1 files changed, 27 insertions, 3 deletions
diff --git a/deno2/js/mock_runtime.js b/deno2/js/mock_runtime.js
index b3ec7f034..97688a08d 100644
--- a/deno2/js/mock_runtime.js
+++ b/deno2/js/mock_runtime.js
@@ -1,18 +1,42 @@
 // A simple runtime that doesn't involve typescript or protobufs to test
 // libdeno.
 const window = eval("this");
-window['foo'] = () => {
+window["foo"] = () => {
   deno_print("Hello world from foo");
   return "foo";
-}
+};
 
 function assert(cond) {
   if (!cond) throw Error("mock_runtime.js assert failed");
 }
 
 function subabc() {
-  deno_sub((msg) => {
+  deno_sub(msg => {
     assert(msg instanceof ArrayBuffer);
     assert(msg.byteLength === 3);
   });
 }
+
+function typedArrayToArrayBuffer(ta) {
+  return ta.buffer.slice(ta.byteOffset, ta.byteOffset + ta.byteLength);
+}
+
+function pubReturnEmpty() {
+  const ui8 = new Uint8Array("abc".split("").map(c => c.charCodeAt(0)));
+  const ab = typedArrayToArrayBuffer(ui8);
+  let r = deno_pub(ab);
+  assert(r == null);
+  r = deno_pub(ab);
+  assert(r == null);
+}
+
+function pubReturnBar() {
+  const ui8 = new Uint8Array("abc".split("").map(c => c.charCodeAt(0)));
+  const ab = typedArrayToArrayBuffer(ui8);
+  const r = deno_pub(ab);
+  assert(r instanceof ArrayBuffer);
+  assert(r.byteLength === 3);
+  const rui8 = new Uint8Array(r);
+  const rstr = String.fromCharCode(...rui8);
+  assert(rstr === "bar");
+}