undocumented

.undocumented() takes the schemas of one manual registration out of the document and lifts its JsonSchema demand.

Under the asyncapi feature a subscriber(..) registration is documented by default. Mounting it demands JsonSchema of its message types, and a type without the derive is a compile error at the mount. undocumented is the exit for one registration, such as one whose message type comes from a crate that ships no schema. The registration stays in the document: its channel and its operation remain, and its messages carry no payload schema. messages_without_schema lists those messages. The step is written once; a second one does not compile. On the attribute path a type without the derive already mounts and contributes no schema, so the attribute has no such step. Without the asyncapi feature a registration demands nothing. The example runs with cargo test --example asyncapi_schemas --features macros,memory,asyncapi.

Example

Macros

examples/asyncapi_schemas.rs

/// An audit record another team publishes, with no schema shipped for it.
#[derive(Debug, Deserialize)]
struct AuditRecord {
    action: String,
}

#[subscriber("audit")]
async fn record(entry: &AuditRecord) -> HandlerOutcome {
    tracing::info!(action = %entry.action, "audited");
    HandlerOutcome::ack()
}

Manual

examples/manual/asyncapi_schemas.rs

fn app() -> impl App {
    RustStream::new(AppInfo::new("orders", "0.1.0")).with_broker(MemoryBroker::new(), |b| {
        b.include(subscriber("orders", Accept).build());
        b.include(subscriber("refunds", Refund).build());
        // `AuditRecord` has no `JsonSchema`: without this step the mount does not compile.
        b.include(subscriber("audit", Record).undocumented().build());
    })
}