I’m increasing using Rust in addition to Golang to write code. tonic is really excellent but I’d been struggling with coupling its generated types with serde_json because, by default, tonic doesn’t generate types with serde::Serialize annotations.

For what follows, the Protobuf sources are in Google’s googleapis repo, specifically google.firestore.v1.

(JSON) serializing generated types

For example, I’d like to do the following:

use google::firestore::v1::ListenRequest;

async fn mmain() -> Result<(), Box<dyn std::error::Error>> {
    ...
    let rqst = ListenRequest { ... };

    let json_string = serde_json::to_string(&rqst)?;
    dbg!(json_string);
}

Yields: