1 files changed, 73 insertions, 0 deletions
diff --git a/std/util/async_test.ts b/std/util/async_test.ts
new file mode 100644
index 000000000..adaac1e22
--- /dev/null
+++ b/std/util/async_test.ts
@@ -0,0 +1,73 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import { test, runIfMain } from "../testing/mod.ts";
+import { assert, assertEquals, assertStrictEq } from "../testing/asserts.ts";
+import { collectUint8Arrays, deferred, MuxAsyncIterator } 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);
+});
+
+test(async function collectUint8Arrays0(): Promise<void> {
+  async function* gen(): AsyncIterableIterator<Uint8Array> {}
+  const result = await collectUint8Arrays(gen());
+  assert(result instanceof Uint8Array);
+  assertEquals(result.length, 0);
+});
+
+test(async function collectUint8Arrays0(): Promise<void> {
+  async function* gen(): AsyncIterableIterator<Uint8Array> {}
+  const result = await collectUint8Arrays(gen());
+  assert(result instanceof Uint8Array);
+  assertStrictEq(result.length, 0);
+});
+
+test(async function collectUint8Arrays1(): Promise<void> {
+  const buf = new Uint8Array([1, 2, 3]);
+  async function* gen(): AsyncIterableIterator<Uint8Array> {
+    yield buf;
+  }
+  const result = await collectUint8Arrays(gen());
+  assertStrictEq(result, buf);
+  assertStrictEq(result.length, 3);
+});
+
+test(async function collectUint8Arrays4(): Promise<void> {
+  async function* gen(): AsyncIterableIterator<Uint8Array> {
+    yield new Uint8Array([1, 2, 3]);
+    yield new Uint8Array([]);
+    yield new Uint8Array([4, 5]);
+    yield new Uint8Array([6]);
+  }
+  const result = await collectUint8Arrays(gen());
+  assert(result instanceof Uint8Array);
+  assertStrictEq(result.length, 6);
+  for (let i = 0; i < 6; i++) {
+    assertStrictEq(result[i], i + 1);
+  }
+});
+
+runIfMain(import.meta);