1 files changed, 20 insertions, 0 deletions
diff --git a/js/files_test.ts b/js/files_test.ts
new file mode 100644
index 000000000..82af10aa2
--- /dev/null
+++ b/js/files_test.ts
@@ -0,0 +1,20 @@
+// Copyright 2018 the Deno authors. All rights reserved. MIT license.
+
+import * as deno from "deno";
+import { test, assert, assertEqual } from "./test_util.ts";
+
+test(function filesStdioFileDescriptors() {
+  assertEqual(deno.stdin.fd, 0);
+  assertEqual(deno.stdout.fd, 1);
+  assertEqual(deno.stderr.fd, 2);
+});
+
+test(async function filesCopyToStdout() {
+  const filename = "package.json";
+  const file = await deno.open(filename);
+  assert(file.fd > 2);
+  const bytesWritten = await deno.copy(deno.stdout, file);
+  const fileSize = deno.statSync(filename).len;
+  assertEqual(bytesWritten, fileSize);
+  console.log("bytes written", bytesWritten);
+});