adds encap decap test

src/tests/kem.rs

@@ -0,0 +1,25 @@
+#![allow(warnings)]
+#[cfg(test)]
+mod kem_tests {
+    use crate::kem::*;
+    use proptest::prelude::*;
+
+    prop_compse! {
+        fn new_keypair()
+            (k in 2..=4)
+            -> (PublicKey, PrivateKey) {
+                generate_key_pair(None, k).unwrap()
+            }
+    }
+
+    proptest! {
+        #[test]
+        fn encapsulate_decapsulate((pk, sk) in new_keypair()) {
+            let (ciphertext, shared_secret) = pk.encapsulate().unwrap();
+
+            let decap_secret = sk.decapsulate(ciphertext).unwrap();
+
+            assert_eq!(shared_secret, decap_secret);
+        }
+    }
+}