start a test to see if simulations are deterministic. they... aren't :(

sim/tests/determinism.rs

@@ -0,0 +1,34 @@
+extern crate control;
+extern crate geom;
+extern crate map_model;
+extern crate sim;
+
+#[test]
+fn from_scratch() {
+    // This assumes this map has been built
+    let input = "../data/small.abst";
+    let rng_seed = 42;
+    let spawn_count = 1000;
+
+    println!("Creating two simulations");
+    let data = map_model::load_pb(input).expect("Couldn't load input");
+    let map = map_model::Map::new(&data);
+    let geom_map = geom::GeomMap::new(&map);
+    let control_map = control::ControlMap::new(&map, &geom_map);
+
+    let mut sim1 = sim::straw_model::Sim::new(&map, &geom_map, Some(rng_seed));
+    let mut sim2 = sim::straw_model::Sim::new(&map, &geom_map, Some(rng_seed));
+    sim1.spawn_many_on_empty_roads(spawn_count);
+    sim2.spawn_many_on_empty_roads(spawn_count);
+
+    for _ in 1..1200 {
+        if sim1 != sim2 {
+            // TODO need to sort dicts in json output to compare
+            sim1.write_savestate("sim1_state.json").unwrap();
+            sim2.write_savestate("sim2_state.json").unwrap();
+            panic!("sim state differs at {}. compare sim1_state.json and sim2_state.json", sim1.time);
+        }
+        sim1.step(&geom_map, &map, &control_map);
+        sim2.step(&geom_map, &map, &control_map);
+    }
+}