1 files changed, 15 insertions, 0 deletions
diff --git a/cli/js/tests/performance_test.ts b/cli/js/tests/performance_test.ts
new file mode 100644
index 000000000..89b7cad8b
--- /dev/null
+++ b/cli/js/tests/performance_test.ts
@@ -0,0 +1,15 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+import { unitTest, assert, createResolvable } from "./test_util.ts";
+
+unitTest({ perms: { hrtime: false } }, async function performanceNow(): Promise<
+  void
+> {
+  const resolvable = createResolvable();
+  const start = performance.now();
+  setTimeout((): void => {
+    const end = performance.now();
+    assert(end - start >= 10);
+    resolvable.resolve();
+  }, 10);
+  await resolvable;
+});