mobius 0.16.19

A small, modular Rust framework for building coding agents
Documentation
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use super::super::*;
use super::support::{
    completed_events, read_http_json, write_http_compaction_stream, write_http_stream,
};
use crate::backend::model::PromptCacheIdentity;
use tokio::io::{AsyncReadExt as _, AsyncWriteExt as _};

#[tokio::test]
async fn upgrade_required_switches_only_that_session_to_sticky_http() {
    use futures_util::SinkExt as _;
    use futures_util::StreamExt as _;

    let websocket_listener = tokio::net::TcpListener::bind(("127.0.0.1", 0))
        .await
        .expect("WebSocket listener");
    let websocket_address = websocket_listener.local_addr().expect("WebSocket address");
    let websocket_server = tokio::spawn(async move {
        let (stream, _) = websocket_listener
            .accept()
            .await
            .expect("initial WebSocket connection");
        let mut socket = tokio_tungstenite::accept_async(stream)
            .await
            .expect("initial WebSocket handshake");
        let initial: Value = serde_json::from_slice(
            &socket
                .next()
                .await
                .expect("initial response request")
                .expect("valid initial response request")
                .into_data(),
        )
        .expect("initial response body");
        assert!(initial.get("previous_response_id").is_none());
        assert_eq!(initial["service_tier"], "default");
        for event in completed_events("Warm response.", "response-warm") {
            socket
                .send(Message::text(event.to_string()))
                .await
                .expect("initial completed event");
        }
        let continued: Value = serde_json::from_slice(
            &socket
                .next()
                .await
                .expect("continued response request")
                .expect("valid continued response request")
                .into_data(),
        )
        .expect("continued response body");
        assert_eq!(continued["previous_response_id"], "response-warm");
        assert_eq!(
            continued["input"]
                .as_array()
                .expect("incremental input")
                .len(),
            1
        );
        drop(socket);

        let (mut stream, _) = websocket_listener
            .accept()
            .await
            .expect("fallback WebSocket connection");
        let mut request = Vec::new();
        while !request.windows(4).any(|bytes| bytes == b"\r\n\r\n") {
            let mut chunk = [0; 1_024];
            let count = stream.read(&mut chunk).await.expect("handshake request");
            assert_ne!(count, 0, "request ended before its headers");
            request.extend_from_slice(&chunk[..count]);
        }
        stream
            .write_all(
                b"HTTP/1.1 426 Upgrade Required\r\nContent-Length: 0\r\nConnection: close\r\n\r\n",
            )
            .await
            .expect("fallback handshake response");
    });

    let http_listener = tokio::net::TcpListener::bind(("127.0.0.1", 0))
        .await
        .expect("HTTP listener");
    let http_address = http_listener.local_addr().expect("HTTP address");
    let (request_sender, mut requests) = mpsc::channel(4);
    let http_server = tokio::spawn(async move {
        for attempt in 0..4 {
            let (mut stream, _) = http_listener.accept().await.expect("HTTP connection");
            let request = read_http_json(&mut stream).await;
            request_sender
                .send(request)
                .await
                .expect("captured request");
            if attempt < 2 {
                write_http_stream(
                    &mut stream,
                    if attempt == 0 {
                        "HTTP fallback."
                    } else {
                        "Still HTTP."
                    },
                    &format!("response-http-{attempt}"),
                )
                .await;
            } else if attempt == 2 {
                write_http_compaction_stream(&mut stream).await;
            }
        }
    });

    let socket_url = format!("ws://{websocket_address}/responses");
    let provider = OpenAiSocket::with_authorization(
        Arc::new(ApiKeyAuthorization::new("test-key".into())),
        &format!("http://{http_address}"),
        &socket_url,
        "gpt-6.1-sol",
        reqwest::Client::new(),
        crate::backend::model::ModelTransportSettings::default(),
    )
    .expect("provider")
    .with_service_tier(Some("default".into()))
    .with_reasoning_effort("medium")
    .expect("reasoning effort")
    .with_cached_web_search();
    let directory = tempfile::tempdir().expect("state");
    let files = crate::backend::session_files::SessionFileStore::new(directory.path(), None);
    let mut bytes = std::io::Cursor::new(Vec::new());
    image::DynamicImage::new_rgb8(8, 8)
        .write_to(&mut bytes, image::ImageFormat::Png)
        .expect("PNG");
    let image = files
        .ingest_image(
            "fallback-session",
            "image.png".into(),
            bytes.into_inner(),
            crate::protocol::ImageDetail::High,
        )
        .await
        .expect("image");
    let media = crate::backend::model::MediaPreparation {
        files: Some(&files),
        limits: crate::backend::model::ImageInputLimits::default(),
    };
    let input = vec![serde_json::json!({
        "role": "user",
        "content": [{"type": "input_text", "text": "hello"}, {"type":"input_image", "image":image}]
    })];
    let events: ModelEventSink = Arc::new(|_| Box::pin(async { Ok(()) }));

    let warm = provider
        .respond_prepared(
            ModelRequest {
                session_id: "fallback-session",
                prompt_cache: Some(PromptCacheIdentity {
                    key: "hashed-fallback-session",
                    context_epoch: 1,
                }),
                instructions: "Test instructions",
                input: &input,
                catalog_revision: "catalog-1",
                tools: &[],
                deferred_tools: &[],
                allow_hosted_tools: true,
                allow_continuation: true,
            },
            Arc::clone(&events),
            media,
        )
        .await
        .expect("initial WebSocket response");
    let mut continued_input = input.clone();
    continued_input.extend(warm.output().iter().cloned());
    continued_input.push(serde_json::json!({
        "role": "user",
        "content": [{"type": "input_text", "text": "continue"}]
    }));

    let Error::Provider(error) = provider
        .respond_prepared(
            ModelRequest {
                session_id: "fallback-session",
                prompt_cache: Some(PromptCacheIdentity {
                    key: "hashed-fallback-session",
                    context_epoch: 1,
                }),
                instructions: "Test instructions",
                input: &continued_input,
                catalog_revision: "catalog-1",
                tools: &[],
                deferred_tools: &[],
                allow_hosted_tools: true,
                allow_continuation: true,
            },
            Arc::clone(&events),
            media,
        )
        .await
        .expect_err("closed WebSocket should be retried before fallback")
    else {
        panic!("expected provider error");
    };
    assert!(error.is_stream_interrupted());

    let fallback = provider
        .respond_prepared(
            ModelRequest {
                session_id: "fallback-session",
                prompt_cache: Some(PromptCacheIdentity {
                    key: "hashed-fallback-session",
                    context_epoch: 1,
                }),
                instructions: "Test instructions",
                input: &continued_input,
                catalog_revision: "catalog-1",
                tools: &[],
                deferred_tools: &[],
                allow_hosted_tools: true,
                allow_continuation: true,
            },
            Arc::clone(&events),
            media,
        )
        .await
        .expect("HTTP fallback");
    let sticky = provider
        .respond_prepared(
            ModelRequest {
                session_id: "fallback-session",
                prompt_cache: Some(PromptCacheIdentity {
                    key: "hashed-fallback-session",
                    context_epoch: 1,
                }),
                instructions: "Test instructions",
                input: &continued_input,
                catalog_revision: "catalog-1",
                tools: &[],
                deferred_tools: &[],
                allow_hosted_tools: true,
                allow_continuation: true,
            },
            Arc::clone(&events),
            media,
        )
        .await
        .expect("sticky HTTP fallback");
    let compacted = provider
        .compact_prepared(
            CompactRequest {
                session_id: "fallback-session",
                prompt_cache: Some(PromptCacheIdentity {
                    key: "hashed-fallback-session",
                    context_epoch: 1,
                }),
                instructions: "Test instructions",
                input: &continued_input,
                catalog_revision: "catalog-1",
                tools: &[],
                deferred_tools: &[],
            },
            media,
        )
        .await
        .expect("HTTP v2 compaction");
    let Error::Provider(http_error) = provider
        .respond_prepared(
            ModelRequest {
                session_id: "fallback-session",
                prompt_cache: Some(PromptCacheIdentity {
                    key: "hashed-fallback-session",
                    context_epoch: 1,
                }),
                instructions: "Test instructions",
                input: &continued_input,
                catalog_revision: "catalog-1",
                tools: &[],
                deferred_tools: &[],
                allow_hosted_tools: true,
                allow_continuation: true,
            },
            Arc::clone(&events),
            media,
        )
        .await
        .expect_err("HTTPS failure should remain retryable after fallback")
    else {
        panic!("expected provider error");
    };
    let first_http = requests.recv().await.expect("first HTTP request");
    let second_http = requests.recv().await.expect("second HTTP request");
    let compact_http = requests.recv().await.expect("compaction HTTP request");
    let failed_http = requests.recv().await.expect("failed HTTP request");
    http_server.await.expect("HTTP server");
    websocket_server.await.expect("WebSocket server");

    assert_eq!(fallback.text(), "HTTP fallback.");
    assert_eq!(sticky.text(), "Still HTTP.");
    assert_eq!(
        compacted.output(),
        &[serde_json::json!({
            "type": "compaction",
            "encrypted_content": "opaque"
        })]
    );
    assert_eq!(http_error.status(), None);
    assert!(http_error.is_stream_interrupted());
    assert_eq!(
        http_error.to_string(),
        "model response stream was interrupted"
    );
    for request in [first_http, second_http, failed_http] {
        assert!(
            request["input"][0]["content"][1]["image_url"]
                .as_str()
                .expect("replayed image")
                .starts_with("data:image/jpeg;base64,")
        );
        assert_eq!(request["service_tier"], "default");
        assert!(request.get("previous_response_id").is_none());
        assert_eq!(
            request["input"].as_array().expect("full HTTP input").len(),
            continued_input.len()
        );
        assert_eq!(
            request["reasoning"],
            serde_json::json!({"effort": "medium", "summary": "auto"})
        );
        assert_eq!(
            request["tools"],
            serde_json::json!([{"type": "web_search", "external_web_access": false}])
        );
    }
    assert!(compact_http.get("previous_response_id").is_none());
    let compact_input = compact_http["input"]
        .as_array()
        .expect("full HTTP compaction input");
    assert_eq!(compact_input.len(), continued_input.len() + 1);
    assert!(compact_input[0]["content"][1]["image_url"].is_string());
    assert_eq!(
        compact_input.last(),
        Some(&serde_json::json!({"type": "compaction_trigger"}))
    );
}

#[tokio::test]
async fn explicit_fallback_is_sticky_and_isolated_to_the_session() {
    let listener = tokio::net::TcpListener::bind(("127.0.0.1", 0))
        .await
        .expect("listener");
    let address = listener.local_addr().expect("address");
    let server = tokio::spawn(async move {
        for attempt in 0..2 {
            let (mut stream, _) = listener.accept().await.expect("HTTP connection");
            let request = read_http_json(&mut stream).await;
            assert!(request.get("previous_response_id").is_none());
            assert_eq!(request["input"][0]["content"], "complete history");
            write_http_stream(&mut stream, "Recovered.", &format!("http-{attempt}")).await;
        }
    });
    let provider = OpenAiSocket::with_authorization(
        Arc::new(ApiKeyAuthorization::new("test-key".into())),
        &format!("http://{address}"),
        "ws://127.0.0.1:1",
        "test-model",
        reqwest::Client::new(),
        crate::backend::model::ModelTransportSettings::default(),
    )
    .expect("provider");
    assert!(
        provider
            .fallback_transport("fallback")
            .await
            .expect("switch")
    );
    assert!(
        !provider
            .fallback_transport("fallback")
            .await
            .expect("already switched")
    );
    assert!(
        !provider
            .session("other")
            .await
            .expect("other session")
            .lock()
            .await
            .use_http
    );
    let input = [serde_json::json!({"role": "user", "content": "complete history"})];
    for _ in 0..2 {
        let output = provider
            .respond(
                ModelRequest {
                    session_id: "fallback",
                    input: &input,
                    allow_continuation: true,
                    ..super::support::model_request()
                },
                Arc::new(|_| Box::pin(async { Ok(()) })),
            )
            .await
            .expect("HTTP response");
        assert_eq!(output.text(), "Recovered.");
    }
    server.await.expect("server");
}