3 files changed, 29 insertions, 17 deletions
diff --git a/cli/tests/unit/ref_unref_test.ts b/cli/tests/unit/ref_unref_test.ts
new file mode 100644
index 000000000..da6e95efc
--- /dev/null
+++ b/cli/tests/unit/ref_unref_test.ts
@@ -0,0 +1,10 @@
+import { assertNotEquals, execCode } from "./test_util.ts";
+
+Deno.test("[unrefOp] unref'ing invalid ops does not have effects", async () => {
+  const [statusCode, _] = await execCode(`
+    Deno.core.unrefOp(-1);
+    setTimeout(() => { throw new Error() }, 10)
+  `);
+  // Invalid unrefOp call doesn't affect exit condition of event loop
+  assertNotEquals(statusCode, 0);
+});
diff --git a/cli/tests/unit/test_util.ts b/cli/tests/unit/test_util.ts
index 3591864d4..b18ad9550 100644
--- a/cli/tests/unit/test_util.ts
+++ b/cli/tests/unit/test_util.ts
@@ -27,3 +27,21 @@ export function pathToAbsoluteFileUrl(path: string): URL {
 
   return new URL(`file://${Deno.build.os === "windows" ? "/" : ""}${path}`);
 }
+
+const decoder = new TextDecoder();
+
+export async function execCode(code: string) {
+  const p = Deno.run({
+    cmd: [
+      Deno.execPath(),
+      "eval",
+      "--unstable",
+      "--no-check",
+      code,
+    ],
+    stdout: "piped",
+  });
+  const [status, output] = await Promise.all([p.status(), p.output()]);
+  p.close();
+  return [status.code, decoder.decode(output)];
+}
diff --git a/cli/tests/unit/timers_test.ts b/cli/tests/unit/timers_test.ts
index e85a2effc..ac0403bf7 100644
--- a/cli/tests/unit/timers_test.ts
+++ b/cli/tests/unit/timers_test.ts
@@ -6,11 +6,10 @@ import {
   Deferred,
   deferred,
   delay,
+  execCode,
   unreachable,
 } from "./test_util.ts";
 
-const decoder = new TextDecoder();
-
 Deno.test(async function functionParameterBindingSuccess() {
   const promise = deferred();
   let count = 0;
@@ -578,21 +577,6 @@ Deno.test(
   },
 );
 
-async function execCode(code: string) {
-  const p = Deno.run({
-    cmd: [
-      Deno.execPath(),
-      "eval",
-      "--unstable",
-      code,
-    ],
-    stdout: "piped",
-  });
-  const [status, output] = await Promise.all([p.status(), p.output()]);
-  p.close();
-  return [status.code, decoder.decode(output)];
-}
-
 Deno.test({
   name: "unrefTimer",
   permissions: { run: true },