add test for returning tuples from function

compiler/tests/function/mod.rs

@@ -174,3 +174,13 @@ fn test_return_array_tuple_pass() {
 
     assert_satisfied(program);
 }
+
+// Test return tuples
+
+#[test]
+fn test_return_tuple() {
+    let bytes = include_bytes!("return_tuple.leo");
+    let program = parse_program(bytes).unwrap();
+
+    assert_satisfied(program);
+}

compiler/tests/function/return_tuple.leo

@@ -0,0 +1,11 @@
+// Returns a tuple of tuples.
+function tuples() -> ((u8, u8), u32) {
+    let a: (u8, u8) = (1, 2);
+    let b: u32 = 3;
+
+    return (a, b)
+}
+
+function main() {
+    let t = tuples();
+}