add treetest protocol simulator and ui

treetest/tests/protocol_basics.rs

@@ -0,0 +1,43 @@
+use treetest::{scenarios::built_in_scenarios, sim::Simulation};
+
+#[test]
+fn endpoint_and_leaf_introspection_complete_successfully() {
+    let scenarios = built_in_scenarios();
+    let mut simulation = Simulation::new(scenarios[0].clone()).expect("scenario should build");
+
+    simulation
+        .call_endpoint_introspection(treetest::model::NodeId(1))
+        .expect("endpoint introspection should start");
+    simulation.drain().expect("network should drain");
+    assert!(simulation.latest_root_data_text().is_some());
+
+    simulation
+        .call_leaf_introspection(treetest::model::NodeId(1), "echo")
+        .expect("leaf introspection should start");
+    simulation.drain().expect("network should drain");
+    assert!(simulation.latest_root_data_text().is_some());
+}
+
+#[test]
+fn echo_leaf_round_trips_user_payload() {
+    let scenarios = built_in_scenarios();
+    let mut simulation = Simulation::new(scenarios[1].clone()).expect("scenario should build");
+
+    simulation
+        .call_echo_leaf(treetest::model::NodeId(1), "echo", "hello from test")
+        .expect("echo call should start");
+    simulation.drain().expect("network should drain");
+
+    assert_eq!(
+        simulation.latest_root_data_text().as_deref(),
+        Some("hello from test")
+    );
+    let hook_id = *simulation.hook_ids().last().expect("hook should exist");
+    assert!(
+        simulation
+            .hooks
+            .get(&hook_id)
+            .expect("hook snapshot should exist")
+            .closed
+    );
+}