Add mock_runtime_test for deno_last_exception.

2 files changed, 7 insertions, 5 deletions

diff --git a/js/mock_runtime.js b/js/mock_runtime.js
index 313a7fac7..b4f353cdc 100644
--- a/js/mock_runtime.js
+++ b/js/mock_runtime.js
@@ -31,9 +31,8 @@ global.SendSuccess = () => {
   });
 };
 
-global.SendByteLength = () => {
+global.SendWrongByteLength = () => {
   deno.recv(msg => {
-    assert(msg instanceof ArrayBuffer);
     assert(msg.byteLength === 3);
   });
 };
diff --git a/src/mock_runtime_test.cc b/src/mock_runtime_test.cc
index 971fa68f3..a2c4b3699 100644
--- a/src/mock_runtime_test.cc
+++ b/src/mock_runtime_test.cc
@@ -41,11 +41,14 @@ TEST(MockRuntimeTest, SendSuccess) {
   deno_delete(d);
 }
 
-TEST(MockRuntimeTest, SendByteLength) {
+TEST(MockRuntimeTest, SendWrongByteLength) {
   Deno* d = deno_new(nullptr, nullptr);
-  EXPECT_TRUE(deno_execute(d, "a.js", "SendByteLength()"));
-  // We pub the wrong sized message, it should throw.
+  EXPECT_TRUE(deno_execute(d, "a.js", "SendWrongByteLength()"));
+  // deno_send the wrong sized message, it should throw.
   EXPECT_FALSE(deno_send(d, strbuf("abcd")));
+  std::string exception = deno_last_exception(d);
+  EXPECT_GT(exception.length(), 1);
+  EXPECT_NE(exception.find("assert"), std::string::npos);
   deno_delete(d);
 }