Function synthesize_subagent_progress

core/src/tools/task.rs:107–149

Translate selected child-loop events into a `SubagentProgress` milestone for the parent broadcast. Returns `None` for events that aren't worth surfacing as progress (text deltas, tool starts, subagent events from nested delegation, etc.). Currently emits progress for: - `ToolEnd` → `status = "tool_completed"`, `metadata = { tool, exit_code, output_bytes, error_kind? }` - `TurnEnd` → `status =

(
    event: &AgentEvent,
    task_id: &str,
    session_id: &str,
)

/// - `TurnEnd`   → `status = "turn_completed"`,
///   `metadata = { turn, total_tokens, prompt_tokens, completion_tokens }`
fn synthesize_subagent_progress(
    event: &AgentEvent,
    task_id: &str,
    session_id: &str,
) -> Option<AgentEvent> {
    match event {
        AgentEvent::ToolEnd {
            name,
            output,
            exit_code,
            error_kind,
            ..
        } => {
            let mut metadata = serde_json::json!({
                "tool": name,
                "exit_code": exit_code,
                "output_bytes": output.len(),
            });
            if let Some(kind) = error_kind {
                metadata["error_kind"] =
                    serde_json::to_value(kind).unwrap_or(serde_json::Value::Null);
            }
            Some(AgentEvent::SubagentProgress {
                task_id: task_id.to_string(),
                session_id: session_id.to_string(),
                status: "tool_completed".to_string(),
                metadata,
            })
        }
        AgentEvent::TurnEnd { turn, usage } => Some(AgentEvent::SubagentProgress {
            task_id: task_id.to_string(),
            session_id: session_id.to_string(),
            status: "turn_completed".to_string(),
            metadata: serde_json::json!({
                "turn": turn,
                "total_tokens": usage.total_tokens,
                "prompt_tokens": usage.prompt_tokens,
                "completion_tokens": usage.completion_tokens,
            }),
        }),
        _ => None,
    }
}

fn task_artifact_id(result: &TaskResult) -> String {
    format!("task-output:{}", result.task_id)