test: Add test for info string construction.

src/ecies/mod.rs

@@ -691,6 +691,37 @@ mod test {
         assert_eq!(digit, 55, "u8::MAX should generate 55");
     }
 
+    #[test]
+    fn test_info_construction() {
+        use crate::types::Curve25519Keypair;
+
+        let app_info = "foobar";
+        let our_public_key = Curve25519Keypair::new().public_key;
+        let their_public_key = Curve25519Keypair::new().public_key;
+
+        let check_code_info1 = EstablishedEcies::get_check_code_info(
+            app_info,
+            Role::Initiator,
+            our_public_key,
+            their_public_key,
+        );
+        assert_eq!(
+            check_code_info1,
+            format!("foobar_CHECKCODE|{their_public_key}|{our_public_key}")
+        );
+
+        let check_code_info2 = EstablishedEcies::get_check_code_info(
+            app_info,
+            Role::Recipient,
+            our_public_key,
+            their_public_key,
+        );
+        assert_eq!(
+            check_code_info2,
+            format!("foobar_CHECKCODE|{our_public_key}|{their_public_key}")
+        );
+    }
+
     proptest! {
         #[test]
         fn check_code_proptest(bytes in prop::array::uniform2(0u8..) ) {