check container interfaces
podman-compose exec route-switcher ip addr show

# Check routing table
podman-compose exec route-switcher ip route show

# Monitor network traffic
podman-compose exec route-switcher tcpdump -i any icmp
```