add happy_path_alice_does_not_send_transfer_proof integration test

Author: binarybaron

.github/workflows/ci.yml

@@ -180,6 +180,8 @@ jobs:
             test_name: alice_empty_balance_after_started_btc_early_refund
           - package: swap
             test_name: alice_broken_wallet_rpc_after_started_btc_early_refund
+          - package: swap
+            test_name: happy_path_alice_does_not_send_transfer_proof
           - package: monero-tests
             test_name: reserve_proof
           - package: monero-tests

swap/tests/happy_path_alice_does_not_send_transfer_proof.rs

@@ -0,0 +1,63 @@
+pub mod harness;
+
+use harness::alice_run_until::is_xmr_lock_transaction_sent;
+use harness::bob_run_until::is_xmr_locked;
+use harness::SlowCancelConfig;
+use swap::asb::FixedRate;
+use swap::protocol::alice::AliceState;
+use swap::protocol::bob::BobState;
+use swap::protocol::{alice, bob};
+
+/// Test that Bob can detect the Monero lock transaction using the view key
+/// even when Alice goes offline and doesn't send the transfer proof.
+#[tokio::test]
+async fn given_alice_goes_offline_after_xmr_locked_bob_detects_xmr_via_view_key() {
+    harness::setup_test(SlowCancelConfig, None, |mut ctx| async move {
+        // Bob runs until he detects the Monero as having been locked
+        let (bob_swap, bob_join_handle) = ctx.bob_swap().await;
+        let bob_swap_id = bob_swap.id;
+        let bob_swap = tokio::spawn(bob::run_until(bob_swap, is_xmr_locked));
+
+        // Alice runs until the locks the Monero but before she sends the transfer proof
+        let alice_swap = ctx.alice_next_swap().await;
+        let alice_swap = tokio::spawn(alice::run_until(
+            alice_swap,
+            is_xmr_lock_transaction_sent,
+            FixedRate::default(),
+        ));
+
+        // Assert that Alice is in correct state
+        let alice_state = alice_swap.await??;
+        assert!(matches!(
+            alice_state,
+            AliceState::XmrLockTransactionSent { .. }
+        ));
+
+        // Assert that Bob is in correct state
+        let bob_state = bob_swap.await??;
+        assert!(
+            matches!(bob_state, BobState::XmrLocked(..)),
+            "Bob should have detected XMR lock via view key, but state is: {:?}",
+            bob_state
+        );
+
+        // Resume the swap
+        ctx.restart_alice().await;
+        let alice_swap = ctx.alice_next_swap().await;
+        let alice_swap = tokio::spawn(alice::run(alice_swap, FixedRate::default()));
+
+        let (bob_swap, _) = ctx
+            .stop_and_resume_bob_from_db(bob_join_handle, bob_swap_id)
+            .await;
+
+        // Run the swap to completion
+        let bob_state = bob::run(bob_swap).await?;
+        ctx.assert_bob_redeemed(bob_state).await;
+
+        let alice_state = alice_swap.await??;
+        ctx.assert_alice_redeemed(alice_state).await;
+
+        Ok(())
+    })
+    .await;
+}