Introduce test where alice restarts before all communications are done

swap/tests/alice_safe_restart.rs

@@ -263,3 +263,154 @@ async fn given_alice_restarts_after_encsig_is_learned_resume_swap() {
     assert!(xmr_alice_final <= init_xmr_alice - xmr_to_swap);
     assert_eq!(xmr_bob_final, init_xmr_bob + xmr_to_swap);
 }
+
+#[tokio::test]
+async fn given_alice_restarts_after_xmr_is_locked_refund_swap() {
+    setup_tracing();
+
+    let alice_multiaddr: Multiaddr = "/ip4/127.0.0.1/tcp/9876"
+        .parse()
+        .expect("failed to parse Alice's address");
+
+    let btc_to_swap = bitcoin::Amount::from_sat(1_000_000);
+    let init_btc_alice = bitcoin::Amount::ZERO;
+    let init_btc_bob = btc_to_swap * 10;
+
+    let xmr_to_swap = monero::Amount::from_piconero(1_000_000_000_000);
+    let init_xmr_alice = xmr_to_swap * 10;
+    let init_xmr_bob = monero::Amount::ZERO;
+
+    let cli = Cli::default();
+    let (alice_btc_wallet, alice_xmr_wallet, bob_btc_wallet, bob_xmr_wallet, _containers) =
+        setup_wallets(
+            &cli,
+            init_btc_alice,
+            init_xmr_alice,
+            init_btc_bob,
+            init_xmr_bob,
+        )
+        .await;
+
+    let alice_btc_wallet = Arc::new(alice_btc_wallet);
+    let alice_xmr_wallet = Arc::new(alice_xmr_wallet);
+    let bob_btc_wallet = Arc::new(bob_btc_wallet);
+    let bob_xmr_wallet = Arc::new(bob_xmr_wallet);
+
+    let amounts = SwapAmounts {
+        btc: btc_to_swap,
+        xmr: xmr_to_swap,
+    };
+
+    let alice_db_dir = TempDir::new().unwrap();
+    let alice_swap = async {
+        let rng = &mut OsRng;
+        let behaviour = alice::Behaviour::default();
+        let transport = build(behaviour.identity()).unwrap();
+        let start_state = {
+            let a = bitcoin::SecretKey::new_random(rng);
+            let s_a = cross_curve_dleq::Scalar::random(rng);
+            let v_a = xmr_btc::monero::PrivateViewKey::new_random(rng);
+            AliceState::Started {
+                amounts,
+                a,
+                s_a,
+                v_a,
+            }
+        };
+        let config = xmr_btc::config::Config::regtest();
+        let swap_id = Uuid::new_v4();
+
+        let swarm = alice::new_swarm(alice_multiaddr.clone(), transport, behaviour).unwrap();
+        let db = Database::open(alice_db_dir.path()).unwrap();
+
+        // Alice reaches encsig_learned
+        alice::swap::run_until(
+            start_state,
+            |state| matches!(state, AliceState::XmrLocked { .. }),
+            swarm,
+            alice_btc_wallet.clone(),
+            alice_xmr_wallet.clone(),
+            config,
+            swap_id,
+            db,
+        )
+        .await
+        .unwrap();
+
+        let behaviour = alice::Behaviour::default();
+        let transport = build(behaviour.identity()).unwrap();
+        let swarm = alice::new_swarm(alice_multiaddr.clone(), transport, behaviour).unwrap();
+        let db = Database::open(alice_db_dir.path()).unwrap();
+
+        // Load the latest state from the db
+        let latest_state = db.get_state(swap_id).unwrap();
+        let latest_state = latest_state.try_into().unwrap();
+
+        // Finish the swap
+        alice::swap::swap(
+            latest_state,
+            swarm,
+            alice_btc_wallet.clone(),
+            alice_xmr_wallet.clone(),
+            config,
+            swap_id,
+            db,
+        )
+        .await
+    };
+
+    let bob_swap = {
+        let rng = &mut OsRng;
+        let bob_db_dir = tempdir().unwrap();
+        let bob_db = Database::open(bob_db_dir.path()).unwrap();
+        let bob_behaviour = bob::Behaviour::default();
+        let bob_transport = build(bob_behaviour.identity()).unwrap();
+
+        let refund_address = bob_btc_wallet.new_address().await.unwrap();
+        let state0 = xmr_btc::bob::State0::new(
+            rng,
+            btc_to_swap,
+            xmr_to_swap,
+            REFUND_TIMELOCK,
+            PUNISH_TIMELOCK,
+            refund_address,
+        );
+        let bob_state = BobState::Started {
+            state0,
+            amounts,
+            addr: alice_multiaddr.clone(),
+        };
+        let bob_swarm = bob::new_swarm(bob_transport, bob_behaviour).unwrap();
+        bob::swap::swap(
+            bob_state,
+            bob_swarm,
+            bob_db,
+            bob_btc_wallet.clone(),
+            bob_xmr_wallet.clone(),
+            OsRng,
+            Uuid::new_v4(),
+        )
+    };
+
+    try_join(alice_swap, bob_swap).await.unwrap();
+
+    let btc_alice_final = alice_btc_wallet.balance().await.unwrap();
+    let xmr_alice_final = alice_xmr_wallet.get_balance().await.unwrap();
+
+    let btc_bob_final = bob_btc_wallet.balance().await.unwrap();
+    bob_xmr_wallet.0.refresh().await.unwrap();
+    let xmr_bob_final = bob_xmr_wallet.get_balance().await.unwrap();
+
+    // Alice's BTC balance did not change
+    assert_eq!(btc_alice_final, init_btc_alice);
+    // Bob wasted some BTC fees
+    assert_eq!(
+        btc_bob_final,
+        init_btc_bob - bitcoin::Amount::from_sat(bitcoin::TX_FEE)
+    );
+
+    // Alice wasted some XMR fees
+    assert_eq!(init_xmr_alice - xmr_alice_final, monero::Amount::ZERO);
+    // Bob's ZMR balance did not change
+    assert_eq!(xmr_bob_final, init_xmr_bob);
+}