unit test that a sim finishes eventually

sim/src/sim.rs

@@ -400,6 +400,12 @@ impl Sim {
         )
     }
 
+    pub fn is_done(&self) -> bool {
+        let (_, active_cars) = self.driving_state.get_active_and_waiting_count();
+        let (_, active_peds) = self.walking_state.get_active_and_waiting_count();
+        active_cars == 0 && active_peds == 0
+    }
+
     pub fn debug_ped(&self, id: PedestrianID) {
         self.walking_state.debug_ped(id);
     }

sim/tests/completion.rs

@@ -0,0 +1,30 @@
+extern crate abstutil;
+extern crate control;
+extern crate map_model;
+extern crate sim;
+
+#[test]
+fn aorta_model_completes() {
+    // This assumes this map has been built
+    let input = "../data/small.abst";
+    let rng_seed = 42;
+    let spawn_count = 100;
+
+    let map = map_model::Map::new(input, &map_model::Edits::new()).expect("Couldn't load map");
+    let control_map = control::ControlMap::new(&map);
+
+    let mut sim = sim::Sim::new(&map, Some(rng_seed), false);
+    sim.seed_pedestrians(&map, spawn_count);
+    sim.seed_parked_cars(0.5);
+    sim.start_many_parked_cars(&map, spawn_count);
+
+    loop {
+        sim.step(&map, &control_map);
+        if sim.time.is_multiple_of_minute() {
+            println!("{}", sim.summary());
+        }
+        if sim.is_done() {
+            break;
+        }
+    }
+}