add new test

Author: mkovaxx

tests/default_output_pattern.rs

@@ -0,0 +1,17 @@
+use anodized::contract;
+
+#[contract(
+    returns: (a, b),
+    ensures: a <= b,
+    ensures: (a, b) == pair || (b, a) == pair,
+)]
+fn sort_pair(pair: (i32, i32)) -> (i32, i32) {
+    // Deliberately wrong implementation to break the contract.
+    pair
+}
+
+#[test]
+#[should_panic(expected = "Postcondition failed: a <= b")]
+fn test_sort_fail_postcondition() {
+    sort_pair((5, 2));
+}