crypto: Test for plain JSON and typed deserialization

crates/matrix-sdk-crypto/src/olm/session.rs

@@ -289,7 +289,7 @@ mod tests {
     use assert_matches2::assert_let;
     use matrix_sdk_test::async_test;
     use ruma::{device_id, user_id};
-    use serde_json;
+    use serde_json::{self, Value};
     use vodozemac::olm::{OlmMessage, SessionConfig};
 
     use crate::{
@@ -352,9 +352,16 @@ mod tests {
             )
             .unwrap();
 
-        // Also ensure that the encrypted payload has the device keys.
-        let plaintext: DecryptedOlmV1Event<DummyEventContent> =
+        // Also ensure that the encrypted payload has the device keys under the unstable prefix
+        let plaintext: Value = serde_json::from_str(&bob_session_result.plaintext).unwrap();
+        assert_eq!(
+            plaintext["org.matrix.msc4147.device_keys"]["user_id"].as_str(),
+            Some("@alice:localhost")
+        );
+
+        // And the serialized object matches the format as specified in DecryptedOlmV1Event
+        let event: DecryptedOlmV1Event<DummyEventContent> =
             serde_json::from_str(&bob_session_result.plaintext).unwrap();
-        assert_eq!(plaintext.device_keys.unwrap(), alice.device_keys());
+        assert_eq!(event.device_keys.unwrap(), alice.device_keys());
     }
 }