test(wasm-actor): cycle 59 — local.tee, 16KB payload, dual runtime, i64 wrap (255 tests)

Added 5 tests: local.tee instruction, 16KB payload round-trip, two independent
runtimes with WASM actors, i64-to-i32 wrap instruction, random WAT variations
property test. No new bugs found.

Authored by Claude, lovingly guided by Zachery Aaron Shores-Chmielewski

crates/wasm-actor/tests/wasm_actor.rs

@@ -8679,3 +8679,138 @@ fn builder_accepts_slice_reference() {
     rt.send_to(addr, ByteMessage(vec![])).unwrap();
     rt.tick();
 }
+
+// ── Cycle 59 ─────────────────────────────────────────────────────────────────
+
+// Guest that uses local.tee instruction (sets local and leaves value on stack)
+#[test]
+fn guest_uses_local_tee() {
+    let wat = r#"(module
+        (memory (export "memory") 1)
+        (global $heap (mut i32) (i32.const 65536))
+        (func (export "alloc") (param $len i32) (result i32)
+            global.get $heap
+            global.get $heap
+            local.get $len
+            i32.add
+            global.set $heap)
+        (func (export "handle") (param $ptr i32) (param $len i32)
+            ;; Use local.tee: ptr2 = alloc_start, also keep on stack
+            (local $ptr2 i32)
+            global.get $heap
+            local.tee $ptr2
+            drop ;; just exercising the instruction
+        )
+    )"#;
+    let engine = SharedEngine::new().unwrap();
+    let actor = WasmActorBuilder::new(engine, wat::parse_str(wat).unwrap())
+        .build().unwrap();
+    let rt = Runtime::new(RuntimeConfig::default());
+    let addr = rt.spawn(actor).unwrap();
+    rt.send_to(addr, ByteMessage(b"tee".to_vec())).unwrap();
+    rt.tick(); // no trap
+}
+
+// Guest that writes a 16KB response — tests larger-than-page payloads round-trip
+#[test]
+fn sixteen_kb_payload_round_trip() {
+    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();
+
+    let payload: Vec<u8> = (0..16384u32).map(|i| (i % 251) as u8).collect();
+    rt.send_to(addr, framed_msg(inbox.addr(), &payload)).unwrap();
+    rt.tick();
+
+    let resp = inbox.try_recv().expect("should receive 16KB echo");
+    assert_eq!(resp.0, payload);
+}
+
+// Two runtimes with WASM actors operating independently at the same time
+#[test]
+fn two_independent_runtimes_with_wasm_actors() {
+    let engine = SharedEngine::new().unwrap();
+    let actor1 = WasmActorBuilder::new(engine.clone(), guest_wasm("echo")).build().unwrap();
+    let actor2 = WasmActorBuilder::new(engine, guest_wasm("double")).build().unwrap();
+
+    let rt1 = Runtime::new(RuntimeConfig::default());
+    let rt2 = Runtime::new(RuntimeConfig::default());
+
+    let inbox1 = rt1.new_inbox::<ByteMessage>().unwrap();
+    let inbox2 = rt2.new_inbox::<ByteMessage>().unwrap();
+
+    let addr1 = rt1.spawn(actor1).unwrap();
+    let addr2 = rt2.spawn(actor2).unwrap();
+
+    rt1.send_to(addr1, framed_msg(inbox1.addr(), b"A")).unwrap();
+    rt2.send_to(addr2, framed_msg(inbox2.addr(), b"B")).unwrap();
+
+    rt1.tick();
+    rt2.tick();
+
+    let msgs1: Vec<_> = std::iter::from_fn(|| inbox1.try_recv().map(|m| m.0)).collect();
+    let msgs2: Vec<_> = std::iter::from_fn(|| inbox2.try_recv().map(|m| m.0)).collect();
+
+    assert_eq!(msgs1.len(), 1, "echo from rt1");
+    assert_eq!(msgs2.len(), 2, "double from rt2");
+    assert_eq!(msgs1[0], b"A");
+    assert!(msgs2.iter().all(|m| m == b"B"));
+}
+
+// Guest that uses i32.wrap_i64 instruction
+#[test]
+fn guest_uses_i64_to_i32_wrap() {
+    let wat = r#"(module
+        (memory (export "memory") 1)
+        (global $heap (mut i32) (i32.const 65536))
+        (func (export "alloc") (param $len i32) (result i32)
+            global.get $heap
+            global.get $heap
+            local.get $len
+            i32.add
+            global.set $heap)
+        (func (export "handle") (param $ptr i32) (param $len i32)
+            ;; Wrap i64 to i32: 0x1_0000_00FF -> 0xFF
+            i64.const 4294967551  ;; 0x1_000000FF
+            i32.wrap_i64
+            ;; result is 255, store at ptr
+            local.get $ptr
+            i32.store8 offset=0
+        )
+    )"#;
+    let engine = SharedEngine::new().unwrap();
+    let actor = WasmActorBuilder::new(engine, wat::parse_str(wat).unwrap())
+        .build().unwrap();
+    let rt = Runtime::new(RuntimeConfig::default());
+    let addr = rt.spawn(actor).unwrap();
+    rt.send_to(addr, ByteMessage(b"W".to_vec())).unwrap();
+    rt.tick(); // no trap, wrapping is well-defined
+}
+
+// Property test: building from random subsets of valid WAT always succeeds or fails cleanly
+proptest! {
+    #[test]
+    fn prop_random_valid_wat_variations_never_panic(
+        alloc_offset in 1024u32..60000,
+        pages in 1u32..5,
+        handle_body in proptest::bool::ANY,
+    ) {
+        let store_body = if handle_body {
+            "local.get $ptr\nlocal.get $ptr\ni32.load8_u\ni32.store8"
+        } else {
+            ""
+        };
+        let wat = format!(r#"(module
+            (memory (export "memory") {pages})
+            (func (export "alloc") (param $len i32) (result i32)
+                i32.const {alloc_offset})
+            (func (export "handle") (param $ptr i32) (param $len i32)
+                {store_body})
+        )"#);
+        let engine = SharedEngine::new().unwrap();
+        let result = WasmActorBuilder::new(engine, wat::parse_str(&wat).unwrap()).build();
+        assert!(result.is_ok(), "valid WAT should build");
+    }
+}