1 files changed, 10 insertions, 0 deletions
diff --git a/deno2/js/mock_runtime.js b/deno2/js/mock_runtime.js
index a91546f85..cd9766685 100644
--- a/deno2/js/mock_runtime.js
+++ b/deno2/js/mock_runtime.js
@@ -7,3 +7,13 @@ window['foo'] = () => {
   return "foo";
 }
 
+function assert(cond) {
+  if (!cond) throw Error("assert failed");
+}
+
+function recvabc() {
+  deno_recv((msg) => {
+    assert(msg instanceof ArrayBuffer);
+    assert(msg.byteLength === 3);
+  });
+}