1 files changed, 51 insertions, 0 deletions
diff --git a/std/io/util_test.ts b/std/io/util_test.ts
new file mode 100644
index 000000000..c616a4bba
--- /dev/null
+++ b/std/io/util_test.ts
@@ -0,0 +1,51 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+const { remove } = Deno;
+import { test } from "../testing/mod.ts";
+import { assert, assertEquals } from "../testing/asserts.ts";
+import { copyBytes, tempFile } from "./util.ts";
+import * as path from "../fs/path.ts";
+
+test(function testCopyBytes(): void {
+  const dst = new Uint8Array(4);
+
+  dst.fill(0);
+  let src = Uint8Array.of(1, 2);
+  let len = copyBytes(dst, src, 0);
+  assert(len === 2);
+  assertEquals(dst, Uint8Array.of(1, 2, 0, 0));
+
+  dst.fill(0);
+  src = Uint8Array.of(1, 2);
+  len = copyBytes(dst, src, 1);
+  assert(len === 2);
+  assertEquals(dst, Uint8Array.of(0, 1, 2, 0));
+
+  dst.fill(0);
+  src = Uint8Array.of(1, 2, 3, 4, 5);
+  len = copyBytes(dst, src);
+  assert(len === 4);
+  assertEquals(dst, Uint8Array.of(1, 2, 3, 4));
+
+  dst.fill(0);
+  src = Uint8Array.of(1, 2);
+  len = copyBytes(dst, src, 100);
+  assert(len === 0);
+  assertEquals(dst, Uint8Array.of(0, 0, 0, 0));
+
+  dst.fill(0);
+  src = Uint8Array.of(3, 4);
+  len = copyBytes(dst, src, -2);
+  assert(len === 2);
+  assertEquals(dst, Uint8Array.of(3, 4, 0, 0));
+});
+
+test(async function ioTempfile(): Promise<void> {
+  const f = await tempFile(".", {
+    prefix: "prefix-",
+    postfix: "-postfix"
+  });
+  console.log(f.file, f.filepath);
+  const base = path.basename(f.filepath);
+  assert(!!base.match(/^prefix-.+?-postfix$/));
+  await remove(f.filepath);
+});