notescraft/crates/acp/tests/protocol_flow.rs

//! Happy-path ACP flow tests: exact event order, permission round trip,
//! cancel — against the stub agent.

mod common;

use std::time::Duration;

use common::{collect_until, handshake, next_event, spawn_stub};
use notescraft_acp::{Event, PromptBlock, RequestId, SessionUpdate, ToolCallInfo};

const TIMEOUT: Duration = Duration::from_secs(15);

#[test]
fn happy_path_event_order_and_permission_answer() {
    let process = spawn_stub("normal");
    let session_id = handshake(&process);
    process.prompt(&session_id, &[PromptBlock::Text("hello agent".to_string())]).unwrap_or_else(|e| panic!("prompt failed: {e}"));

    // Drain until the turn ends, answering the permission request in-flight:
    // the stub waits for our answer before it sends the ack and the turn end.
    let first = collect_until(process.events(), TIMEOUT, |event| matches!(event, Event::PermissionRequest { .. }));
    for event in &first {
        if let Event::PermissionRequest { request_id, options, .. } = event {
            let allowed = options.first().map(|option| option.id.clone()).unwrap_or_default();
            process.answer_permission(request_id, Some(&allowed)).unwrap_or_else(|e| panic!("answer_permission failed: {e}"));
        }
    }
    let rest = collect_until(process.events(), TIMEOUT, |event| matches!(event, Event::PromptDone { .. }));
    let mut all = first;
    all.extend(rest);
    assert!(matches!(all.last(), Some(Event::PromptDone { .. })), "expected prompt done: {all:?}");

    // Exact expected order.
    let expected: Vec<String> = [
        "chunk:Hello ",
        "chunk:world",
        "tool_call:t1:pending",
        "tool_call_update:t1:completed",
        "permission_request:perm-1",
        "ack:allow",
        "prompt_done:end_turn",
    ]
    .iter()
    .map(ToString::to_string)
    .collect();
    assert_eq!(described(&all), expected, "event order mismatch: {all:?}");

    // Tool call details.
    let Some(Event::Update(SessionUpdate::ToolCall(info))) = all.iter().find(|e| matches!(e, Event::Update(SessionUpdate::ToolCall(_)))) else {
        panic!("missing tool call event");
    };
    assert_eq!(info.id, "t1");
    assert_eq!(info.kind, "read");
    assert_eq!(info.locations.first().map(String::as_str), Some("notes/a.md"));
    assert!(info.raw_input.is_some());
}

fn described(events: &[Event]) -> Vec<String> {
    events
        .iter()
        .filter_map(|event| match event {
            Event::Update(SessionUpdate::AgentMessageChunk(text)) => Some(format!("chunk:{text}")),
            Event::Update(SessionUpdate::ToolCall(info)) => Some(format!("tool_call:{}:{}", info.id, info.status)),
            Event::Update(SessionUpdate::ToolCallUpdate { id, status, .. }) => Some(format!("tool_call_update:{}:{}", id, status.clone().unwrap_or_default())),
            Event::Update(SessionUpdate::Other(value)) => Some(format!("ack:{}", value.get("optionId").and_then(serde_json::Value::as_str).unwrap_or("?"))),
            Event::PermissionRequest { request_id, .. } => match request_id {
                RequestId::Text(name) => Some(format!("permission_request:{name}")),
                RequestId::Number(n) => Some(format!("permission_request:#{n}")),
            },
            Event::PromptDone { stop_reason } => Some(format!("prompt_done:{stop_reason}")),
            _ => None,
        })
        .collect()
}

#[test]
fn cancelled_turn_reports_stop_reason() {
    let process = spawn_stub("cancel");
    let session_id = handshake(&process);
    process.prompt(&session_id, &[PromptBlock::Text("long task".to_string())]).unwrap_or_else(|e| panic!("prompt failed: {e}"));
    // Give the stub a moment to see the prompt, then cancel.
    std::thread::sleep(Duration::from_millis(200));
    process.cancel(&session_id).unwrap_or_else(|e| panic!("cancel failed: {e}"));

    let all = collect_until(process.events(), TIMEOUT, |event| matches!(event, Event::PromptDone { .. }));
    assert_eq!(described(&all), vec!["chunk:cancelled", "prompt_done:cancelled"]);
}

#[test]
fn permission_cancel_reports_option_none() {
    let process = spawn_stub("normal");
    let session = handshake(&process);
    process.prompt(&session, &[PromptBlock::Text("ask me".to_string())]).unwrap_or_else(|e| panic!("prompt failed: {e}"));

    let mut request_id: Option<RequestId> = None;
    let mut tool_call: Option<ToolCallInfo> = None;
    while request_id.is_none() {
        match next_event(process.events(), TIMEOUT) {
            Event::PermissionRequest { request_id: id, tool_call: call, .. } => {
                request_id = Some(id);
                tool_call = Some(call);
            }
            Event::Exited { .. } => panic!("agent exited before permission round trip"),
            _ => {}
        }
    }
    let Some(request) = request_id.as_ref() else {
        panic!("no permission request id");
    };
    process.answer_permission(request, None).unwrap_or_else(|e| panic!("answer failed: {e}"));

    let Some(call) = tool_call else {
        panic!("permission request missing tool call info");
    };
    assert_eq!(call.id, "t1");
    assert_eq!(call.kind, "edit");

    let all = collect_until(process.events(), TIMEOUT, |event| matches!(event, Event::PromptDone { .. }));
    let acks: Vec<String> = described(&all).into_iter().filter(|text| text.starts_with("ack:")).collect();
    assert_eq!(acks, vec!["ack:cancelled"]);
}