crates/wasm-actor/tests/wasm_actor.rs

@@ -8405,4 +8405,100 @@ fn drop_runtime_with_live_actors() {
 
     // Drop runtime without stopping actors — should not panic or leak
     drop(rt);
+}
+
+// ── Guest with immutable global ─────────────────────────────────────────────
+
+#[test]
+fn guest_with_immutable_global() {
+    let wat = r#"
+        (module
+            (import "swactor" "send" (func $send (param i32 i32 i32)))
+            (memory (export "memory") 1)
+            (global $magic i32 (i32.const 0xBE))
+
+            (func (export "alloc") (param i32) (result i32) i32.const 4096)
+            (func (export "handle") (param $ptr i32) (param $len i32)
+                (i32.store8 (i32.const 200) (global.get $magic))
+                (call $send (local.get $ptr) (i32.const 200) (i32.const 1))
+            )
+        )
+    "#;
+    let wasm = wat::parse_str(wat).unwrap();
+    let engine = SharedEngine::new().unwrap();
+    let actor = WasmActorBuilder::new(engine, wasm).build().unwrap();
+
+    let rt = Runtime::new(RuntimeConfig::default());
+    let inbox = rt.new_inbox::<ByteMessage>().unwrap();
+    let addr = rt.spawn(actor).unwrap();
+
+    rt.send_to(addr, framed_msg(inbox.addr(), b"g")).unwrap();
+    rt.tick();
+
+    let msg = inbox.try_recv().unwrap();
+    assert_eq!(msg.0[0], 0xBE, "immutable global should return configured value");
+}
+
+// ── Multiple echo round trips (message ping-pong through actor) ─────────────
+
+#[test]
+fn multiple_echo_round_trips() {
+    let engine = SharedEngine::new().unwrap();
+    let actor = WasmActorBuilder::new(engine, guest_wasm("echo")).build().unwrap();
+
+    let rt = Runtime::new(RuntimeConfig::default());
+    let inbox = rt.new_inbox::<ByteMessage>().unwrap();
+    let addr = rt.spawn(actor).unwrap();
+
+    // Send, receive, send the response back to actor, repeat 5 times
+    let mut current_payload = b"ping-0".to_vec();
+    for i in 0..5 {
+        rt.send_to(addr, framed_msg(inbox.addr(), &current_payload)).unwrap();
+        rt.tick();
+        let msg = inbox.try_recv().unwrap_or_else(|| panic!("round {i} should echo"));
+        assert_eq!(msg.0, current_payload);
+        current_payload = format!("ping-{}", i + 1).into_bytes();
+    }
+}
+
+// ── WasmActorBuilder consumed on build — verify not Clone ───────────────────
+
+#[test]
+fn builder_is_consumed_on_build() {
+    // This test verifies the builder pattern by building twice from same config.
+    // Each build call consumes the builder.
+    let engine = SharedEngine::new().unwrap();
+    let wasm = guest_wasm("echo");
+
+    let builder1 = WasmActorBuilder::new(engine.clone(), wasm.clone());
+    let _actor1 = builder1.build().unwrap();
+    // builder1 is consumed — can't call build again (compile error if tried)
+
+    let builder2 = WasmActorBuilder::new(engine, wasm);
+    let _actor2 = builder2.build().unwrap();
+    // Both built successfully from same config
+}
+
+// ── Empty tick between messages doesn't lose them ───────────────────────────
+
+#[test]
+fn empty_tick_between_sends_preserves_order() {
+    let engine = SharedEngine::new().unwrap();
+    let actor = WasmActorBuilder::new(engine, guest_wasm("echo")).build().unwrap();
+
+    let rt = Runtime::new(RuntimeConfig::default());
+    let inbox = rt.new_inbox::<ByteMessage>().unwrap();
+    let addr = rt.spawn(actor).unwrap();
+
+    rt.send_to(addr, framed_msg(inbox.addr(), b"A")).unwrap();
+    rt.tick();
+    rt.tick(); // empty tick
+    rt.send_to(addr, framed_msg(inbox.addr(), b"B")).unwrap();
+    rt.tick();
+    rt.tick(); // empty tick
+    rt.send_to(addr, framed_msg(inbox.addr(), b"C")).unwrap();
+    rt.tick();
+
+    let msgs: Vec<Vec<u8>> = std::iter::from_fn(|| inbox.try_recv().map(|m| m.0)).collect();
+    assert_eq!(msgs, vec![b"A".to_vec(), b"B".to_vec(), b"C".to_vec()]);
 }