Add tests for UDTs with tuple fields.

Closes stellar#1124

tests/udt/src/lib.rs

@@ -1,6 +1,8 @@
 #![no_std]
 use soroban_sdk::{contract, contractimpl, contracttype, Vec};
 
+mod tuples;
+
 #[contracttype]
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub enum UdtEnum2 {

tests/udt/src/tuples.rs

@@ -0,0 +1,53 @@
+use soroban_sdk::{contract, contractimpl, contracttype, Address, Vec};
+
+#[contracttype]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub enum UdtEnum {
+    UdtA((u32, Address)),
+}
+
+#[contracttype]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct UdtTuple((u32, Address));
+
+#[contracttype]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct UdtStruct {
+    f1: (u32, Address),
+}
+
+#[contract]
+pub struct Contract;
+
+#[contractimpl]
+impl Contract {
+    pub fn id(v: (UdtEnum, UdtTuple, UdtStruct)) -> (UdtEnum, UdtTuple, UdtStruct) {
+        (v.0, v.1, v.2)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use soroban_sdk::testutils::Address as _;
+    use soroban_sdk::{vec, xdr::ScVal, Bytes, Env, TryFromVal};
+
+    #[test]
+    fn test_tuples() {
+        let e = Env::default();
+        let contract_id = e.register_contract(None, Contract);
+        let client = ContractClient::new(&e, &contract_id);
+
+        let v1 = (
+            UdtEnum::UdtA((1, Address::random(&e))),
+            UdtTuple((2, Address::random(&e))),
+            UdtStruct {
+                f1: (3, Address::random(&e)),
+            },
+        );
+
+        let v2 = client.id(&v1);
+
+        assert_eq!(v1, v2);
+    }
+}