| 1 | //! Test support: a scriptable in-memory [`WorkflowDriver`]. |
| 2 | //! |
| 3 | //! [`FakeDriver`] records every [`TaskRequest`] and [`ProgressEvent`] it |
| 4 | //! receives, answers spawns from substring-matched reply rules (with optional |
| 5 | //! delays for ordering tests), and counts `cancel_all` calls. It exists so |
| 6 | //! this crate — and the tui wiring that implements the real driver — can be |
| 7 | //! exercised without spawning a single real subagent. |
| 8 | |
| 9 | use std::sync::Mutex; |
| 10 | use std::sync::atomic::{AtomicUsize, Ordering}; |
| 11 | use std::time::Duration; |
| 12 | |
| 13 | use async_trait::async_trait; |
| 14 | use tokio::sync::oneshot; |
| 15 | |
| 16 | use crate::driver::{ |
| 17 | BudgetSnapshot, ProgressEvent, SpawnedTask, TaskCompletion, TaskRequest, WorkflowDriver, |
| 18 | }; |
| 19 | use crate::error::DriverError; |
| 20 | |
| 21 | /// How the fake answers a matched spawn. |
| 22 | #[derive(Debug, Clone)] |
| 23 | pub enum FakeReply { |
| 24 | /// Resolve with this full result text. |
| 25 | Complete(String), |
| 26 | /// Resolve as a failed subagent. |
| 27 | Fail(String), |
| 28 | /// Resolve as cancelled. |
| 29 | Cancelled, |
| 30 | /// Resolve as budget-exhausted mid-flight. |
| 31 | BudgetExhausted(String), |
| 32 | /// Refuse admission: `spawn_task` returns [`DriverError::Rejected`]. |
| 33 | Reject(String), |
| 34 | /// The driver seam is gone: `spawn_task` returns |
| 35 | /// [`DriverError::Unavailable`]. |
| 36 | Unavailable(String), |
| 37 | /// Admit the task, then drop the completion sender without ever sending a |
| 38 | /// terminal outcome — the "driver dropped the completion channel" path. |
| 39 | DropCompletion, |
| 40 | /// Admit the task but never complete it (for cancellation tests). The |
| 41 | /// completion sender is held so the channel stays open. |
| 42 | Never, |
| 43 | /// Never finish admission: `spawn_task` itself stays pending, like a |
| 44 | /// saturated concurrency gate (for cancellation tests). The request is |
| 45 | /// still recorded, so `spawn_count` shows the task reached admission. |
| 46 | HoldAdmission, |
| 47 | } |
| 48 | |
| 49 | #[derive(Debug)] |
| 50 | struct ReplyRule { |
| 51 | needle: String, |
| 52 | delay: Option<Duration>, |
| 53 | reply: FakeReply, |
| 54 | } |
| 55 | |
| 56 | #[derive(Debug, Default)] |
| 57 | struct Inner { |
| 58 | rules: Vec<ReplyRule>, |
| 59 | requests: Vec<TaskRequest>, |
| 60 | events: Vec<ProgressEvent>, |
| 61 | budget: BudgetSnapshot, |
| 62 | spend_per_task: u64, |
| 63 | next_id: u64, |
| 64 | held: Vec<oneshot::Sender<TaskCompletion>>, |
| 65 | } |
| 66 | |
| 67 | /// In-memory [`WorkflowDriver`] with scripted replies. |
| 68 | /// |
| 69 | /// Unmatched spawns complete immediately with `done:<description>`. Rules are |
| 70 | /// matched by substring against the request description, first match wins. |
| 71 | #[derive(Debug, Default)] |
| 72 | pub struct FakeDriver { |
| 73 | inner: Mutex<Inner>, |
| 74 | cancel_calls: AtomicUsize, |
| 75 | } |
| 76 | |
| 77 | impl FakeDriver { |
| 78 | /// A fake with no rules, no budget ceiling, and echo replies. |
| 79 | pub fn new() -> Self { |
| 80 | Self::default() |
| 81 | } |
| 82 | |
| 83 | /// Add a reply rule: requests whose description contains `needle` get |
| 84 | /// `reply` immediately. |
| 85 | pub fn on(&self, needle: &str, reply: FakeReply) { |
| 86 | self.on_with_delay_opt(needle, reply, None); |
| 87 | } |
| 88 | |
| 89 | /// Like [`FakeDriver::on`], but the completion is delivered after `delay` |
| 90 | /// (the spawn itself still returns immediately). |
| 91 | pub fn on_with_delay(&self, needle: &str, reply: FakeReply, delay: Duration) { |
| 92 | self.on_with_delay_opt(needle, reply, Some(delay)); |
| 93 | } |
| 94 | |
| 95 | fn on_with_delay_opt(&self, needle: &str, reply: FakeReply, delay: Option<Duration>) { |
| 96 | self.lock().rules.push(ReplyRule { |
| 97 | needle: needle.to_string(), |
| 98 | delay, |
| 99 | reply, |
| 100 | }); |
| 101 | } |
| 102 | |
| 103 | /// Configure the budget pool: ceiling plus a fixed spend debited at each |
| 104 | /// spawn (simulating the driver-side reservation of design §5.3). |
| 105 | pub fn set_budget(&self, total: Option<u64>, spend_per_task: u64) { |
| 106 | let mut inner = self.lock(); |
| 107 | inner.budget = BudgetSnapshot { total, spent: 0 }; |
| 108 | inner.spend_per_task = spend_per_task; |
| 109 | } |
| 110 | |
| 111 | /// Every request received so far, in spawn order. |
| 112 | pub fn requests(&self) -> Vec<TaskRequest> { |
| 113 | self.lock().requests.clone() |
| 114 | } |
| 115 | |
| 116 | /// Descriptions of every request, in spawn order. |
| 117 | pub fn request_descriptions(&self) -> Vec<String> { |
| 118 | self.lock() |
| 119 | .requests |
| 120 | .iter() |
| 121 | .map(|request| request.description.clone()) |
| 122 | .collect() |
| 123 | } |
| 124 | |
| 125 | /// Number of admitted spawn calls. |
| 126 | pub fn spawn_count(&self) -> usize { |
| 127 | self.lock().requests.len() |
| 128 | } |
| 129 | |
| 130 | /// Every progress event received so far, in emit order. |
| 131 | pub fn events(&self) -> Vec<ProgressEvent> { |
| 132 | self.lock().events.clone() |
| 133 | } |
| 134 | |
| 135 | /// How many times `cancel_all` has been invoked. |
| 136 | pub fn cancel_all_calls(&self) -> usize { |
| 137 | self.cancel_calls.load(Ordering::SeqCst) |
| 138 | } |
| 139 | |
| 140 | fn lock(&self) -> std::sync::MutexGuard<'_, Inner> { |
| 141 | self.inner.lock().expect("FakeDriver mutex poisoned") |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | #[async_trait] |
| 146 | impl WorkflowDriver for FakeDriver { |
| 147 | async fn spawn_task(&self, request: TaskRequest) -> Result<SpawnedTask, DriverError> { |
| 148 | let (task_id, reply, delay) = { |
| 149 | let mut inner = self.lock(); |
| 150 | let matched = inner |
| 151 | .rules |
| 152 | .iter() |
| 153 | .find(|rule| request.description.contains(&rule.needle)) |
| 154 | .map(|rule| (rule.reply.clone(), rule.delay)); |
| 155 | let (reply, delay) = matched.unwrap_or_else(|| { |
| 156 | ( |
| 157 | FakeReply::Complete(format!("done:{}", request.description)), |
| 158 | None, |
| 159 | ) |
| 160 | }); |
| 161 | match reply { |
| 162 | FakeReply::Reject(message) => return Err(DriverError::Rejected(message)), |
| 163 | FakeReply::Unavailable(message) => { |
| 164 | return Err(DriverError::Unavailable(message)); |
| 165 | } |
| 166 | _ => {} |
| 167 | } |
| 168 | inner.requests.push(request); |
| 169 | inner.budget.spent += inner.spend_per_task; |
| 170 | inner.next_id += 1; |
| 171 | (format!("agent_{:04}", inner.next_id), reply, delay) |
| 172 | }; |
| 173 | if matches!(reply, FakeReply::HoldAdmission) { |
| 174 | return std::future::pending().await; |
| 175 | } |
| 176 | |
| 177 | let (tx, rx) = oneshot::channel(); |
| 178 | match reply { |
| 179 | FakeReply::Never => self.lock().held.push(tx), |
| 180 | FakeReply::DropCompletion => drop(tx), |
| 181 | reply => { |
| 182 | let completion = match reply { |
| 183 | FakeReply::Complete(text) => TaskCompletion::Completed { text }, |
| 184 | FakeReply::Fail(message) => TaskCompletion::Failed { message }, |
| 185 | FakeReply::Cancelled => TaskCompletion::Cancelled, |
| 186 | FakeReply::BudgetExhausted(message) => { |
| 187 | TaskCompletion::BudgetExhausted { message } |
| 188 | } |
| 189 | FakeReply::Reject(_) |
| 190 | | FakeReply::Unavailable(_) |
| 191 | | FakeReply::Never |
| 192 | | FakeReply::HoldAdmission |
| 193 | | FakeReply::DropCompletion => unreachable!("handled above"), |
| 194 | }; |
| 195 | match delay { |
| 196 | None => { |
| 197 | let _ = tx.send(completion); |
| 198 | } |
| 199 | Some(delay) => { |
| 200 | tokio::spawn(async move { |
| 201 | tokio::time::sleep(delay).await; |
| 202 | let _ = tx.send(completion); |
| 203 | }); |
| 204 | } |
| 205 | } |
| 206 | } |
| 207 | } |
| 208 | Ok(SpawnedTask { |
| 209 | task_id, |
| 210 | completion: rx, |
| 211 | }) |
| 212 | } |
| 213 | |
| 214 | fn cancel_all(&self) { |
| 215 | self.cancel_calls.fetch_add(1, Ordering::SeqCst); |
| 216 | } |
| 217 | |
| 218 | fn budget(&self) -> BudgetSnapshot { |
| 219 | self.lock().budget |
| 220 | } |
| 221 | |
| 222 | fn progress(&self, event: ProgressEvent) { |
| 223 | self.lock().events.push(event); |
| 224 | } |
| 225 | } |
| 226 |