Response typing

Fluxzero allows you to formalize the expected return type of commands and queries by implementing the Request<R> interface. This lets the framework:

Infer the response type at runtime and during testing
Validate handler methods at compile-time (e.g., @HandleQuery must return an R)
Simplify queryAndWait(...) or sendCommand(...) invocations

Here’s an example for a query:

Java
Kotlin

@Value
public class GetUserProfile implements Request<UserProfile> {
    String userId;

    @HandleQuery
    UserProfile handle() {
        return loadProfile(userId);
    }
}

data class GetUserProfile(val userId: String) : Request<UserProfile> {

    @HandleQuery
    fun handle(): UserProfile {
        return loadProfile(userId)
    }
}

Now, when calling this query, the return type is automatically known:

Java
Kotlin

UserProfile profile = Fluxzero.queryAndWait(new GetUserProfile("123"));

val profile = Fluxzero.queryAndWait(GetUserProfile("123"))

When implementing Request<R>, the expected result type (R) is automatically inferred during testing and execution. This enables type-safe tests like:

Java
Kotlin

testFixture.whenQuery(new GetUserProfile("123"))
        .expectResult(profile -> profile.getUserId().equals("123"));

testFixture.whenQuery(GetUserProfile("123"))
        .expectResult { it.userId == "123" }

If a class implements Request<R>, Fluxzero will use its declared generic type (R) to check that:

A compatible handler exists
The handler returns the correct result type
The correct response is expected during testing