# 🧪 Testing with Hylix
> Write, run, and automate tests for your vApp with confidence.
## 📦 Types of Tests
Hylix supports two main layers of testing:
| **Unit tests** | Contract or backend logic in isolation | `cargo test` |
| **E2E tests** | Full vApp workflow with local chain, provers, backend | `hy test` + local devnet |
## ✅ Writing Contract Unit Tests
Unit tests live in your vApp's crate (e.g. `contracts/mycontract/src/`) and use normal Rust testing.
Example:
```rust
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_addition() {
assert_eq!(add(2, 2), 4);
}
}
```
Run only unit tests:
```bash
cargo test
```
You can also add tests to your backend (`server/src`).
## 🧪 Writing E2E Tests
End-to-end tests live in the `tests/` folder at the root of your project.
They allow you to validate:
- Contract registration
- Proof generation & verification
- Interaction with a local chain
- Backend & API behavior
Example file: `tests/e2e.rs`
```rust
#[test]
fn test_end_to_end_proof_verification() {
// 1. Setup client
// 2. Deploy the contract
// 3. Send proof or call method
// 4. Assert chain state
}
```
Use:
- [`Hyli client SDK`](https://crates.io/crates/hyli-client-sdk) to interact with the node / indexer
- Coming soon: `Hyli testing SDK` for helpers like registering accounts or sending tokens
## 🚀 Running Tests
Run all tests in an orchestrated environment:
```bash
hy test
```
This will:
1. Start a local devnet (`hy devnet`) if not already running
1. Compile your project (`hy build`)
1. Launch your backend (`hy run`)
1. Run tests in tests / via `cargo test`
1. Shut down the devnet and backend after completion
## 🔁 [Optional] Persistent devnet
Keep the devnet alive between test runs for faster iteration:
```bash
hy test --keep-alive
```
## 🧪 Test Fixtures & Helpers
You can define shared setup logic in a `helpers` module or `test_utils.rs`. The Hyli testing SDK gives utilities like:
- account registration
- token transfers
- composing tests with built-in contracts (wallet, tokens)