chore(fhe_strings): add encryption-decryption test

tfhe/examples/fhe_strings/assert_functions/mod.rs

@@ -125,6 +125,17 @@ impl Keys {
         assert_eq!(dec, expected);
     }
 
+    pub fn assert_encrypt_decrypt(&self, str: &str, str_pad: Option<u32>) {
+        let enc_str = FheString::new(&self.ck, str, str_pad);
+
+        let dec = self.ck.decrypt_ascii(&enc_str);
+
+        println!("\n\x1b[1mEncrypt/Decrypt:\x1b[0m");
+        result_message(str, str, &dec, Duration::from_nanos(0));
+
+        assert_eq!(str, &dec);
+    }
+
     pub fn assert_contains(
         &self,
         str: &str,

tfhe/examples/fhe_strings/assert_functions/test_vectors.rs

@@ -140,6 +140,15 @@ fn test_is_empty() {
     }
 }
 
+#[test]
+fn test_encrypt_decrypt() {
+    let keys = Keys::new();
+
+    for (str, str_pad) in TEST_CASES_MATCH {
+        keys.assert_encrypt_decrypt(str, Some(str_pad));
+    }
+}
+
 #[test]
 fn test_contains() {
     let keys = Keys::new();

tfhe/examples/fhe_strings/main.rs

@@ -105,6 +105,8 @@ fn main() {
     keys.assert_len(str, str_pad);
     keys.assert_is_empty(str, str_pad);
 
+    keys.assert_encrypt_decrypt(str, str_pad);
+
     keys.assert_contains(str, str_pad, pat, pat_pad);
     keys.assert_ends_with(str, str_pad, pat, pat_pad);
     keys.assert_starts_with(str, str_pad, pat, pat_pad);