1 files changed, 34 insertions, 0 deletions
diff --git a/util/async_test.ts b/util/async_test.ts
new file mode 100644
index 000000000..c704002d4
--- /dev/null
+++ b/util/async_test.ts
@@ -0,0 +1,34 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import { test, runIfMain } from "../testing/mod.ts";
+import { assertEquals } from "../testing/asserts.ts";
+import { MuxAsyncIterator, deferred } from "./async.ts";
+
+test(async function asyncDeferred(): Promise<void> {
+  const d = deferred<number>();
+  d.resolve(12);
+});
+
+async function* gen123(): AsyncIterableIterator<number> {
+  yield 1;
+  yield 2;
+  yield 3;
+}
+
+async function* gen456(): AsyncIterableIterator<number> {
+  yield 4;
+  yield 5;
+  yield 6;
+}
+
+test(async function asyncMuxAsyncIterator(): Promise<void> {
+  const mux = new MuxAsyncIterator<number>();
+  mux.add(gen123());
+  mux.add(gen456());
+  const results = new Set();
+  for await (const value of mux) {
+    results.add(value);
+  }
+  assertEquals(results.size, 6);
+});
+
+runIfMain(import.meta);