feat(pool): add deadline guard to swap entrypoint (#107)

contracts/pool/src/lib.rs

@@ -366,9 +366,13 @@ impl NodusAmm {
         to: Address,
         amount_0_out: i128,
         amount_1_out: i128,
+        deadline: u64,
     ) -> Result<(), Error> {
         require_initialized(&env)?;
         require_not_paused(&env)?;
+        if env.ledger().timestamp() > deadline {
+            return Err(Error::Expired);
+        }
         lock(&env)?;
         env.storage()
             .instance()

contracts/pool/tests/integration_tests.rs

@@ -26,15 +26,15 @@ mod integration {
         let (env, contract, _, _) = setup_initialized();
         let client = NodusAmmClient::new(&env, &contract);
         let to = Address::generate(&env);
-        assert!(client.try_swap(&to, &100, &0).is_err());
+        assert!(client.try_swap(&to, &100, &0, &u64::MAX).is_err());
     }
 
     #[test]
     fn swap_zero_output_rejected() {
         let (env, contract, _, _) = setup_initialized();
         let client = NodusAmmClient::new(&env, &contract);
         let to = Address::generate(&env);
-        assert!(client.try_swap(&to, &0, &0).is_err());
+        assert!(client.try_swap(&to, &0, &0, &u64::MAX).is_err());
     }
 
     #[test]
@@ -57,6 +57,15 @@ mod integration {
             .is_err());
     }
 
+    #[test]
+    fn expired_swap_rejected() {
+        let (env, contract, _, _) = setup_initialized();
+        let client = NodusAmmClient::new(&env, &contract);
+        env.ledger().set_timestamp(5_000);
+        let to = Address::generate(&env);
+        assert!(client.try_swap(&to, &100, &0, &1_000).is_err());
+    }
+
     #[test]
     fn not_initialized_token_query_fails() {
         let env = Env::default();
@@ -123,7 +132,7 @@ mod integration {
         client.pause(&admin);
         let to = Address::generate(&env);
         assert_eq!(
-            client.try_swap(&to, &100, &0),
+            client.try_swap(&to, &100, &0, &u64::MAX),
             Err(Ok(nodus_protocol_amm::Error::ContractPaused))
         );
     }
@@ -196,7 +205,7 @@ mod integration {
         let to = Address::generate(&env);
         // No longer blocked by pause; fails for the ordinary reason (no reserves) instead.
         assert_eq!(
-            client.try_swap(&to, &100, &0),
+            client.try_swap(&to, &100, &0, &u64::MAX),
             Err(Ok(nodus_protocol_amm::Error::InsufficientLiquidity))
         );
     }

contracts/pool/tests/unit_tests.rs

@@ -201,7 +201,7 @@ mod soroban_contract_tests {
         let (env, contract) = setup();
         let client = NodusAmmClient::new(&env, &contract);
         let to = Address::generate(&env);
-        assert!(client.try_swap(&to, &100, &0).is_err());
+        assert!(client.try_swap(&to, &100, &0, &u64::MAX).is_err());
     }
 
     #[test]