switchyard_libsy/algorithms/
noop.rs

1// SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
2// SPDX-License-Identifier: Apache-2.0
3
4//! Test-only algorithm that returns a hard-coded response without calling a backend.
5
6use std::sync::Arc;
7
8use switchyard_protocol::{
9    AggLlmResponse, ContentBlock, LlmResponse, Request, Response, ResponseOutput, Role, StopReason,
10};
11
12use crate::Result;
13use crate::core::algorithm::{Algorithm, Driver};
14use switchyard_protocol::Decision;
15
16/// Test helper that returns a hard-coded response without routing or model I/O.
17pub struct Noop {}
18
19#[async_trait::async_trait]
20impl Algorithm for Noop {
21    fn name(&self) -> &str {
22        "noop"
23    }
24
25    async fn create_run_task(
26        self: Arc<Self>,
27        driver: Driver,
28        request: Request,
29    ) -> Result<Response> {
30        let model = request
31            .requested_model()
32            .unwrap_or("switchyard/noop")
33            .to_string();
34        let decision: Decision = Decision::new(
35            model.clone(),
36            Some("noop returned its synthetic response".to_string()),
37            true,
38        );
39        driver.info(decision.clone()).await?;
40
41        let llm_response = LlmResponse::Agg(AggLlmResponse {
42            id: Some("switchyard-noop".to_string()),
43            model: Some(model),
44            outputs: vec![ResponseOutput {
45                role: Role::Assistant,
46                content: vec![ContentBlock::Text {
47                    text: "OK".to_string(),
48                }],
49                stop_reason: Some(StopReason::EndTurn),
50            }],
51            ..Default::default()
52        });
53        let response = Response {
54            llm_response,
55            metadata: request.metadata.clone(),
56        };
57        Ok(response)
58    }
59}
60
61#[cfg(test)]
62mod tests {
63    use switchyard_protocol::{LlmRequest, Message, Role};
64
65    use super::*;
66    use crate::core::testing::{echo, test_drive};
67
68    #[tokio::test]
69    async fn test_noop_algo() -> Result<()> {
70        const TEST_MODEL: &str = "test_noop_algo";
71        let request = Request {
72            llm_request: LlmRequest {
73                model: Some(TEST_MODEL.to_string()),
74                messages: vec![Message::text(Role::User, "hi")],
75                ..LlmRequest::default()
76            },
77            raw_request: None,
78            metadata: None,
79        };
80
81        // `Noop` synthesizes its own response and never offloads a call, so `echo` is
82        // never reached.
83        let a: Arc<dyn Algorithm> = Arc::new(Noop {});
84        let (decisions, response) = test_drive(a, request, echo()).await?;
85        let Some(decision) = decisions.first() else {
86            panic!("Expected exactly one Decision");
87        };
88        assert_eq!(decision.selected_model_id(), TEST_MODEL);
89        assert!(decision.is_answer_call());
90        assert_eq!(response.selected_model(), Some(TEST_MODEL));
91        Ok(())
92    }
93}
switchyard_libsy/algorithms/noop.rs

switchyard_libsy/algorithms/
noop.rs
